Earticle

We developed a filling seal ring packing machine and carried out the conveying distance and container airtightness tests, and obtained the following results. As a result of testing whether the packaging paper is within 25mm of conveying distance and whether it is suitable for achieving the goal, the prototype with the target feeding distance of 23mm was shortened to 16.4mm for the right pavement line and 20.4mm for the left line, saving 80% compared to the existing one. As a result of the test of the automatic packaging machine for filling and sealing the air tightness of the container, it was confirmed that the air tightness was 100% maintained.

인코텀즈 2010의 11가지 거래조건에 대한 연구는 계속해서 축적되어 오고 있다. 최근 무역거래실무의 특징들을 고려해보면, 공산품(제조품)거래의 경우 매도인의 공장에서 매수인의 공장까지 복합운송의 형태로 화물이 운반되고 있음을 알 수 있다. 그러나 학계에서 이들 복합운송 조건에 대한 연구는 미진한 편이다. 더욱이 매도인과 매수인의 최대 의무가 부여되는 DDP조건과 EXW조건에 관한 연구는 거의 이루어지지 않고 있다. 그러나 door to door 서비스의 일관 서비스(one stop service)의 확대로 이들 극단의 거래조건들의 사용이 증가하고 있다. EU와 같은 Trade Bloc에서만 사용되는 국내조건으로 알려져 있으나 인코텀즈 2010 개정 후 국제거래에도 사용가능함을 명시하였고, 기계, 원목 등의 거래에서 많이 사용되는 조건으로 그 연구가 필요한 시점이다. 이에 본 연구는 인코텀즈 2010의 공장인도조건(Ex Works: EXW)의 실무적 쟁점에 대해서 고찰하였다. 또한 공장인도조건의 실무적 쟁점을 5가지로 구분하여 제시하였다.

The studies related to 11 trade terms in Incoterms 2010 have been accumulated well. However, there are many studies focusing on FOB and CIF terms, which are most used in international trade, and studies on characteristics and changes of each trade term have been mainly conducted before and after the amendment of Incoterms, which is revised every 10 years. However, considering recent trade features, the expansion of multimodal transport transactions is expected to increase the use of multimodal transport terms represented as all modes of transport in Incoterms 2010. However, researches on these multimodal transportation terms in the academia are rather limited. Furthermore, little research has been conducted on the DDP and EXW terms, which give the seller and buyer the maximum obligation respectively. However, due to the expansion of one stop service based on the door to door service, the use of these trade terms is recently increasing. Therefore, this study examined the practical issues of EXW terms in Incoterms 2010. It is known as the domestic trade terms used only in Trade Bloc like the EU, but it is stated that it can be used for international transactions after Incoterms 2010 revision. So, this study divides the practical issues of EXW into five categories and also suggests some advices to trade parties.

역공학(Reverse Engineering) 기술이 진보함에 따라 컴퓨터 소프트웨어에 대한 불법 조작 및 변조 등의 위협이 증가하고 있으며, 인터넷에 공개된 단순한 도구를 이용하여 누구나 쉽게 크래킹(Cracking)을 할 수 있게 되었다. 자사의 소프트웨어를 위협으로부터 방어하고자 하는 제작사들의 노력과 이를 무력화시키고자 하는 소위 크래커들의 노력은 지금까지도 계속되고 있다. 이에 본 논문에서는 소프트웨어가 가지는 위협 모델과 크래킹 기술에 대해 분석 및 실험하고, 소프트웨어를 위협으로부터 보호하기 위한 윈도우 환경에서의 메모리 해킹 방지 시스템을 제안한다.

Recently, illegal manipulation and forgery threats on computer softwares are increasing due to the advances in reverse engineering techniques. Furthermore someone who has concerns about these area can crack the software by using the open-to-public simple tools on the internet. The software companies are struggling to defend their own softwares against threats, while the crackers are continuing to crack the softwares. In this paper, we first establish the generic software threat model and, analyze and experiment on the software cracks, before suggest a memory hacking prevention system in Microsoft Windows environment.

최근 스마트팩토리와 같은 자동화 기술이 발전함에 따라 24시간 운용 가능한 물류 시스템에 대한 요구가 늘어나고 있다. 기존의 인력에 의존한 적재방식과 달리 로봇 기반의 적재 시스템은 화물의 크기나 형태에 따라 유동적인 배치가 어렵기 때문에 적재 공간의 효율적 이용에 한계가 존재한다. 따라서 본 논문에서는 향후 보편화될 로봇 기반의 적재 시스템에 적합한 화물 관리 방식 및 최적화 알고리즘을 제안한다. 제안하는 시스템은 고속 검색 및 효율적 관리를 위 한 Heap 구조기반 화물 관리 방식과 공간 효율을 극대화하기 위한 그리드기반 적재 최적화 알고리즘을 포함한다. 일 반적으로 택배화물은 우선순위 큐와 같이 선입선출 구조를 가지며 동시에 화물의 입출고로 인해 화물 데이터베이스의 가변성이 높다. 따라서 Heap 구조를 통해 화물 데이터베이스를 구축하여 효율성을 높인다.

The molding process can be divided into five separate steps: plastification, injection, holding, cooling, and finally ejection. In the plastic injection molding, the effect factor such as mold temperature, injection speed, packing pressure and inhomogeneous cooling under packing process affects both the article dimension and physical characteristics. Especially, the packing pressure is the most critical factor to affect molded articles quality among the packing parameters. In this paper, the CAE simulation considering the molding condition is performed to predict the faulty cause which appears in the packing process between cavities of injection molding machine. From the results of CAE simulation, the packing phenomena according to the product form and the gate position was investigated to improve the article quality and minimize the various molding defects. The effect of packing pressure and gate number on the injection molding was discussed.

A conventional packing ring was designed with a large clearance to prevent damage due to the vibration of the rotor, which can lead to an increase in steam leakage. In this study, a flexible packing ring using winding springs was developed to prevent damage to the rotor teeth by minimizing vibration, while maintaining a smaller clearance than that of conventional rotor designs. Theoretical analysis and finite element analysis (FEA) were used to design the winding spring to satisfy the specified allowable stress limit and minimum load requirements. The shape of the winding spring was designed by applying curves to the center and end parts of a flat spring. Computational fluid dynamics (CFD) analysis was used to predict the leakage of the flexible packing ring. Flow rate measurement tests were performed to verify the leakage reduction efficiency and the reliability of the CFD analysis.

Performances of urethane packing in the hydraulic breaker were analyzed using a finite element method. Because of high temperature and high pressure in the hydraulic breaker, it is better to use urethane rather than rubber as a packing material. We obtained the physical properties of urethane at elevated temperature by the tensile test. We analyzed buffer seal and U-packing maintaining the pressure and preventing oil leakage. Deformation, stress distribution, contact length, contact pressure of packing at each pressure step were obtained using finite element analysis. As the temperature increases, stress and contact force tend to decrease at low pressure. As the gap between piston and cylinder increases, contact length and contact forces decrease. Consequently, it is possible to design the packing section using these analyses, and construct a system to predict the possibility of oil leakage in the hydraulic breaker.

Rapid Prototyping has made a drastic change in all industries which needs to reduce the time for the development of new products. Orientation and packing in rapid prototyping is considered as the most important factors to maximize the utilization of space in the build chamber and reduce build time. However, the decision of these parameter is mainly dependant on the operators's experience. This paper presents the methodology to find the optimal build layout considering an orientation and packing of multiple parts in SLS processing. Each part is represented as a voxel structure to deal with the inefficiency in a bounding box approach. Test results show that the adapted BL algorithm with a genetic algorithm(GA) can be applicable to a real industry.

Purpose: The aim of this study was to provide a scientific basis for shelf life and re-establish the shelf life in a hospital environment by investigating the validity periods of various packaging materials. Methods: We selected six departments to store sterilized items, prepared 482 sterilized items, and stored them for 12 months. Each sample was tested using a microbiological culture in the laboratory every two weeks. When the result was positive, the sample was considered contaminated. The temperature and relative humidity were measured using an automatic control system to investigate the storage environment during the study period. Results: Except for two samples, which were positive in the 22nd and 28th weeks, 480 samples were negative. The temperature and relative humidity of the sample storage area were measured every week. The annual average temperature was 23.6±1.6℃, and the mean relative humidity was 35.1±15.2%. The cabinets used in this study were the two-open and four-closed types. Conclusion: This study confirmed the validity of the expiration date in a hospital environment. Based on the results, the nonwoven fabric remained sterile for more than nine months. No case of contamination of the paper-plastic pouch packaging was observed, owing to the microbial culture for two months.

다수 무인기를 이용한 시스템은 정찰, 네트워킹, 항공 촬영 등 다양한 목적으로 활용되고 있다. 이러한 시스템에서 다수 무인기로 구성된 대형을 형성하고 유지하는 것은 필수적이다. 본 논문에서는 다수 무인기의 대형을 형성하기 위한 자율화된 분산형 제어를 수행하는 알고리즘을 제안하였다. 제어명령은 근접 무인기 또는 임무 영역으로부터 서로 밀어내는 방향으로 작용하는 2차 시스템 형태의 힘을 고려하였다. 제어명령은 외부의 개입 없이 계측과 통신으로부터 획득되는 상대위치/속도를 통해 계산된다. 이는 개별 무인기들이 기준거리를 추종하도록 하며 임무영역 안에 겹치지 않고 최대한 조밀하게 배치되도록 한다. 기준거리 결정에는 채우기 문제를 풀기 위한 최적화 기법과 유사한 방식을 적용하였다. 임무영역은 형성하고자 하는 대형의 외곽선으로 정의되며 임무에 따라 유동적으로 설정될 수 있다. 제안한 알고리즘의 성능을 확인하기 위하여 수치 시뮬레이션을 수행하였다. 복잡성과 확장성을 고려한 영역에서 약 26.94초에 대형이 형성되며 약 71.91%의 채우기 밀도를 가지는 것을 확인하였다.

Multiple UAV System has been used for various purposes such as reconnaissance, networking and aerial photography. In such systems, it is essential to form and maintain the formation of multiple UAVs. This paper proposes the algorithm that produces an autonomous distributed control for each vehicle for a flexible formation. This command is a repulsive force in the form of the second-order system by the nearest UAV or mission area. The algorithm uses the relative position/speed through sensing and communication for calculating the command without external intervention. The command allows each UAV to follow the reference distance and fill the mission area as densely as possible without overlapping. We determine the reference distance via optimization technique solving the packing problem. The mission area comprises the desired formation outline and can be set flexibly depending on the mission. Numerical simulation is carried out to verify the performance of the proposed algorithm under a complex and flexible environment. The formation is formed in 26.94 seconds and has a packing density of 71.91%.

PURPOSES : In this paper, the packing degrees of binary granular mixtures under vibration compaction were simulated by using DEM with spherical particles to evaluate the applicability of the DEM for aggregate packing degree estimation. METHODS : The packing degrees of fine particles, coarse particles, and their mixture with different fine particle fractions were evaluated in DEM simulation for given various material property conditions. In order to check the validity of estimated packing degrees of particle mixtures, analytical model such as Furnas model that is capable of considering wall effect and loosening effect. RESULTS : DEM with spherical particles showed good agrement with analytical solution in terms of the packing degrees of binary granular mixtures with various fine particle fractions for most of conditions. Also, it was found that not the vibration amplitude but the ratio of particle diameter with vibration amplitude should be considered to explain the susceptibility of particle packing degree with vibration amplitude for the same acceleration condition and that the reduction in elastic modulus to shorten computational simulation time should be carefully considered when the packing degree is the most important concern. CONCLUSIONS :It was concluded that DEM with spherical particles are good enough to estimate the packing degree of binary granular particles for most of conditions. However, the effect of inter-particle frictions between fine and coarse particles have to be studied further in order to clarify the issue relating poor predictions for high inter-particle friction conditions.

The main purpose of this study is to seek desalinization effect of subsurface drainage system with rice hull packing in Dae-Ho Reclaimed Land. After 4 years installed sub-surface drainage system, distribution of drained water electric conductivity (ECw) was 4.43~12.78 ds/m. The soil profile showed partial development of the soil structure and compaction of subsoils with increased bulk density. The bulk density of the subsoil was 1.42~1.66 g/cm$^3$, which might limit root growth. The soil color changed near the drainage pipe line. Distribution of soil extract solution ECe and SAR as subsurface drainage pipe position and drainage canal distance showed desalinization effect of subsurface drainage system with rice hull packing as widening effective zone of subsurface drainage pipe.

Wasted meat & bone has generated as byproducts in the slaughtering process of livestock and also faced with demands for its recycling and environmental protection. Many studies have been conducted to recycle byproducts and carried out mainly on the crushing of bones and the vacuum packing technology of products. In this study, the crushing unit, transporting unit, separated unit and packing unit have designed for development of the crushing and packing systems. Also, to confirm the performance of this system, the experimental verification were carried out the working noise and packing weight.

본 연구는 임도의 포장재로 사용할 수 있는 다공성 실리카를 이용한 친환경 고화재 의 환경성을 검증하기 위해 pH특성 시험과 용출 시험, 어독성 시험을 수행하였다. pH 특성 시험결과, 친환경 고화재 혼합토의 경우 점토는 pH 7.09, 유기질토는 pH 6.67, 그 리고 풍화토는 pH 7.15로 나타났으며, 시멘트 혼합토의 경우 점토는 pH 9.82, 유기질토 는 pH 9.15, 그리고 풍화토는 pH 9.35로 나타나 고화재 혼합토가 시멘트 혼합토 보다 pH값이 다소 낮게 나타났으며, 또한 용출 시험에서는 Pb이 0.04mg/ℓ, CN이 0.004mg/ ℓ로 소량이 검출되었으나 Cd, Cu, Fg, Cr6+, As, org.P의 기타 항목에서는 검출되지 않 아 모든 항목이 유해폐기물 기준치를 초과하지 않는 것으로 나타났다. 어독성 시험결과 는 초기 24시간 내 시멘트의 경우 공시어가 모두 치사한 반면 친환경 고화재의 경우는 치사율이 0%로 나타났다. 이와 같이 모든 유해성 시험에서 친환경 고화재가 시멘트보 다 유해성이 적은 것으로 나타났다.

In this study, to verify the environmental property of eco-friendly solidification material using porous silica in forest road, a pH property test, solubility test, and fish toxicity test have been performed. As a result of pH property test, mixed soil of eco-friendly solidification material showed pH of 7.09 from clay, pH of 6.67 from organic soil, and pH of 7.15 from weathered soil, and in case of cement mixed soil, clay showed pH of 9.82, organic soil showed pH of 9.15, and weathered soil showed pH of 9.35, showing mixed soil of solidification material to have lower pH value than cement mixed soil. In the solubility test, 0.04mg/ℓ of lead and 0.004mg/ℓ of CN were found, but Cd, Cu, Fg, Cr6+, As, and org.P were not found to show that all of them do not exceed the standards of hazardous waste. In the fish toxicity test, within the initial 24 hours, all fish died from cement, while no fish died from eco-friendly solidification material. Likewise, in all hazardousness tests, eco-friendly solidification material showed lower hazardousness than cement.

신발이나 의류 등에 부착되는 라벨(label)은 먼저 고정 개수의 라벨이 배치된 템플릿(template)을 제작한 후 각각의 템플릿을 필요한 수량만큼 인쇄하여 생산한다. 이때 템플릿 내의 레이블 조합 방법에 따라 불필요한 초과생산이 발생하게 된다. 본 논문에서는 이 과정을 하나의 최적화 문제로 정형화하고, NP-hard임을 증명한 후, 의사 다항시간(pseudo-polynomial time)의 근사(approximation) 알고리즘을 제시한다. 알고리즘은 기본적으로 탐욕적(greedy) 기법을 따르며 알고리즘의 각 단계에서 동적 계획법(dynamic programming)을 이용한다. 다양한 실험 데이터를 통해 제시한 알고리즘의 성능을 평가하였다.

Labels of clothes or shoes are produced by making templates containing a fixed number of labels of different types and printing them multiple times. The composition of label types in templates determines the production loss which is defined to be the over-produced quantities. In this paper, we formulate this into an optimization problem and prove its NP-hardness. Then we present a pseudo-polynomial time approximation algorithm. Our algorithm takes a greedy approach and each step of it solves a sub-problem using dynamic programming technique. We tested the algorithm for a variety of sample data and analysed its performance.