• Tunnel and Underground Space
• /
• v.17 no.1 s.66
• /
• pp.56-65
• /
• 2007

A new underground LNG storage concept in the rock mass has been developed by combining underground cavern construction and new ice-ring harrier technologies with the conventional cryogenic insulation system. Technical feasibility of the storage system has been verified through construction and operation of the pilot storage cavern and a full-scale project is expected to start in the near future. One of the most important issues in the LNG storage system is the operational efficiency of the storage to minimize heat loss during a long period of operation due to the cryogenic heat transfer. This paper presents several important results of heat transfer and coupled hydro-thermal analyses by a finite element code Temp/W and Seep/W. A series of heat transfer analyses for full-scale caverns were performed to determine design parameters such as boil-off gas ratio (BOR), insulation thickness and pillar width. The result of the coupled hydro-mechanical analysis showed that BOR for underground storage system remains at about 0.04 %/day during the early stage of the operation. This value could be even much lower when the discontinuities in the rock masses are taken into consideration.

• KIEE International Transactions on Power Engineering
• /
• v.5A no.3
• /
• pp.244-251
• /
• 2005

Power transfer capability has been recently highlighted as a key issue in many utilities. It is determined by the thermal stability, dynamic stability and voltage stability limits of generation and transmission systems. In particular, voltage stability affects power transfer capability to a great extent in many power systems. This paper presents a tool for determining total transfer capability from a static voltage stability viewpoint using IPLAN, which is a high level language used with the PSS/E program. The tool was developed so as to analyze static voltage stability and to determine the total transfer capability between different areas from a static voltage stability viewpoint by tracing stationary behaviors of power systems. A unified power flow controller (UPFC) is applied for enhancing total transfer capability between different areas from the viewpoint of static voltage stability. Evaluation of the total transfer capability of a practical KEPCO power system is performed from the point of view of static voltage stability, and the effect of enhancing the total transfer capability by UPFC is analyzed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2002.11a
• /
• pp.63-70
• /
• 2002

The main subject to become a hub pen is automation The automated container terminal has already operated in advanced pons and it bas been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the moat optimal method of equipment operation in order to minimize loading time using each three types of effective AT operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real tine. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and the number of AGVs).

• Journal of Korea Technology Innovation Society
• /
• v.16 no.4
• /
• pp.1055-1089
• /
• 2013

These days, the environment surrounding university has been changing rapidly and largely. Especially, the academic entrepreneurship for university spin-offs and wealth creation is being emphasized. And therefore, the importance of industry-academy-research institute cooperation for technology transfer and commercialization is increasing more and more. According to that, government have made various legal system and support the university activities for their autonomous and practical technology use, and one of that core means is to make university establish the special organization for technology transfer and commercialization, and support its activities systematically. This paper aims to study legal system on the special organization for university technology transfer and commercialization in korea. Especially, it is layed emphasis to search the problems and find out the improvement ways about the special organization. For this purpose, the legal system and necessity of special organization in university and other research institute are reviewed in domestic and abroad, the type and operation methodology of special organization in the existing laws are investigated in korea, the operation effects of several organization are analyzed, and lastly the improvement methods for activating the organization are studied and suggested.

• Journal of Korea Multimedia Society
• /
• v.16 no.12
• /
• pp.1413-1426
• /
• 2013

RFID thecnology has been widely adopted by industries for supply chain management. When a product item is manufactured RFID tag is attached to the product item and supply chain management among factories, distributors, retailers and customers needs to handle ownership transfer for the product item carefully. With RFID technology, the secure and efficient ownership transfer protocol is an important issue for the identification of product items and the overall system efficiency on supply chain. Many ownership transfer protocols have been proposed now. They have security problems and use complex operations such as encryption operation and hash function. Lo et al. proposed a protocol using lightweight operations such as shift, addition, XOR, and random number generation[1]. However, this protocol has a security problem in which the secret key between the tag and the new owner is disclosed to the attackers, and it is also weak against the Fraud attack[2]. In this paper, we propose a new ownership transfer protocol using lightweight operations such as shift, addition, and random number generation. This protocol is the modified version of Lo et al.'s protocol and is secure against the security attacks.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.10 no.1
• /
• pp.29-41
• /
• 2008

This research was conducted to develop a technology transfer and farmer's extension of newly released technology of Bokto seeding method for crop and vegetable production based on the theory of Asian and Pacific Center for Transfer of Technology(APCTT). This technology has recently transferred to not only Korea but also other countries like North Korea, China, Japan, Taiwan, Russia and Africa(Cameroon, Sudan and South Africa) since 2005. It has known as a highly reduction of production cost in terms of labors, chemical fertilizer and pesticides as well as environmental friendly due to a deep and side banded placement of chemical fertilizer at basal application. In addition this technology was proven to a precision farming on sowing depth and mechanism of chemical application method and also highly resistant against disasters like typhoon, flooding, low temperature, drought and lodging due to silicate application. It has improved a constraints such as a poor seedling establishment, weed occurrence, lodging, low yield and poor grain and eating quality in the previous direct seeding methods but still have a problem in occurrence of weedy rice and ununiformed operation of wet or flooded soil condition. Also this technology has a limit in marketing and A/S system. Based on a theory of APCTT evaluation and analysis this technology may be more concentrated on establishment of a special cooperation team among researcher and scientists, extension workers, industry sections and governmental sectors in order to rapidly transfer this technology to farmer's field. Also there will be needed to operate a web site for this newly released technology to inform and exchange an idea, experiences and newly improved information. A feed back system might be operated in this technology as well to improve a technology under way on users' operation. Also user's manual will be internationally released and provided for farmer's instruction and training at field site.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.3
• /
• pp.46-58
• /
• 2018

DRT should have higher positive benefits to become the public transit than the current backcountry buses having demand deficiency and operation problems. The study examines the factors for activating DRT through importance and performance analysis(IPA) and applies the IPA gap theory to find relationship between the current buses and DRT in the mixed operation area. As a result, the operation area is the urgent improving factor and the next ones are transfer related factors, on-time arrival, safe driving, operation time and vehicles. According to the gap theory to activate DRT and reduce the current bus system, in the case that performance is smaller than importance, the performance of transfer, operating time and area, and vehicles should be up. In the case that performance is higher than importance, the performance of luggage space, vehicle clean, safe driving, operator kindness, transfer, operating elements, and fare should keep going.

• Journal of Digital Convergence
• /
• v.11 no.1
• /
• pp.211-223
• /
• 2013

In Korea, the location of yard tractors is figured out in real time by using RFID system in container terminals. However, even though the location recognition of RFID system works fine when transfer crane is in yard operation, there are some problems when container crane is in ship operation. That is because yard tractors come one by one to each transfer crane in an order, but yard tractors come in 4 lanes to the container crane, which makes the system impossible to recognize each yard tractor separately. Therefore, we developed the infrared-ray communication system which can recognize yard tractors accurately in not only in the yard operation of transfer crane but also in the ship operation of container crane in same way in this study. The result in this study showed constant number of recognition, and the range of recognition measures 5.7m in 25m distance. The range of recognition shown in this study is enough to recognize each yard tractor passing under container crane separately.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.26 no.6
• /
• pp.437-445
• /
• 2021

This paper proposes an operating frequency design method that limits the voltage applied to aload-side converter during the initial operation of a loosely coupled resonant dual-active bridge (LCR-DAB) converter and an initial operating strategy that applies it. The LCR-DAB converter uses two wireless power transfer coils instead of the high-frequency transformer of the general DAB converter. The wireless power coil has a physical distance of several tens of millimeter or more between the two coils; thus, the LCR-DAB converter is a bidirectional isolated power conversion system that can easily achieve high insulation performance. However, for the initial operation of the LCR-DAB, if the power-side converter is operated at the resonance frequency while the load-side converter is not operating, then a very high voltage due to resonance is applied to the load-side converter, thereby causing damage to the converter. Therefore, a method that can stably charge the DC link voltage of the secondary-side converter during the initial operation is needed. This paper proposes a method to initially charge the secondary-side DC link by operating the primary-side converter at a frequency with limited voltage gain rather than at a steady-state operating frequency. The validity of the proposed frequency design method and initial operating sequence is verified through simulation and experimentation of the 1 KW LCR-DAB converter.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.761-772
• /
• 2009

The introduction of KTX (Korea Train eXpress) provided passengers with a much faster mode of transport, and KTX has become a model railway system. Express railway stations are emphasized as public transit transfer centers, but their service evaluations were not performed appropriately so far. It is possible to know the level of service by developing valuation criteria for their evaluations. The evaluation of transfer centers mainly consists of two parts; connective service with other travel m odes, and transfer service inside transfer stations. Connection is defined as the inter-connection of multi-transportation vehicles, and transfer means that a passenger changes his travel mode to another. Such connective service and transfer service are evaluated by the level of service in terms of transfer facilities, the appropriateness of station layout and the quality of information throughout the facilities. We developed the service evaluation indicators of connective facilities and referred to the indicators of transfer facilities. We examined the 7 stations in Korea that are currently in operation and standardized the methodology of the evaluation process by applying the indicators suggested in this study.