• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.40 no.5
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• pp.18-24
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• 2011

태양열 집열기에서 생산된 열원을 축열한 축열조의 온수를 겨울에는 직,간접 열교환을 통하여 난방을 실현하고 축열조의 여름에는 흡수식 냉동기 발생기(Generator)에 공급하여 흡수식 냉동기를 가동하고 냉동기에서 생산된 저온의 냉수로 냉방을 실현하는 태양열 냉난방 겸용시스템에 대한 설치 사례를 소개하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.32-38
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• 2009

In this paper, cycle performance analysis for cooling capacity, compression work and COP of R744($CO_2$) transcritical vapor compression refrigeration system is presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include superheating degree, outlet temperature of gas cooler and evaporating temperature in the R744 vapor compression cycle. The main results were summarized as follows : The cooling capacity of R744 increases with superheating degree, but decreases with the increasing evaporating temperature and outlet temperature of gas cooler. The compression work increases with superheating degree and cooling pressure of R744, but decreases with the increasing evaporating temperature. And, The COP increases with outlet temperature and evaporating temperature of R744 gas cooler, but decreases with the increasing superheating degree. Therefore, superheating degree, outlet temperature and evaporating temperature of R744 vapor compression refrigeration system have an effect on the cooling capacity, compression work and COP of this system. With a thorough grasp of these effect, it is necessary to design the compression refrigeration cycle using R744.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1427-1433
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• 2012

In this paper, cycle performance analysis of cascade refrigeration system using alternative FREON refrigerants and natural refrigerants are presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include subcooled and superheated degree, and condensing and evaporating temperature, temperature difference of cascade heat exchanger in cascade refrigeration system. The COP of cascade refrigeration system increases with the increasing subcooled degree, but there is no significant changes with the increasing superheated degree. The COP of cascade refrigeration system depends on evaporating and condensing temperatures of cascade heat exchanger. Therefore, subcooled degree, evaporating and condensing temperature of cascade heat exchanger using alternative FREON refrigerants and natural refrigerants have an effect on the COP of this system. In this paper, COP of cascade refrigeration system using (R23 / R290), (R23 / R600), (R23 / R600a), (R23 / R717), (R744 / R404A) are higher 20 ~ 36 % than (R23 / R22), using R23 for low temperature system and R22 for high temperature system.

• Journal of the KSME
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• v.53 no.4
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• pp.44-48
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• 2013

이 글에서는 초전도가속기의 개념과 그 운전을 위해 필수적인 설비인 극저온 헬륨 냉동시스템에 대해 소개하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.738-741
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• 2011

창고관리 시스템은 RFID(Radio Frequency Identification) 기술을 이용하여 입 출고 관리에 대한 데이터를 자동으로 기록할 수 있을 뿐만 아니라 상품의 적재 위치를 정확히 보여주고, 적재된 상품의 현재 상태, 배치된 상품의 수량, 재고 상황 등의 정보를 실시간으로 확인 할 수 있게 해준다. 특히 냉동창고의 경우, 물품이 외부환경 요소에 민감하기 때문에 물품보관을 요청한 화주의 입장에서는 물품의 상태를 실시간으로 모니터링 하기를 원한다. 본 논문에서는 RFID 냉동창고를 이용하는 화주에게 본인의 물품상태를 실시간 원격으로 모니터링할 수 있도록 해 주는 스마트폰 기반의 애플리케이션의 개발내용에 대해 기술한다. 본 애플리케이션을 통해 화주는 물품의 입고요청, 출고요청을 실시간으로 보낼 수 있을 뿐만 아니라, 적재되어 있는 물품의 현재위치, 적재위치 이동경로, coldroom의 온도 등의 상태정보도 확인 할 수 있다. 냉동창고 업체는 RFID 냉동창고 관리시스템과 더불어 화주가 편리하게 이용할 수 있는 본 애플리케이션을 갖춤으로써 화주에 대한 서비스 향상에 기여하게 된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2093-2099
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• 2015

To prevent damage to the cargo, monitoring and remote management for reefer containers is necessary. The currently used remote monitoring service is the Power Cable Transmission(PCT) system, which is recommended by the International Maritime Organization(IMO). However, this system is not widely used because it requires a separate PCT infrastructure and is susceptible to data loss problems. To solve this problem, this study introduces the "IoT-based reefer container management system", The proposed system which is attached to reefer container collects and transmits data on the temperature, status and location of reefer container to middleware using RS-232 communication and WCDMA/GSM communication. Middleware is store the data received in the database and provide information to user in real time through the web and mobile program. At this time, users able to change setting temperature in real time from a distant place through the web program. This study tested by transit about shipment of strawberries to monitor and analyze and check the system's overall effectiveness.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.267-272
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• 2004

In this paper a new intelligent diagnostic system for a refrigerator used for a cold-storage of farm produce was propose. It is verified that the developed system is useful for the fault observation and diagnose of a refrigerator by experimental implementation. The basic idea of the proposed system in that the temperature of major pipes at fault status differs from those at normal status. In order to realize the proposed system, the temperature measuring system and diagnostic program were developed.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.1
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• pp.23-39
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• 2005

As developing satellite communication, the tracking range of the moving objects which move in local area is expanded to the whole world. However previous logistics management system is able to monitor freight which transporting in local area using mobile communication system. In this paper, we propose the reefer container management system that manages the location information and other related information such as temperature, humidity of container using the satellite system. The proposed system consists of three parts; data collector, satellite communication manager, reefer container information manager. And the proposed system uses the moving object index for managing the trajectory of container and tracing the location of container or vessel that is transporting the container, and supports various services such as reefer container and vessel tracking, container control and container statistics to logistic companies like shipper and forwarding agent. And the system can be increasing the quality of container transportation service to the shipper, and it makes the efficient management of reefer container to the shipping company.

• Journal of the Korea Society of Computer and Information
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• v.19 no.6
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• pp.109-117
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• 2014

A cold storage is a warehouse of a insulated building with cooling installations. It has many different types of cold rooms with temperatures below 0 degrees Celsius, and the sequential workflow such as receiving, picking and packing runs in that rooms. Recently, the cold storages have adopted RFID technology, and consequently, warehouse product management in them are becoming intelligent and network. However, information inconsistency in warehouses caused by physical and logical errors reduces reliability in the RFID cold storage management system and worsens their work efficiency. Therefore, it is necessary to develop an early detection system to identify errors. In this paper, we suggest a supervisory system detecting logical errors on business processes of the RFID cold storage. It is composed of a master supervisor and mobile supervisor. In the master supervisor, the manager can set the constraints conditions and get alerts, and in the mobile supervisor, the workers confirm and deal with these faults directly. The supervisory system improve reliability of the RFID cold storage management system by recognizing a failure to identify physically and logically using these constraint conditions. This paper shows that the supervisory system can reduce the average recovery time to improve reliability by decreasing the time for detecting and analyzing errors in the RFID cold storage management system.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.77-82
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• 2020

In this paper, we developed a cooling system for the refrigeration truck using natural carbon dioxide refrigerant which is attracting attention as an environmentally-friendly refrigerant. We developed a high efficient environmentally-friendly refrigerated truck that converted the existing diesel vehicle into an LNG vehicle to improve emissions of truck and improved the efficiency of the cooling system by utilizing a heat of LNG vaporization. The COP of refrigerated truck system was increased 144%.