Earticle

Wireless Video Sensor Networks (WVSNs) have become a leading solution in many important applications, such as disaster recovery. By using WVSNs in disaster scenarios, the main goal is achieving a successful immediate response including search, location, and rescue operations. The achievement of such an objective in the presence of obstacles and the risk of sensor damage being caused by disasters is a challenging task. In this paper, we propose a fault tolerance model of WVSN for efficient post-disaster management in order to assist rescue and preparedness operations. To get an overview of the monitored area, we used video sensors with a rotation capability that enables them to switch to the best direction for getting better multimedia coverage of the disaster area, while minimizing the effect of occlusions. By constructing different cover sets based on the field of view redundancy, we can provide a robust fault tolerance to the network. We demonstrate by simulating the benefits of our proposal in terms of reliability and high coverage.

The coverage area of GNSS regional ionospheric correction model is mainly determined by the disribution of GNSS ground monitoring stations. Outside the coverage area, GNSS users may receive ionospheric correction signals but the correction does not contain valid correction information. Extrapolation of the correction information can extend the coverage area to some extent. Three interpolation methods, Kriging, biharmonic spline and cubic spline, are tested to evaluate the extrapolation accuracy of the ionospheric delay corrections outside the correction coverage area. IGS (International GNSS Service) ionosphere map data is used to simulate the corrections and to compute the extrapolation error statistics. Among the three methods, biharmonic method yields the best accuracy. The estimation error has a high value during Spring and Fall. The error has a high value in South and East sides and has a low value in North side.

One major problem in the area of wireless sensor networks is the coverage problem. The coverage problem deals with the ability of the network to cover a certain area or some certain events. In this paper, we focus on the area coverage problem. We propose SRAHS, a sensing radius adjusting protocol, to deal with the problem of area coverage. In this protocol, proper sensing radius can be determined using the harmony search algorithm. Due to the proposed protocol accuracy in adjusting the nodes sensing radius, it is able to provide the full coverage in less densities. Moreover, as the result of increasing nodes density, the proposed protocol decreases both the nodes sensing radius and the energy consumption. We have simulated our protocol and simulation results show high efficiency of the proposed protocol

One major problem in the area of wireless sensor networks is the coverage problem. The coverage problem deals with the ability of the network to cover a certain area or some certain events. In this paper, we focus on the area coverage problem. We use a cluster-based coverage control scheme and propose HSSAC protocol to maintain sensing coverage by keeping a small number of active sensor nodes and a small amount of energy consumption in a wireless sensor network. In this protocol, proper active sensor set can be determined using the harmony search algorithm. Due to the proposed protocol accuracy in selecting the active sensor set, it is able to provide the acceptable coverage rate in sparse deployment. As the result of increasing nodes density, the proposed protocol decreases the number of active nodes in the sensor networks. Thus, the proposed protocol decreases the energy consumption of the networks and prolongs the network lifetime. We have simulated our protocol and simulation results show high efficiency of the proposed protocol.

One of the most important problems in the wireless sensor networks is the detection of events in a certain area (target area). This challenge is an important case in the wireless sensor network research and it is named the coverage problem. Regarding the sensors redundancy, we can improve the network lifetime by activating enough number of nodes and making the others sleep. Also, proposing a method that uses the nodes energy equally can prolong the network lifetime. In this paper, we propose a new Energy Based Coverage Method (EBCM). The proposed method decreases the energy consumption and prolongs the network lifetime. The effectiveness of the proposed method is evaluated using NS2 simulator.

In indoor Light Fidelity (Li-Fi) system the position of transmitter and receiver bring different impact on coverage area. Due to Line of sight (LOS) characteristics of Li-Fi, coverage area of a light emitting diode (LED) transmitter plays a vital role for efficient reception of data. In this paper we considered the case when 1 optical receiver can simultaneously receive signal of 2 LED transmitters and present an optimal solution of controlling coverage area of LED transmitter using dimming factor. This paper focuses on efficient reception of data by controlling coverage area of multiple LED transmitters. The performance of proposed dimming factor approach is evaluated by using different dimming based modulation schemes.

Target area coverage is the most fundamental goal of WSN (Wireless Sensor Network) application, so the design of energy aware based algorithm for coverage time maximization becomes a core problem of a large network. For this reason, a DECAR (Distributed-energy and Coverage Aware Routing) protocol is proposed in this paper to realize the goal of network coverage maximization. Specifically, the rest energy and the coverage overlapping degree of the nodes are considered during CH (cluster head) selection process so as to provide more opportunities for the nodes with more rest energy or higher coverage overlapping degree to become CH; like this, the nodes with less rest energy will not be selected as CH, thus to avoid shortening the network lifetime due to early failure of these nodes and balance the network energy consumption. Meanwhile, the main data transmission line composed of CHs is constructed in the data transmission stage in order to improve data transmission efficiency. The simulation result shows: compared with CPCP-ea and EEUC protocols, the proposed DECAR protocol can obtain longer network lifetime and better data coverage ratio.

Coverage algorithm is one of the core technologies required for intelligent robots such as cleaning robots, harvesting robots, painting robots and lawn mowing robots. Although many smart coverage algorithms have been proposed, to the best of our knowledge, all of them make the same assumption that they have sufficient time to cover the entire target area. However, the time to completely cover the whole target area may not always be available. Therefore, in this paper, we propose another new coverage scheme, which we call the DmaxCoverage algorithm that decides the coverage path by considering the deadline for coverage. This approach can be beneficial when the time for the coverage is not sufficient to cover the entire target area. Experimental results show that the DmaxCoverage algorithm outperforms previous algorithms for these situations.

The coverage area of a GNSS regional ionospheric delay model is mainly determined by the distribution of GNSS ground monitoring stations. Extrapolation of the ionospheric model data can extend the coverage area. An extrapolation algorithm, which combines observed ionospheric delay with the environmental parameters, is proposed. Neural network and least square regression algorithms are developed to utilize the combined input data. The bi-harmonic spline method is also tested for comparison. The IGS ionosphere map data is used to simulate the delays and to compute the extrapolation error statistics. The neural network method outperforms the other methods and demonstrates a high extrapolation accuracy. In order to determine the directional characteristics, the estimation error is classified into four direction components. The South extrapolation area yields the largest estimation error followed by North area, which yields the second-largest error.

This paper introduces a method of selecting priority update areas for subdivided land cover maps by training orthoimages and serial cadastral maps in a deep learning model. For the experiment, orthoimages and serial cadastral maps were obtained from the National Spatial Data Infrastructure Portal. Based on the VGG-16 model, 51,470 images were trained on 33 subdivided classifications within the experimental area and an accuracy evaluation was conducted. The overall accuracy was 61.42%. In addition, using the differences in the classification prediction probability of the misclassified polygon and the cosine similarity that numerically expresses the similarity of the land category features with the original subdivided land cover class, the cases were classified and the areas in which the boundary setting was incorrect and in which the image itself was determined to have a problem were identified as the priority update polygons that should be checked by operators.

Background: The completeness of cancer registration is a major validity index of any reported cancer incidence. The present study aimed to evaluate the esophageal cancer incidence registered in the Tehran Metropolitan Area Cancer Registry. Materials and methods: The data on esophageal cancer abstracted from three sources of 1) pathology departments, 2) medical records, and 3) death certificates during 2003 till 2007 were utilized. The completeness of the data sources were evaluated using coverage (defined as the proportion of a community population with esophageal cancer identified by the source) and density (defined as the proportion of non-empty fields of the data by source). Results: A total 1,404 cases of esophageal cancer were reported for the duration of the study. Pathology provided 771, medical records 432, and death certificates 609. The coverage was 0.55 for pathology, 0.31 for medical records, and 0.43 for death certificates. The respective density values were 0.82, 0.96 and 0.98, respectively. Pathology (0.45) was the most complete source followed by medical records (0.42), and death certificates (0.29). Discussion: A low degree of completeness dictates putting more effort into case finding plus abstracting data more thoroughly.

Wide-Area Differential Global Positioning System (WADGPS) is a system that operates a number of reference stations to provide correction information to improve the accuracy of GPS users, and it is available to service users within the area where the wide-area reference stations are installed. Recently, as positioning information has been used in various applications, the need for WADGPS for precise navigation in long-distance spaced areas where the wide-area reference stations cannot be installed has been raised. This paper tested the user navigation performance outside the wide-area reference stations of the WADGPS system, which serves both GPS Precise Positioning Service (PPS) and Standard Positioning Service (SPS) users. Static and dynamic tests were conducted using vehicles, and as a result, position accuracy improvement through WADGPS was confirmed even at points hundreds of kilometers outside the network area of the wide-area reference stations. Through this, the performance of the PPS/SPS correction system and the possibility of expanding the service area were confirmed.

Wide-Area Differential Global Positioning System (WADGPS) is a system that operates a number of reference stations to provide correction information to improve the accuracy of GPS users, and it is available to service users within the area where the wide-area reference stations are installed. Recently, as positioning information has been used in various applications, the need for WADGPS for precise navigation in long-distance spaced areas where the wide-area reference stations cannot be installed has been raised. This paper tested the user navigation performance outside the wide-area reference stations of the WADGPS system, which serves both GPS Precise Positioning Service (PPS) and Standard Positioning Service (SPS) users. Static and dynamic tests were conducted using vehicles, and as a result, position accuracy improvement through WADGPS was confirmed even at points hundreds of kilometers outside the network area of the wide-area reference stations. Through this, the performance of the PPS/SPS correction system and the possibility of expanding the service area were confirmed.

본 논문에서는 Passive RFID system으로 구성된 Smart Floor 환경에서 다 개체 로봇의 효율적인 영역 탐색 방법을 제안한다. 연구에서 사용된 Passive RFID system 은 RF 안테나의 인식 범위 내에 있는 RF 태그에 사용자가 원하는 정보를 저장하고 읽을 수 있다. 본 연구에서는 명시적인 위치정보를 저장한 RF 태그를 바닥에 매설한 Smart Floor 라는 환경을 구축하였고, 로봇에 설치되어 있는 안테나를 통하여 태그로부터 받아들인 위치정보를 논문에서 제안하는 방법으로 가공하여 모바일 로봇의 위치를 추정함과 동시에 Smart Floor 내의 다른 로봇에게 자신의 이동 흔적을 남김으로써 기존 탐색 기법에 비해 전체 영역 탐색 시간을 단축하여 효율을 높였다. 본 논문에서는 Smart Floor 환경을 활용하여 모바일 로봇의 효율적인 이동 알고리즘을 제안한다.

This paper proposes an enhanced fast scanning method for multi-agent robot system. Passive RFID tag can read and store the information within the range of recognizable RF tag reader. Based on this information of Passive RFID tag, the position of mobile robot can be estimated and at the same time, the efficiency of scanning process can be improved because it provides a scanning trace for other mobile robots. This paper proposes an dfficient motion planning algorithm for mobile robots in a smart floor environment.

Average throughput estimation of EV-DO forward link is implemented on the basis of the serving coverage area per sector instead of time consuming and complicated Monte Carlo simulation. For the implementation of this analysis function in cell planning tool, $CellTREK^{(R)}$, developed by KT, both SNR vs. DRC mapping table and receiver sensitivity are suggested as the satisfying criteria to be satisfied above each threshold level simultaneously.

작물 생육 진단에 있어서 군락 엽면적과 군락 피복은 주한 요소 이다. 최근에는 이러한 측정을 디지털 카메라를 활용하여 RGB 식생지수로작물 생육을 측정하고 있다. 본 연구는 밀 재배 기간 카메라의 노출 값을 다르게 설정하여 RGB 컬러 식생 지수와 군락 엽면적지수 및 군락피복에대해 평가하였다. 군락 엽면적, 군락 피복 및 디지털 영상 측정은 출수 16일전부터 출수 후 25일까지 하였다. 일출 후 30분 이내에 촬영하였다. 노출 값은 셔터 속도를3 수준(1/60s, 1/340s, 1/640s)으로 하였다. RGB 컬러 식생지수 분석은 파이썬으로 하였다. 실제 군락 엽면적과 군락피복간에는 정의 상관관계(r2 =0.94)를 보였다. 군락 피복 이미지의 ExG, GLI, NGRDI, ExG-ExR, MExG, TGI, MNGRD 및 MExG-CIVE는군락 엽면적 지수와 및 군락 피복과는 정의 상관관계를 보였다. 그러나 CIVE와 ExR은 부의 상관관계를 보였다. 본 연구 결과 1/640s 가 1/60s와1/320s에 비하여 노출이 높게 설정된 것으로 보였다. 또한, 토양과 녹색 영역을 분리하는데 있어서 너무 어린 시기 보다는 출수 전이 가장 잘분리되었다. 따라서 야외에서의 다양한 광 조건에서는 과도한 노출보다는 광 간섭을 줄이는 기술과 함께 작물의 생육 시기와 기상환경을 고려하여노출 값이 설정되어야 할 것이다.

The leaf area and canopy coverage were important factor for crop production. In recent years, these measurements have been used in digital cameras to measure crop growth as an RGB vegetation index. In this study, the correlation of the RGB vegetation indexes, leaf area index (LAI), and canopy cover light interception (CCLI) were evaluated by setting the appropriate exposure value of the camera during the wheat cultivation period. Leaf area index, canopy cover light interception, and digital camera measurements were performed. It was taken within 30 minutes after the sunrise. The exposure value was performed at 3 levels (1/60s, 1/340s, 1/640s). RGB vegetation indexes analysis was performed in Python. The correlation (r2=0.94) was shown between the leaf area index and canopy cover light interception. EXG, GLI, NGRDI, EXG-EXR, MEXG, TGI, MNGRD, and MeXG-CIVE of canopy coverage images were positive correlated with leaf area index and canopy cover light interception. However, CIVE and EXR showed negative relationships between the leaf area index and canopy cover light interception. As a result of this study, the 1/640s was higher than 1/60s and 1/320s in exposure value. During the separation between the soil and the green ground, the exit was not too young, but the best separation before heading time. These results showed that the exposure value must be set in consideration of the technology that reduces light interference instead of excessive exposure, taking into account the growing stage and weather environment of the crop.

From the review of Korean arbitration systems with the comparison of those of other countries, we can summarize some issues to be tackled as follows: First, Korean arbitration system started with the purpose of export promotion. This may be the main reason that various domestic disputes have not been resolved by arbitration. Second, the Korean Arbitration Law applies to private disputes. The Law's arbitration scope is wider than that of China and France, but narrower than that of the U.S.A. that encompasses a variety of disputes in the filed of consumer, labor, medical services, patents, etc. Third, active judges or public officials in Korea can not be arbitrator and there is no arbitration court. However, if chief judge allows the necessity, court's judges in the UK can be arbitrator with the mutual agreement of the parties and also arbitration system is operated in the court. Fourth, the Korean Commercial Arbitration Board(KCAB), the only representative institution for arbitration in Korea, is under the Ministry of Knowledge Economy(MKE). This makes it difficult for the KCAB to handle other disputes related to the Ministry of Health and Welfare, the Ministry of Strategy and Finance, the Ministry for Food, Agriculture, Forestry and Fisheries, the Ministry of Employment and Labor, etc. Fifth, as mentioned, the KCAB is the unique institution for arbitration by the Law in Korea, while other countries allow have a diversity of arbitration agencies such as maritime arbitration organization, consumer arbitration institution, arbitration court, etc. Therefore, we suggest some ideas to expand the arbitration's area of coverage in Korea as follows: First, there should be more active policies that promote various domestic disputes to be settled by the arbitration system. Second, it is quite needed to expand the scope of arbitration to cover many disputes in the fields of consumer, labor, medical service, advertising, fair trade, etc. Third, there should be discussions to allow court judges as arbitrator and to introduce the arbitration court. Fourth, the KCAB should strengthen its status and roles as general arbitration organization to overcome the limited scope of commercial disputes. For this, there should be the strong support and coordination among the MKE and other government agencies. Fifth, to reduce the burden of the court's complicated and expensive procedures, more efficient disputes resolution systems should be established on the basis of the parties' free will. Each central government agency should streamline the legal barriers to allow industrial organizations under its control to establish their own or joint arbitration system with the KCAB.

전 세계적인 코로나19 팬데믹의 이슈화로 인해 마스크, 손소독제 등 방역물품의 수요가 기하급수적으로 증가하며 방역물품 비축의 필요성 및 중요성이 증가하는 추세이다. 현재 국내에서 운영하는 물류센터는 대표적으로 파주와 함양 두 곳이 있으나 비축물량 부족, 이동시간 증가 등의 문제가 발생하는 상황이며 물류센터 입지, 도로 접근성 및 운송 효율성 고려, 비축량 확대 등의 대안이 필요할 것으로 예상된다. 본 연구의 목적은 상향식 관점의 이용자 설문조사, 웹크롤링 분석방법 등을 도입해 방역물품의 비축거점 접근성, 커버리지 분석결과 및 정책방안의 수용성을 도출하는 것이다. 전국 시⋅도(세종특별자치시 및 제주특별자치도 제외) 내 가용 가능한 고속도로 IC/JCT 교통광장 주변의 유휴부지와 전국에 분포하는 물류단지 가운데 분양률이 100%에 미치지 못해 유휴부지가 발생하는 물류단지를 중심으로 부지 현황 및 활용 가능성을 검토⋅분석하였으며, 다음(DAUM) 카카오맵 로드뷰, 스카이뷰(항공 사진), 면적툴 기능을 활용해 유휴부지 전수조사 후 사업대상지 내 이면도로 존재 여부에 따라 단기 및 중장기 사업으로분류하고 비축거점의 분산배치를 통한 접근성, 비축거점의 면적 및 비축가능량 등의 분석결과를 도출하였다. 향후 방역물품의 비축거점을 마련하는 경우, 「국토의 계획 및 이용에 관한 법률」, 「국토의 계획 및 이용에 관한 법률 시행령」 등에 의거 고속도로IC/JCT 교통광장 유휴부지 내 단순 창고는 건축이 가능하므로 방역물품 비축창고의 구축을 위한 법률의 신설⋅개정의 필요성은낮을 것으로 예상된다. 그러나, 국공유지 활용에 대한 국가 지원 및 협조 등의 추가적 방안 모색과 분석적 측면에서 유휴부지의현장조사를 보완하여 실제 활용가능한 부지 선정 및 면적 도출의 추가 연구가 필요하고 커버리지 개선을 위해 향후 방역물품의비축거점 대상지를 확대⋅구축하여 접근성을 확보하는 중장기적 물류정책의 패러다임 전환이 필요할 것으로 보인다.

Due to the global issue of COVID-19 Pandemic, the demand for quarantine supplies such as masks and hand sanitizers is increasing exponentially, and the necessity and importance of stockpiling quarantine supplies are increasing. Currently, two logistics centers operated in Korea are in Paju and Hamyang, causing problems such as a shortage of stockpiles and an increase in travel time, and alternatives such as location of the logistics center, road accessibility and transportation efficiency, and expansion of stockpiles are expected. The purpose of this study is to perform an analysis related to the stockpile base based on the analysis results of the bottom-up user survey and to derive the accessibility of the stockpile base, coverage analysis results, and acceptability of policy measures. Among the idle sites around IC/JCT transportation squares available in cities and provinces across the country (excluding Sejong and Jeju), the site status and availability were reviewed and analyzed. After using the DAUM Kakao Map road view, sky view (airport photo), and area tool functions, it was classified as a short-term and mid- to long-term business depending on the existence of a back road in the project target site, and the analysis results were derived. In the future, when establishing a stockpiling base for quarantine supplies, simple warehouses in idle sites of IC/JCT transportation plaza on highways can be built under the National Land Planning and Utilization Act and the Enforcement Decree of the National Land Planning and Utilization Act, so the need to establish or revise laws to build quarantine supplies is expected to be low. However, it is necessary to find additional measures such as state support and cooperation in the use of national and public maintenance, conduct on-site surveys on idle sites to select and derive areas, and shift the paradigm of mid- to long-term logistics policies to expand and build targets in the future to improve coverage.

This study was to examine the effects of insurance coverage on the utilization of public health institutions and to identify the factors associated with the utilization. The data were obtained from household interview surveys conducted twice in Hwachun Gun, Kangwon Do. The time period covered in the first survey was December $17{\sim}31$, 1987, before the implementation of regional medical insurance for the self-employed, and that of the second survey was January 28 $\sim$ Febuary 11, 1990, after its implementation. Major findings emerged from the analysis can be summarized as follows (1) Medical care utilization of rural people markedly increased after they were covered by medical insurance. The insurance coverage increased the utilization of public health institutions as well, and this increase was mainly attributable to the utilization by chronically ill patients. (2) Between 1987 and 1990, the proportion of the utilization of public health institutions over whole medical care utilization decreased. But the proportion increased for chronically ill patients covered by regional medical insurance during the same time span. (3) The results of logistic regression suggested that the rural self-employed utilized public health institutions at an increased rate after they were covered by medical insurance. It was also indicated that the increase resulted from the utilization by chronically ill patients. (4) The relative importance of public health institutions for rural medical care decreased after the implementation of regional medical insurance. But considering that the utilization of public health institutions by chronically ill patients increased after insurance coverage, attention should be directed to improving the capability of public health institutions to control chronic degenerative diseases.

The purpose of this paper is to identify how the broadcast media has played an important role on the process that the “Gangnam Area” has had some symbolic significance as of today. This paper identifies the fact that the “Gangnam Area” has facilitated the ‘problematic establishment’ associated with various social relationships, as it is located in the heart of Korean capitalism. For this research, discourse analysis and content analysis have been performed on texts related with “Gangnam Area” in the KBS(Korea Broadcasting System) TV news coverages. Firstly, this paper indicates that the KBS news covering the “Gangnam Area” deals mainly with the matters of ‘real estate’ and ‘education-oriented’ that form major conflict ground between the central government and residents including enterprises related. Accordingly, it has been discovered that “Gangnam Area” facilitates the setup of problems associated with various social relationships in the Korean society due to the positive governmental involvement. It was elucidated that such conflict had different features from existing social conflict structures. Secondly, Analysis on central discourses as each aspect of affairs on “Gangnam Area” in KBS-TV news coverages indicated that ‘discourse focused on buildup of economicㆍcultural capital’ was prominent from 2000 to 2002 and then ‘Discourse centered on interzonal distinction’ was distinguished from 2003 to 2004. In 2005, intense competition in internal order as rank consolidated ‘discourse of Invincible Gangnam.’ Moreover, it is assumed that KBS-TV news coverages concentrated on delivering detached facts rather than sticked to their critical standpoint. Consequently such KBS’s coverage pattern resulted in construction of discourses as of today. In conclusion, KBS-TV news handles the daily lives of “Gangnam area” by using the usual and superficial reporting method, which induced “Gangnam area”, as the specific space to gain the symbolic meaning. It is found out that the meaning of “Gangnam area” is fixed as the symbol of “Rich neighborhood” or “invincibility myth of Gang-nam area” is always realized and also exercises the symbol of power in real life.