Earticle

This paper aims to compare the mean object size of M/G/1/PS model with that of M/BP/1 model used in the web service. The mean object size is one of important measure to control and manage web service economically. M/G/1/PS model utilizes the processor sharing in which CPU rotates in round-robin order giving time quantum to multiple tasks. M/BP/1 model uses the Bounded Pareto distribution to describe the web service according to file size. We may infer that the mean waiting latencies of M/G/1/PS and M/BP/1 model are equal to the mean waiting latency of the deterministic model using the round robin scheduling with the time quantum. Based on the inference, we can find the mean object size of M/G/1/PS model and M/BP/1 model, respectively. Numerical experiments show that when the system load is smaller than the medium, the mean object sizes of the M/G/1/PS model and the M/BP/1 model become the same. In particular, when the shaping parameter is 1.5 and the lower and upper bound of the file size is small in the M/BP/1 model, the mean object sizes of M/G/1/PS model and M/BP/1 model are the same. These results confirm that it is beneficial to use a small file size in a web service.

In this paper, we propose a method of reconstructing the file system to obtain digital forensics information from the APFS file system when meta information that can know the structure of the file system is deleted due to partial damage to the disk. This method is to reconstruct the tree structure of the file system by only retrieving the B-tree node where file/directory information is stored. This method is not a method of constructing nodes based on structural information such as Container Superblock (NXSB) and Volume Checkpoint Superblock (APSB), and B-tree root and leaf node information. The entire disk cluster is traversed to find scattered B-tree leaf nodes and to gather all the information in the file system to build information. It is a method of reconstructing a tree structure of a file/directory based on refined essential data by removing duplicate data. We demonstrate that the proposed method is valid through the results of applying the proposed method by generating numbers of user files and directories.

In this study, we wanted to examine the new vulnerability ‘Dirty Pipe’ that is founded in Linux kernel. how it’s exploited and what is the limitation, where it’s existed, and overcome techniques and analysis of the Linux kernel package. The study of the method used the hmark[1] program to check the vulnerabilities. Hmark is a whitebox testing tool that helps to analyze the vulnerability based on static whitebox testing and automated verification. For this purpose of our study, we analyzed Linux kernel code that is downloaded from an open-source website. Then by analyzing the hmark tool results, we identified in which file of the kernel it exists, cvss level, statistically depicted vulnerabilities on graph which is easy to understand. Furthermore, we will talk about some software we can use to analyze a vulnerability and how hmark software works. In the case of the Dirty Pipe vulnerability in Linux allows non-privileged users to execute malicious code capable of a host of destructive actions including installing backdoors into the system, injecting code into scripts, altering binaries used by elevated programs, and creating unauthorized user profiles. This bug is being tracked as CVE-2022-0847 and has been termed "Dirty Pipe"[2] since it bears a close resemblance to Dirty Cow[3], and easily exploitable Linux vulnerability from 2016 which granted a bad actor an identical level of privileges and powers.

Recently, with the development of mobile computing power, mobile-based VR and AR services are being developed. Due to network performance and computing power constraints, VR and AR services using largecapacity 3D content have limitations. A study on an efficient 3D content load method for a mobile device is required. The conventional method downloads all 3D content used for AR services at the same time. In this paper, we propose an active 3D content load according to the user's track. The proposed method is a partitioned 3D object load. Edge servers were installed for each area and connected through the MESH network. Partitioned load the required 3D object in the area referring to the user's location. The location is identified through the edge server information of the connected AP. The performance of the proposed method and the conventional method was compared. As a result of the comparison, the proposed method showed a stable Mobile AR Service. The results of this study, it is expected to contribute to the activation of edge serverbased AR mobile services.

This study investigates the influence of consumer needs pertaining to brand social media pages on the consumer brand attachment formation process. We collected 278 valid responses from females who have experienced the food brands’ social media pages. Following the data analysis, we developed the results as follows. First, we examined the significant influence of attachment to brand social media page needs and socialization needs on consumer content consumption engagement and content contribution engagement on brand social media pages. Then we determined that consumer engagement significantly influenced consumer brand attachment. Finally, we found consumer consumption engagement exerted a significant mediation effect on the relationship between consumer needs and brand attachment. Based on the results, we outlined the potential theoretical and marketing strategy implications of this research.

The purpose of this study is to prove the global OTT, Netflix’s organizational resilience (OR). For this, we review previous literatures regarding Netflix’s OR and the theoretical logic of the OR. Then, we investigate Netflix’s organizational culture (OC), corporate structure and business strategies based on the five levers of the OR. As a result, the first lever, the coordination makes Netflix to get rid of the inner wall by creating Netflix terms like ‘sunshining,’ and ‘postmortem,’ which makes their employees extraordinarily candid with each other. The second lever, the cooperation provides employees with understanding customers by sharing company and service information openly and broadly through transparent board system, billboard advertising, etc. The third lever, the clout allows Netflix to encourage independent decision-making by their employees. Netflix customers are under scrutiny and served 24/7 via live chat or phone by supporting a high-performance workplace. The fourth lever, the capabilities are related to Netflix’s keeping highly effective people and it establishes a culture of highly motivated employees. The “dream team” policy is run by what is known as the “keeper test.” The last lever, the connections make Netflix to forge external strategic partnership to stay agile. There is no rule for partnering with key content producers by allowing creative freedom to them.

This study tried to confirm the mediating effect of positive psychological capital on the relationship between the communication Competence of managers who are recognized as organizational members working in the company and the adaptive performance of the members. To this end, the research hypothesis established through the final 255 data was verified as follows using the SPSS 21.00 and AMOS 21.1 version statistical programs. First, the higher the manager's communication Competence, the higher the positive psychological capital of organizational members. Second, the higher the communication Competence of the manager, the higher the adaptive performance of the members. Third, as the positive psychological capital of organizational members improved, adaptation performance improved. Fourth, positive psychological capital showed a partial mediating effect between the manager's communication Competence and the member's adaptive performance. The results of this study empirically analyzed the relationship between manager's communication Competence and members' positive psychological capital assumption (+) on the improvement of organizational members' adaptive performance ability. This study has the meaning of the most important research in that it provides additional theoretical and practical implications in the face of insufficient research on factors affecting the adaptation performance of organizational members.

Two wavelength reconfigurable optical nodes are designed. One for 20km or shorter link length, and the other for up to 60km link length. While the first one requires no dispersion compensation, the latter needs dispersion compensation fiber included in the node, which requires additional optical amplifier to compensate the insertion loss of DCF. We calculate all the optical path losses in both cases using the typical value of optical components in the market to see the feasibility of the designed optical node. The minimum received power in the node is calculated to be -21.5dBm without DCF and -12.5dBm with DCF, respectively. These received powers are above the receiver sensitivity both for OC-48 and OC-192 according to the previous work.

In this paper, we propose the new technique adopting power control to MIMO(multi-input multi-output)-OFDMA(orthogonal frequency division multiplexing Access) system with multi-beamformer. The proposed power controlling algorithm for MIMO-OFDMA allocates the transmitting power of each subcarrier based on the CSI(channel state information) and the interference signal. CSI is feedback from base station to mobile station to decide the transmitting power of each subcarrier. Through the proposed technique, we can control iteratively the transmitting power and update the weight of beamformer simultaneously. Therefore, the SNIR of each subcarrier become to converge the target SNIR and the beam is formed toward the desired direction. And the performance of MIMO-OFDMA system with the proposed approach is very improved. The improvement in bit error rate is investigated through computer simulation of a MIMO-OFDMA system with the proposed approach.

Towards the sixth generation (6G) mobile networks, spectrum and energy efficiency of non-orthogonal multiple access (NOMA) transmissions in the fifth generation (5G) wireless system have been improved by intelligent reflecting surface (IRS) technologies. However, the reflecting devices of an IRS tend to be correlated because they are placed close on the surface each other. In this paper, we present an analysis on the correlated IRS in NOMA cellular networks. Specifically, we consider the bit-error rate (BER) performances for correlated-IRS in NOMA networks. First, based on the central limit theorem, we derive an approximate analytical expression of the BER for correlated-IRS NOMA systems, by using the second moment of the channel gain. Then we validate the proposed analytical BER by Monte Carlo simulations, and show that they are in good agreement. In addition, we also show numerically the BER improvement of the correlated-IRS NOMA over the conventional independent-IRS NOMA.

In this study, keywords from representative online portal sites such as NAVER, Google, and Youtube were collected based on text mining analysis technique using TEXTOM to check the changes in the restaurant industry before and after COVID-19. The collection keywords were selected as dining out, food service industry, and dining out culture. For the collected data, the top 30 words were derived, respectively, through the refinement process. In addition, comparative analysis was conducted by defining data from 2018 to 2019 before COVID-19, and from 2020 to 2021 after COVID-19. As a result, 8272 keywords before COVID-19 and 9654 keywords after COVID-19, a total of 17926 keywords, were derived. In order for the food service industry to develop after the COVID-19 pandemic, it is necessary to commercialize the recipes of restaurants to revitalize the distribution of home-use food products that replace home-cooked meals such as meal kits. Due to the social distancing caused by COVID-19, the dining out culture has changed and the trend has changed, and it has been confirmed that the consumption culture has changed to eating and delivering at home more safely than visiting restaurants. In addition, it has been confirmed that the consumption culture of existing consumers is changing to a trend of cooking at home rather than visiting restaurants.

Major developed countries are seriously considering smart factories to increase their manufacturing competitiveness. Smart factory is a customized factory that incorporates ICT in the entire process from product planning to design, distribution and sales. This can reduce production costs and respond flexibly to the consumer market. The smart factory converts physical signals into digital signals, connects machines, parts, factories, manufacturing processes, people, and supply chain partners in the factory to each other, and uses the collected data to enable the smart factory platform to operate intelligently. Enhancing personalized value is the key. Therefore, it can be said that the success or failure of a smart factory depends on whether big data is secured and utilized. Standardized communication and collaboration are required to smoothly acquire big data inside and outside the factory in the smart factory, and the use of big data can be maximized through big data analysis. This study examines big data analysis and standardization in smart factory. Manufacturing innovation by country, smart factory construction framework, smart factory implementation key elements, big data analysis and visualization, etc. will be reviewed first. Through this, we propose services such as big data infrastructure construction process, big data platform components, big data modeling, big data quality management components, big data standardization, and big data implementation consulting that can be suggested when building big data infrastructure in smart factories. It is expected that this proposal can be a guide for building big data infrastructure for companies that want to introduce a smart factory.

In Korea, the military has been conducting counseling for the preemptive detection of psychologically unstable soldiers to prevent unexpected accidents and to help them adapt to military life. However, several soldiers feel anxious about face-to-face counseling with military officers and they have difficulty expressing themselves. Video See-Through HMD is a state-of-the-art mixed reality device that converts the user's real view into a digital view, which leads users to feel the actual situation as the virtual. To validate its usefulness as a new psychological counseling aid, we investigated 11 army soldiers who are under the counseling program in barracks. During the counseling conversation, participants were asked to wear or take off the Video See-Through HMD repeatedly. All conversations were recorded for behavioral observation. As a result, 80% of the soldiers showed a relatively stable state of mind when wearing the Video See-Through HMD, which leads them to be innocent and frank about their concerns. This method could improve the effectiveness of counseling to prevent unexpected accidents caused by unnoticeable psychological instabilities of the clients.

Autism (ASD) is a mental disorder characterized by a pronounced deficit in personal, social, speech, and other aspects of development and communication skills. Since autism is a complex developmental disorder that requires a lot of effort to recognize, this research was conducted to develop an interactive data Acquisition System and detect the first signs of ASD in children. The proposed system presents several variants of the tasks in an entertaining form, using hand tracking. Hand tracking is used to attract children's attention and interest them more to achieve more accurate results. The creation of the system is based on such libraries as OpenCV, PyGame, TensorFlow, and Mediapipe. The ultimate goal of the paper is to obtain data on the disease of autism in children for use in further diagnosis by medical experts.

Barrage is an interactive method based on video, and the video itself is visualized from the viewer's point of view to play people's emotions, and it already has an advantage in communication by attracting people's attention using stories and plays. Advances in digital and mobile technology have enabled video viewing anytime, anywhere. Due to the nature of the barrage site that relies on the same video content or playback to participate in video sharing through computers or mobile clients, a barrage that can express users' feelings and thoughts will be added, breaking down the limit of content acceptance by a single user. Barrage satisfy users' entertainment needs, and their influence is growing. Gradually, they are heading to offline movie theaters and TV from barrage videos on the Internet. Attempts to function as offline ammunition facilitated technological innovation for media convergence by converging mobile media with PCs and screens. At the same time, the trend of media convergence shown by coal screens is also a trend of overall technological development. A barrage is an extension of human communication skills. The properties of the barrage fit well with the need for experiential marketing (via video). It can provide a visual experience and create an atmosphere of "surrounding and watching" and eliminate loneliness. Barrage itself provides a function to comment on videos, which is a trigger point for the reason, and donation adds to the amount of information in the video, adding to the fun of the video. Through the barrage, sarcastic, teasing, and expressing emotions can bring entertainment experiences, and users can produce and communicate their shooting text while consuming the satisfaction brought by the shooting. At the same time, Barrage attaches great importance to the needs of the masses, is more individual and diversified, and has commercial significance in line with the current development trend of the Internet. As a new interactive method, barrage contains huge potential value. However, the impact of the interactive way of barrage should also be viewed from a dialectical point of view, how to solve the difficulties in the development of barrage. The way to solve the difficulties in the development of barrage is worth studying. This research will analyze the reasons for the development of barrage and the analysis of Chinese barrage websites, the case analysis of barrage videos, the exploration of the characteristics and values of barrage, and the problems in the process of barrage communication. Provide reference for the development of industrial culture.

This study aims to explore how college students have adjusted to Internet-based learning (IBL) since the pandemic and how they have subjectively experienced their Internet-based classes including live-streaming and recorded classes. We conducted a qualitative study on 16 college students in South Korea. The analysis of the in-depth interviews revealed that despite early negative experiences regarding adjustment to IBL, the participants seemed to have developed an increased sense of control over their learning and simultaneously reported a greater need for self-discipline and social support in order to stay motivated. Also, instructors’ digital competence and creative attempts to facilitate class communication and discussion appeared to have influence on successful IBL. Lastly, the participants’ physical learning environments seemed to impact their online learning in terms of their level of alertness and motivation for study. Implications and suggestions were discussed.

In this paper, we employ deep neural network (DNN) to discern Android user interaction data distribution from artificial data distribution. We utilize real Android user interaction trace dataset collected from [1] to evaluate our DNN design. In particular, we use sequential model with 4 dense hidden layers and 1 dense output layer in TensorFlow and Keras. We also deploy sigmoid activation function for a dense output layer with 1 neuron and ReLU activation function for each dense hidden layer with 32 neurons. Our evaluation shows that our DNN design fulfills high test accuracy of at least 0.9955 and low test loss of at most 0.0116 in all cases of artificial data distributions.

In recent years, the application of deep learning method to computer vision has shown to achieve great performances. Thus, many research projects have also applied deep learning technology to railroad defect detection. In this paper, we have reviewed the researches that applied computer vision based deep learning method to railroad defect detection and inspection, and have discussed the current trend and the direction of those researches. Many research projects were targeted to operate automatically without visual inspection of human and to work in real-time. Therefore, methods to speed up the computation were also investigated. The reduction of the number of learning parameters was considered important to improve computation efficiency. In addition to computation speed issue, the problem of annotation was also discussed in some research projects. To alleviate the problem of time consuming annotation, some kinds of automatic segmentation of the railroad defect or self-supervised methods have been suggested.

In recent years, Unreal Engine has been increasingly included in the animation process produced in the studio. In this case, there will be more than one of main software, and it is very important to accurately transfer data between the software and Unreal Engine. In animation data, not only the animation data of the character but also the animation data of objects interacting with the character must be individually produced and transferred. Most of the objects that interact with the character have a condition of constraints with the part of character. In this paper, I tried to stipulate the production process for extracting animation data of constrained objects, and to analyze why users experience difficulties due to the complexity of the regulations in the process of executing them. And based on the flowchart prescribed for user convenience, I created a program using a Python script to prove the user's convenience. Finally, by comparing the results generated according to the manual flowchart with the results generated through the script command, it was found that the data were consistent.

Recently, NAND-type flash memory has been regarded to be new promising storage media for large-scale database systems. For flash memory to be employed for that purpose, we need to reduce its expensive update cost caused by the inablity of in-place updates. To remedy such a drawback in flash memory, we propose a new flash-aware buffering scheme that enables virtual flushing of dirty pages. To this end, we slightly alter the tradional algorithms used for the logging scheme and buffer management scheme. By using the mechanism of virtual flushing, our proposed buffering scheme can efficiently prevent the frequenct occureces of page updates in flash storage. Besides the advantage of reduced page updates, the proposed viurtual flushing mechanism works favorably for shorneing a recocery time in the presense of failure. This is because it can reduce the time for redo actions during a recovry process. Owing to those two benefits, we can say that our scheme couble be very profitable when it is incorporated into cutting-edge flash-based database systems.

Purpose: In this paper, we show our blending ratio of 10 types of Essential Oils that survives beneficial bacteria and kills harmful bacteria in the scalp, and we investigate the possibility of application of our blending ratio to the development of anti-dandruff products and the possibility of being used as a raw material for clinical beauty and customized cosmetics. Methods: The scalp microorganisms used in our study were M. furfur, S. epidermidis, E. coli, and P. nitroreducens. There are a total of 10 Essential Oils such as True Lavender, Lime, Roman chamomile, Rosemary camphor, Cedarwood, Geranium, Clove, Tea tree, Palmalosa, and Peppermint. The antibacterial test of the blended Essential Oil was carried out according to the test method of the standardized evaluation methodology of “Food and Food Additives Code”. Since M. furfur is related to the growth of sebum in the scalp, in this study we used the fnLNB and the fnLNA with 20 ㎖ of whole fat cow milk added. Results: The blending ratio of EO, which inhibits dandruff-causing bacteria such as M. furfur, S. epidermidis, E. coli, and does not inhibit P. nitroreducens showing dominant growth in a healthy scalp, was B8(Clove 0.2%, Roman chamomile 0.5%, Tea tree 0.3%), B9(Geranium 0.1%, Palmarosa 0.1%, Roman chamomile 0.5%, Tea tree 0.3%), B10(Clove 0.1%, Geranium 0.1%, Palmarosa 0.1%, Roman chamomile 0.5%, Tea tree 0.2%). Conclusion: It is thought that the blending ratio of BEO obtained as a result of this study can provide a basis for use as an alternative to antibiotics in developing anti-dandruff drugs and emerge as a new alternative to solve scalp microbial imbalance. In order for EO to be used as a useful raw material for anti-dandruff preparation, researches on 1) Standardization (the effects of products differ according to the types, regions, climate, extraction methods, etc.), 2) Antimicrobial effects, 3) Safety, etc., must be established.

This study analyzed the effects of the all-in-one automatic fire shutter (hereinafter referred to as “all-in-one shutter”) installed along the fire compartment in a five-story high school building on the evacuation time by using the Pathfinder simulation program. When the all-in-one shutter was added as a new variable, the evacuation time was delayed, indicating insufficient evacuation safety. The evacuation time exceeded the appropriate standard when the evacuation exit was designated to the students in the present state of being placed on the 2nd, 3rd, and 4th floors and the all-in-one shutter was activated. When students were placed on the 1st, 2nd and 3rd floors under the same conditions, the evacuation time was also greatly exceeded. However, when the width of the entrance was set to 130cm, the evacuation time was almost the same as when the all-in-one shutter was not installed. In high-rise school buildings, the bottleneck caused by all-in-one shutters is becoming a major factor in evacuation barriers. To ensure the evacuation safety of school buildings, it has been judged that evacuation education and training to predict the evacuation time required through the all-in-one shutter entrance and induce an evacuation procedure suitable for the standard evacuation time should be carried out in parallel. The implications of this study and suggestions for effective fire compartments and follow-up studies were discussed.

The 2018 Seoul Zero Pay is a policy actively promoted by the government as an economic stimulus package for small business owners and the self-employed who are experiencing economic depression due to COVID-19. However, the controversy over the effectiveness of Zero Pay continues even after two years have passed since the implementation of the policy. Zero Pay is a joint QR code mobile payment service introduced by the government, Seoul city, financial companies, and private simple payment providers to reduce the burden of card merchant fees for small business owners and self-employed people who are experiencing economic difficulties due to the economic downturn. , it was attempted in the direction of economic revitalization for the return of alleyways[1].Therefore, this study intends to draw implications for improvement measures so that the ongoing zero-pay can be further activated and the economy can be settled normally. The analysis results of this study are as follows. First, it shows the effect of increasing the income of small business owners by inducing consumption in alleyways through the economic revitalization policy of Zero Pay. Second, the issuance and distribution of Zero Pay helps to revitalize the local economy and contribute to the establishment of a virtuous cycle system. Third, stable operation is being realized by the introduction of blockchain technology to the Zero Pay platform. In terms of academic significance, the direction of Zero Pay's policies and systems was able to identify changes in the use of Zero Pay through big data analysis. The implementation of the zero-pay policy is in its infancy, and there are limitations in factors for examining the consumer image perception of zero-pay as there are insufficient prior studies. Therefore, continuous follow-up research on Zero Pay should be conducted.

The purpose of this study is to investigate the structural relationship between the viewing motivation, viewing commitment, re-audience intention, and game use intention of e-sports competition broadcast viewers. According to the purpose of the study, an online survey was conducted on 300 college students with experience watching broadcasting of e-sports competitions. After excluding inappropriate data from 8 out of 300 people, 292 people's data were used for final data processing. For data processing, the validity and reliability were verified using SPSS 26 and AMOS 23, and then the research hypothesis was verified. We has the results were shown as follows. First, it was found that entertainment, social intercourse and vicarious satisfaction had a positive effect on viewing commitment, but information has not significantly effect on viewing commitment. Second, it was found that viewing commitment had a positive effect on reviewing intention and game use intention. Third, it was found that reviewing intention had a positive effect on game use intention.

The purpose of this study is to investigate the structural relationship between media engagement, viewing immersion, viewing satisfaction, and loyalty of e-sports viewers. In order to achieve the purpose of this study, a survey was conducted on 300 college students with experience in watching e-sports in Seoul, Gyeonggi-do, and Chungnam. Data processing was done with SPSS 26 for frequency analysis, Cronbach's α analysis. Also, AMOS 13 was used for confirmatory factor analysis and structural equation model analysis. We have the following results. first, among the sub-factors of media engagement, functional engagement and communal engagement had a significant effect on viewing commitment. Second, among the sub-factors of media engagement, emotional engagement had a significant effect on viewing satisfaction. Third, it was found that viewing commitment and viewing satisfaction had a significant effect on loyalty. From the results of this study, it can be seen that the media engagement of e-sports viewers affects loyalty through viewing commitment and viewing satisfaction.

Through this technology development, companies that operate online shopping malls and prospective startups will support education, consulting and expert group matching so that they can solve various issues that may arise in the course of the entire business life cycle, from startups to closures. It is expected that differentiated consulting programs will be designed for companies that currently operate shopping malls and start ups, and customized consulting programs will be provided to improve the effectiveness of consulting while improving customer satisfaction. It is planning to develop a "successful start-up and operation helper" that helps successful start-ups. It is a system that primarily diagnoses problems of prospective entrepreneurs and operators through an automation system at the start-up and operation stage, and professional consultants participate to derive and solve problems, and takes care of all stages of shopping mall birth and growth. In this paper Metaverse based shopping mall Creation is also discussed. Through Big Data creation these accumulated data, we intend to help operators start and operate shopping malls through accurate information by managing all knowledge of shopping malls as a system in the long run.

The purpose of this study was to verify the effectiveness of the computerized cognitive rehabilitation program in which areas and to suggest effective ways to utilize the program in the future, being conducted for 20 college students. We lasted this study from May 3 to 23, 2021. As a result of analyzing the groups using the Computer-based Cognitive Rehabilitation Program (CoTras), in terms of the difference in accuracy for the case of visual perception group B was statistically significantly improved than group C(p<0.05). In the case of attention, memory, and orientation, there was no significant difference between groups(p>0.05). In the case of reaction time difference, there was no significant difference between groups in visual perception, concentration, memory, and orientation(p>0.05). And in order to improve attention and visual perception, it is recommended to conduct the program three times with a duration of 20 minutes, and in order to improve orientation and memory, it can be said that it is helpful to conduct one experiment for at least 30 minutes rather than conducting short and frequent experiments. Through this study, we found that it is effective to apply different times according to each area to improve cognitive function. In other words, depending on the purpose of which cognitive function is to be improved, the duration of the program should be applied differently.

Considering the current situation where cash transactions account for 51.5% of private consumption expenditure, it is very important to secure a tax base by exposing business operators' cash transactions. In the September 2011 national audit, it was pointed out that although a significant part of the investment amount of businesses (VAN operators, etc.) related to the issuance of cash receipts has been recovered, they are still supported through the state tax. At this point in time when a significant amount of the initial investment has been recovered, it is necessary to study a new way to support business operators through methods other than the tax credit method. This study proposes various methods to improve the current cash receipt system and describes the advantages and disadvantages of each method. The most important thing for the improvement of the cash receipt system is that the issuance of cash receipts should be beneficial to business operators. As a result of this study, the most desirable improvement method is to provide differential compensation for the discriminatory cost because the cost is different for each cash receipt operator. For this purpose, we analyze the best way to improve the cash receipt system is a tax credit method and a tax credit for maintenance costs.

In recent years, if we order food by easily accessing the online market with our smartphone, we can receive the product in a fresh state at dawn the next day. Cold chain is an industry that can create high added value because it has both the characteristics of general logistics and sensitivity to temperature. Based on the electrical specifications derived from the reefer container capacity requirement investigation, we proved that power supply to up to 33 reefer containers can be made by using three additional auxiliary power supplies which are applied for freight trains in Korea. In this paper, we conducted a research on a design of power supply system for freight train reefer container based on simulation as a basic research necessary for lowtemperature distribution and cold chain construction based on the reefer container railroad. Consequently, the simulation was conducted using the three-phase inverter diagram in PSIM and the SVPWM (3-harmonic injection method) control technique, and it was verified that the required power voltage was satisfied with 622

In these days, innovative functions are required to unmanned parcel delivery lockers. As non-face-to-face transactions become the center due to the recent COVID-19 pandemic, many problem occurs in society such as theft crimes and lack of loading space. Therefore, New concept storage device is developed in korea. It has the functions that minimizes empty spaces by using the internal transport device to enable efficient space loading and refrigerate goods such as foods. In order to systematically approach the system design of the unmanned parcel delivery lockers which is the new function is applied, We applied model-based system engineering to improve the development efficiency and use a system modeling language to express the system. We conducted interworking research of CAD data including system modeling and design data. it is expected that this method will increase the effective development efficiency such as maintenance traceability and reduction of development period and cost.