In this study, the initial operation characteristics of a multi-type cooling system with three indoor units using an inverter compressor were investigated experimentally using a calorimeter. The operating characteristics of the cooling system were confirmed under the full load condition of simultaneous operation of three rooms and the partial load condition of individual operation of two or one room under the standard cooling conditions. The capacities of A, B and C are 50, 20, and 30% of the total capacity, respectively. The 3 room combination has 100% capacity, the 2 room combination has 50, 70 and 80% capacity, and the 1 room has 20, 30, and 50% capacity. The compressor condensing and evaporating pressures, the electronic expansion valve openings of indoor units A, B, and C, and the compressor operating frequencies were measured for 10 minutes after the cooling system was started. During the initial operation, the changes in the operating time and opening of the electronic expansion valve varied depending on the indoor unit combination and the operating load, and the relationship between the compressor pressure and the operating frequency was found.

As the number of enlistees decreases due to social changes like declining birth rates, it is necessary to conduct research on the appropriate recalculation of the force that considers the future defense sufficiency and sustainability of the Army. However, existing research has primarily focused on qualitative studies based on comprehensive evaluations and expert opinions, lacking consideration of sustained support activities. Due to these limitations, there is a high possibility of differing opinions depending on perspectives and changes over time. In this study, we propose a quantitative method to calculate the proper personnel by applying system dynamics. For this purpose, we consider a standing army that can ensure the sufficiency of defense between battles over time as an adequate force and use battle damage calculated by wargame simulation as input data. The output data is the number of troops required to support activities, taking into account maintenance time, complexity, and difficulty. This study is the first quantitative attempt to calculate the appropriate standing army to keep the defense sufficiency of the ROK Army in 2040, and it is expected to serve as a cornerstone for adding logical and rational diversity to the qualitative force calculation studies that have been conducted so far.

By the recent fast growth of e-commerce markets, it has been stimulated to study order picking systems to improve their efficiency in distribution centers. Many companies and researchers have been developed various types of order picking systems and pursued the corresponding optimal operation policies. However, the performances of the systems with the optimal policies often depend on the structures of the centers and the operation environments. Based on a simulation model that mimics a unique zone picking system operated by a real company in the Republic of Korea, this study compares several operation policies and finds the most appropriate order selection rule and worker assignment policy for the system. Under all scenarios considered in this study, simulation results show that it is recommendable to assign more efficient workers to the zones with heavier workload. It also shows that selecting the order with the maximum number of non-repeatedly visited zones from the order list provides the most consistent and stable performances with respect to flow time, makespan, and utilization of the system even under the scenario with the breakdown zones. On the other hand, selecting the order with the minimum ratio of penalty to the number of zones performs the worst in all scenarios considered.

감사청구제도는 감사를 통해 국민 권익을 보호하기 위한 제도이다. 이 러한 감사를 통해 공공부문의 도덕적 해이나 부정 등에 관한 사항을 적 발하게 되면서 감사의 역할과 기능에 대한 관심이 고조되고 있다. 특히, 감사에 의해 공공기관의 책임행정을 구현한다는 목적에 따라 감사의 의 미는 더욱 중요해지고 있다. 그러나 국민의 신문고로서 역향을 수행할 것으로 기대하고 있는 감사청구제도에서 본 연구의 목적은 국민감사청구 제도와 공익감사청구제도 간 제도적 통합에 관한 근거를 제시하는 것이 다. 물론 기존 연구에서 두 제도 간 통합에 관한 제언을 하였으나 그에 대한 구체적 근거가 부족하고 원활한 감사청구제도를 위해 본 연구가 진 행되었다. 통합에 대한 논리적 근거로서 절차집행의 우선성, 법률적용의 확장성, 제도운용의 적절성을 제시하였다. 즉, 국민감사청구와 공익감사 청구가 운영 법률이 상이하긴 하나, 실제로 동일한 기능을 수행하고 있 고 청구인의 기준 및 청구대상 요건이 유사하다는 점이다. 또한 운영현 황에 있어 국민감사청구제도보다 공익감사청구제도가 상대적으로 원활하 게 운영되고 있다는 점이다.

We analyzed risk factors of coastal gillnet fishers during fishing process and considered work safety measures to reduce safety accidents during fishing using a UWB (ultra wideband) based positioning system. The static position accuracy of the UWB based positioning system was 45 cm. When entering a port, there is a risk of falling overboard. When casting a net, there was a risk of falling overboard due to being hit by fishing gear or guards, or getting caught in a buoy line or sinker line. When hauling a net, there is a risk of getting caught between fishing gear and net hauler, and the risk of musculoskeletal disorders due to repetitive work over a long period of time. Most safety accidents during work on fishing boats are blamed on human errors of the fisher and skipper, but safety accidents occur due to a mixture of mechanical and equipment factors, work and environmental factors, and management factors in addition to human errors. Therefore, the 4E were presented as countermeasures against the 4M, which are causes of safety accidents, and the proposed measures were used to identify risk factors for operation process, comply with work safety rules, and ensure the wearing of personal protective equipments. We need to reduce safety accidents during work by making it part of our daily routine. These research results can be used in the future for optimal placement of fishing gear and fishing nets in other coastal industries where safety accidents occur frequently.

The purpose of this study was to propose an operational concept for a ship in a fleet equipped with an interceptor missile system, a naval surface to air defense system, and to develop a simulation program that reflects it. The results of the defense activities of other ships in the fleet can be reflected by receiving information about the status of the enemy missiles. The allocation of defensive assets is based on the survival probability of the ship, not on the destruction of enemy attacks, which can be obtained as the product of the expected survival probability for each enemy missile. In addition, the concept of predicted survivability was introduced to assess the loss of future defense opportunities that would result from assigning a new command. A simulation program was also developed as a tool for realizing the proposed concept of operations, which generated cases.

PURPOSES : The number of snowfall and the amount of snowfall are gradually increasing, and due to the characteristics of Seoul, which has a lot of traffic, it is difficult to respond quickly with a snow removal method that relies on snow removal vehicles. Therefore, it is necessary to develop an IoT based eco-friendly snow removal system that can respond to unexpected heavy snow in winter. In this study, the low temperature operation and snow removal performance of the IoT road condition snow removal detector and the snow removal system using CNT and PCM are evaluated in the climatic environment chamber. METHODS : To make artificial snow, it consists of an climatic environment chamber that can simulate a low temperature environment and equipment that can supply compressed air and cold water. Depending on the usage characteristics of the climatic environment chamber, use an air-water type snow maker. In order to make artificial snow, wet temperature, which takes into account the actual air temperature and the amount of moisture in the air, acts as the most important variable and is suitable for making snow, below –1.5 ℃. The lower the water temperature, the easier it is to freeze, so the water source was continuously supplied at 0 ℃ to 4 ℃. One of the two different pipes is connected to the water tank to supply water, and the other pipe is connected to the compressor to supply high-pressure air. Water is dispersed by compressed air in the form of many small droplets. The sprayed microscopic water particles freeze quickly in the low temperature environmental climatic chamber air and naturally fall to the floor, forming snow. Based on the KS C IEC 60068-2-1 cold resistance test standard, an integrated environmental test procedure was prepared to apply to IoT-based snow removal systems and performance evaluation was performed accordingly. The IoT based eco-friendly snow removal system is needed to in winter, so visual check and inspect the operation at the climatic chamber before setting up it to the actual site. In addition, grid type equipment was manufactured for consistent and reliable snow removal performance evaluation under controlled environmental conditions. RESULTS : The IoT-based eco-friendly snow removal system normally carried out the task of acquiring data and images without damaging the appearance or freezing in a low temperature environment. It showed clear snow removal performance in areas where PCM and CNT heating technology were applied to the concrete slab. This experiment shows that normal snow removal tasks can be carried out in low temperature environments in winter. CONCLUSIONS : The integrated environmental test procedures and grid type evaluation equipment are applied to low temperature operation and snow removal performance evaluation of snow removal systems. In the climatic environment chamber, where low temperature environments can be simulated, artificial snow is created regardless of the season to derive quantitative experimental results on snow removal performance. PCM and CNT heating technology showed high snow removal performance. The system is expected to be applied to road site situations to preemptively respond to unexpected heavy snow in winter.

The need for an intelligent information-based ship accident prevention and control system for various marine accidents is very clearly emerging. As it is a variety of marine accidents, the causes are diverse. Therefore, it can be said that it is very important to prevent these marine accidents and their causes in advance. Therefore, a study was conducted on an intelligent information-based ship safety management decision support system that provides information necessary for decision-making at sea and land through an integrated management device for ships that informs safety-related risks in real-time ship operation. In the future, we intend to pursue the development of a system that can aim for safer and more economical ship operation by linking it to navigation instruments through the evaluation and analysis of AI, IoT, and big data.

In an automotive plant, an automated storage and retrieval system (ASRS) synchronizes material handling flows from a part production line to an auto-assembly line. The part production line transfers parts on small-/large-sized pallets. The products on pallets are temporarily stored on the ASRS, and the ASRS retrieves the products upon request from the auto-assembly line. Each ASRS aisle is equipped with narrow-/wide-width racks for two pallet sizes. An ASRS aisle with narrow-/wide-width racks improves both storage space utilization and crane utilization while requiring delicate ASRS aisle design, i.e., the locations of the narrow-/wide-width racks in an ASRS aisle, and proper operation policies affect the ASRS performance over demand fluctuations. We focus on operation policies involving a common storage zone using wide-width racks for two pallet sizes and a storage-retrieval job-change for a crane based on assembly-line batch size. We model a discrete-event simulation model and conduct extensive experiments to evaluate operation policies. The simulation results address the best ASRS aisle design and suggest the most effective operation policies for the aisle design.

자율운항선박(MASS : Maritime Autonomous Surface Ships)은, 고도의 자율도를 가지고, 계획된 경로를 따라 자율 운항하지만, 필요시 육상원격제어센터(SRCC : Shore Remote Control Center)에서 선박의 운항에 직접 개입할 수 있다. 본 연구에서는 이러한 자율운항 선박의 운항을 육상에서 모니터링하고 유사시 원격제어하는 역할을 담당할 육상원격제어사(SRCO : Shore Remote Control Officer)의 교육 훈련에 필요한 시뮬레이터 시스템의 운용개념과 이를 가능하게 하기 위한 요구기능에 대해 검토하였다. 육상원격제어 시뮬레이터 시 스템은, 다수의 자율운항선박의 운항상황을 모니터링하는 Monitoring Station, 유사시 특정 선박의 운항에 직접 원격개입하는 Control Station의 기능을 모의하도록 하였고, 시뮬레이션 종합통제실, 자율운항선박 운항상황 모의 시뮬레이터, 그리고 주변의 유인선 운항을 모의하기 위한 통항선 시뮬레이터 등으로 구성하였다. 기능적으로는, 육상에서 선박을 직접 제어하기 위하여 원격으로 개입하는 ESRC(Emergency Situation for Remote Control) 상황을 정의하여 이러한 상황을 모의할 수 있도록 하였다.

The development of technology related to the Fourth Industrial Revolution and the growth of the online market due to pandemic are continuing the growth of the logistics market for product delivery. If it is difficult to deliver the product directly to the customer during delivery, storage and delivery using the unmanned courier box are being carried out. However, existing storage boxes are not actively used due to lack of usability even though they have the advantage of storing goods and delivering non-face-to-face. In addition, existing courier boxes are not prepared for cold chain transportation. The unmanned delivery storage device with ICT cold chain technology should be developed to prepare for the transition to non-face-to-face society, to improve logistics efficiency and meet user's requirements. Also, it is necessary to consider the measures to reduce the safety problems that may occur during the use and maintenance of the automatic system.This study conducted a model-based analysis for the development of unmanned delivery storage devices with ICT cold chain technology, and conducted a study to derive the system development specifications that meet the requirements and secure safety and apply them to the development process.

This study tried to suggest a systematic improvement plan to prepare a civil safety insurance operation and management system by reviewing the operation and management status of civil safety insurance, which is operated and managed by each local government autonomously. In this study, the problems of the current civil safety insurance were analyzed by dividing them into the lack of systematic management of insurance items, overlapping coverage between insurance items, and deviations in compensation limits. As a systematic improvement plan, it was suggested to secure the systemic management of guarantee items, standardize compensation standards, prepare an integrated operation and management system, and provide financial support for local governments with poor financial independence. Since the problems and improvement plans for the civil safety insurance analyzed as described above are formed by exchanging and receiving a complex mutual influence, the institutional improvement plan for the operation and management system of the civil safety insurance is not only a specific part of the study, but also comprehensively current citizens. Based on the results derived from the analysis of safety insurance, it is concluded that alternatives must be found.

중국에는 파악 가능한 불학원이 60-70여 개 존재한다. 이 불학원들은 중등불학원 과 고등불학원으로 나눌 수 있는데, 본 논문에서는 이들 불학원에 대해 설립 및 운 영 현황과 학제 구성의 두 측면으로 나누어 고찰해보았다. 설립 및 운영의 측면으로 보면 독립형, 본교-분교형, 연합대학형이 있다. 독립형은 불학원 설립의 기본형에 속 하고, 본교-분교형에는 중국불학원과 그 분원들이 이에 속한다. 연합대학형에는 광둥 불학원, 저장불학원, 장쑤불학원 등이 이에 속한다. 학제 편성의 측면으로 보면 중전 (2년), 대전(3년), 예과(2년), 본과(4년), 연구생(3년)의 체계로 구성되어 있다. 여기에 남아 있는 초급불학원과 양정원(养正院)을 더해 7등급 체계로 이해할 수도 있다.

가석방은 수형자의 자발적인 개선을 유도함과 동시에 재범위험성이 없는 수형자를 조기에 사회에 복귀시키는 역할을 하지만 국민의 법감정 및 사회복귀 준비 정도 등 많은 요인에 의해 영향을 받는다. 우리나라의 가석방 제도는 1996년 개정된 이래 법 무부 가석방심사위원회에서 가석방심사를 하는 시스템으로 운영되고 있다. 하지만 가 석방 심사 제도는 그동안 많은 비판에 직면해 왔다. 본 논문의 주요 목적은 그동안 제기된 가석방과 관련한 쟁점에 대한 비판적 검토를 통해 현재 운영되고 있는 가석방 제도의 실질적인 문제점과 향후 발전방향을 모색하는 것이다. 그간 제기된 가석방 제 도와 관련한 주요 비판은 가석방 제도의 소극적 운영, 가석방 심사기준의 모호성, 가 석방심사 신청기관의 재량권 통제 장치 미흡, 가석방심사위원회 심사의 형식화에 대 한 우려로 나누어 볼 수 있었다. 하지만 이에 대한 비판적 검토를 통해 기존의 이러한 비판에 대응하여 법무부 교정본부 및 법무부 가석방심사위원회에서는 최근에 가석방 을 보다 확대하고 재범예측지표를 개발하는 등 많은 개선을 이루었음을 알 수 있었다. 그리고 주된 비판 중의 하나였던 법무부 가석방심사위원회에 의한 가석방 심사는 1996년 이전 각 기관 신청 방식의 문제점을 해결하기 위해 도입된 것이며 처음 도입 취지에 맞게 전국적으로 일관된 기준에 따라 가석방 심사가 이루어 질 수 있는 효율적인 제도라고 판단된다. 하지만 향후 가석방 제도 운영의 효율화를 위해 성인과 소년수형자 가석방의 일원화, 법무부 가석방심사위원회 확대, 가석방 요건으로 수용생활 태도 등의 비중 강화, 가석방 조건의 다양화와 사회적 처우 프로그램과의 연계, 가석방 기준 완화에 따른 재범률 증가에 대한 국민의 인식전환이 필요하다.

In this paper, the performance characteristics of a cryogenic refrigeration system used in fields such as HMR(Home Meal Replacement) that require ultra-low temperatures of -50℃ using natural refrigerants according to the recent enforcement of the Atmosphere Environment Conservation Act were investigated. For this purpose, a 2-stage compression refrigeration system using R744(CO2) and a cascade refrigeration system using R747/R404A and R747/R717(NH3) were applied. The COP(coefficients of performance) of each refrigeration system were compared according to changes in evaporation and condensation temperature, subcooled and superheated degree. Although the coefficient of performance of the 2-stage compression refrigeration system using R744 was superior to that of the cascade refrigeration system, 2-stage refrigeration system was considered that various problems should be solved in practical terms. In addition, the COP of R744/R717 for various operating conditions showed similar results to R744/R404A, so the possibility of alternativeness could be confirmed in the cascade refrigeration system.

With the advent of the 4.0 era of logistics due to the Fourth Industrial Revolution, infrastructures have been built to receive the same services online and offline. Logistics services affected by logistics 4.0 and IT technology are rapidly changing. Logistics services are developing using technologies such as big data, artificial intelligence, blockchain, Internet of things, and augmented reality. The convergence of logistics services and various IT new technologies is accelerating, and the development of data management solution technology has led to the emergence of electronic cargo waybill to replace paper cargo waybill. The electronic waybill was developed to supplement paper waybill that lack economical and safety. However, the electronic waybill that appeared to complement the paper waybill are also in need of complementation in terms of efficiency and reliability. New research is needed to ensure that electronic cargo waybill gain the trust of users and are actively utilized. To solve this problem, electronic cargo waybill that combine blockchain technology are being developed. This study aims to improve the reliability, operational efficiency and safety of blockchain electronic cargo waybill. The purpose of this study is to analyze the blockchain-based electronic cargo waybill system and to derive evaluation indicators for system supplementation.