• Journal of the Korean Professional Engineers Association
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• v.23 no.1
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• pp.49-63
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• 1990

A signalling system generally designates electrical conditions and transmissionㆍreceiving programs of exchange control use signals concerning the establishmentㆍreleaseㆍtariff etc of calls between telephone subscribers and an exchange office or inter-exchange offices. In signalling system, different systems are being used according as communication service for control. With the development of exchange and transmission technique and higher functional advance, there exist many kinds of signalling systems. As for the signalling system used in international communication, an international standardization is specially important for the exchange of each country to operate properly and execute a smooth exchange connection. A term "signalling system" is chiefly used in telephone exchange system, while in telex exchange system "signalling condition, " and in data exchange system "protocol" is used. "protocol" is used.; is used.

• Journal of the Korean Dietetic Association
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• v.9 no.2
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• pp.159-171
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• 2003

The food composition tables are frequently used to health and nutrition practices. But it is difficult to find out food exchange lists with food exchange groups in the food composition table. Over 2500 items and many kinds of nutrients are in the food composition table. But now food exchange lists are used a few foods. The internet demands the users needs for obtaining more food exchange lists and nutrient information from food composition. This basic study is to solve the users need and the supply more efficient and effective manipulation system for e-food exchange database construction and search system:ENECC/e-food exchnage(E-Nutrition Education and Couseling Center/e-food exchange). This paper introduces the food exchange database construction and search system(ENECC/e-food exchange) using the formula which calculates the food exchange quantity of 6 food exchange groups and added one extra groups(alcohol) based on the internet. The ENECC/e-food exchange database is basically based on the 6th food composition table(2001) of the National Rural Living Science Institution in Rural Development Administration, Korea. The e-food exchange database are consisted of 2,261 foods in 6 basic food groups and one extra groups by using ENECC calculating formula. Also, the e-food exchange database has the proximate composition, mineral and vitamin content such as energy, moisture, protein, fat, carbohydrate, ash, calcium, phosphorus, iron, sodium, potassium, retinol equivalent, retinol, â-carotene, thiamin, riboflavin, niacin, ascorbic acid, refuse per 100g of each food.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.2052-2058
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• 2009

The standardized and open information model called common language and information exchange format should be firstly defined for the interoperable power system and two-way information exchange among the components of the power system. The information models and information exchange formats for power facilities and power system applications are being defined in power system area, but the information model and information exchange format for the consumer area are not being yet defined besides of metering information model. An architecture and open standard for the information exchange between energy service provider and consumer are required to provide various value added services through the networking with devices in consumer premise. In this paper, an architecture for the two-way communications between energy service provider and consumer is defined and psXML(power system XML) for the information exchange is designed.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.100-102
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• 2007

본 논문에서는 혼합정수 선형계획 법을 이용하여 장기 전력계통 계획수립시 최적의 설비를 투자할 수 있는 기법을 제안하였다. 발전설비와 송변전설비는 하나의 망으로 연결되어 상호 보완적 영향을 주기 때문에 계통계획시 두 설비를 동시에 평가하는 것이 무엇보다 중요하다. 또한 계획기간 전체에 대해 투자비를 고려하여 비용을 최소화해야 한다. 이를 위해 선형계획법을 계통계획에 도입하여 최소비용의 투자비를 가지고 공급 신뢰도 기준를 만족할 수 있는 최적 장기 전력계통 계획 수립기법을 개발하였다. 개발된 기법을 Garver 6모선 계통 및 제3차 전력수급기본계획에 대해 모의하여 결과의 타당성을 검증하였다.

• Nuclear Engineering and Technology
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• v.29 no.3
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• pp.251-259
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• 1997

This paper describes experimental investigations of helium-air exchange flows through partitioned opening and too-opening. Such exchange flows may occur following rupture accident of stand pipe in high temperature engineering test reactor. A test vessel with the too types of small opening on top of test cylinder is used for experiments. An estimation method of mass increment is developed to measure the exchange now rate. Upward flow of the helium and downward flow of the air in partitioned opening system interact out of entrance and exit of the opening. Therefore, an experiment with too-opening system is made to investigate effect of the fluids interaction of partitioned opening system. As a result of comparison of the exchange flow rates between too types of the opening system, it is demonstrated that the exchange flow rate of the two-opening system is larger than that of the partitioned opening system because of absence of the effect of fluids interaction.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.477-484
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• 2014

In this paper, we propose a new optical secret key sharing method based on the Diffie-Hellman key exchange protocol required in cipher system. The proposed method is optically implemented by using a free-space interconnected optical logic gate technique in order to process XOR logic operations in parallel. Also, we present a compact type of optical module which can perform the modified Diffie-Hellman key exchange for a cryptographic system. Schematically, the proposed optical configuration has an advantage of producing an open public key and a shared secret key simultaneously. Another advantage is that our proposed key exchange system uses a similarity to double key encryption techniques to enhance security strength. This can provide a higher security cryptosystem than the conventional Diffie-Hellman key exchange protocol due to the complexity of the shared secret key. Results of numerical simulation are presented to verify the proposed method and show the effectiveness in the modified Diffie-Hellman key exchange system.

• Safety and Health at Work
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• v.5 no.2
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• pp.53-59
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• 2014

Background: In a safety perspective, efficient knowledge management is important for learning purposes and thus to prevent errors from occurring repeatedly. The relationship between knowledge exchange among employees and safety behavior may be of particular importance in distributed organizational systems where similar high-risk activities take place at several locations. This study develops and tests hypotheses concerning the relationship between knowledge exchange systems usage, knowledge exchange in the organizational system, and safety compliance. Methods: The operational context of the study is petroleum drilling and well operations involving distributed high-risk activities. The hypotheses are tested by use of survey data collected from a large petroleum operator company and eight of its main contractors. Results: The results show that safety compliance is influenced by use of knowledge exchange systems and degree of knowledge exchange in the organizational system, both within and between units. System usage is the most important predictor, and safety compliance seems to be more strongly related to knowledge exchange within units than knowledge exchange between units. Conclusion: Overall, the study shows that knowledge management is central for safety behavior.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.750-757
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• 2009

The ammonium ion exchange characteristics of natural zeolite were investigated to remove ${NH_4}^+-N$. The effect of water temperature, particle size and competitive cation on the exchange capacity was examined. Ammonium ion exchange capacity tended to decrease when the temperature increased from $25^{\circ}C$ to $40^{\circ}C$. Exchange capacity was increased according to the particle size of natural zeolite comes to be small. Batch isotherm experiments were conducted for measuring ammonium ion exchange capacity. The ion exchange capacity was well described either by the Langmuir isotherm model or by the Freundlich isotherm model. The ammonium ion exchange capacity ($q_m$) of zeolite carrier can be calculated $11.744mg-{NH_4}^+/g$-carrier. The ion exchange capacity of manufactured zeolite carrier was showed a similar tendency as ion exchange capacity of powder-sized natural zeolite. Therefore, zeolite carrier can be used for increasing of nitrogen removal efficiency in the wastewater treatment plants.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.4
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• pp.372-380
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• 1997

This paper describes experimental investigations of helium-air exchange flows through parti¬tioned opening and two-opening. Such exchange flows may occur following rupture accident of stand pipe in high temperature gas cooled reactor. A test vessel with the two types of small open¬ing on top of test cylinder is used for experiments. An estimation method of mass increment is developed and applied to measure the exchange flow rate. A technique of flow visualization by Mach-Zehnder interferometer is provided to recognize the exchange flows. In the case of exchange flow through the partitioned opening, flow passages of upward flow of the helium and downward flow of the air within the opening are separated by vertical partition, and the two flows interact out of entrance and exit of the opening. Therefore, an experiment of the exchange flow through two-opening is made to investigate effect of the fluids interaction of the partitioned opening sys¬tem. As a result of comparison of the exchange flow rates between the two types of the opening system, it is found that the exchange flow rate of the two-opening system is larger than that of the partitioned opening system due to absence of the effect of fluids interaction. Finally, the fluids interaction between the upward and downward flows through the partitioned opening is found to be an important factor on the helium-air exchange flow.

• Journal of the Korean Dietetic Association
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• v.10 no.2
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• pp.129-142
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• 2004

The food exchanges are frequently used to nutrition education and counseling for diabetes, weight control, hyperlipidema and etc. But it is difficult to find out food exchange lists with food exchange groups in the food composition table. This study was conducted to select e-food exchange of commonly used foods(456 foods) and improve search system based on internet. Also, the e-food exchange database was developed as having the proximate composition, mineral and vitamin content such as energy, moisture, protein, fat, carbohydrate, ash, calcium, phosphorus, iron, sodium, potassium, retinol equivalent, retinol, a-carotene, thiamin, riboflavin, niacin, ascorbic acid, refuse per 100g of each food. The e-food exchange database developed is basically based on the 6th food composition table(2001) of the National Rural Living Science Institution in Rural Development Administration, Korea. The 456 commonly used foods or 2,262, all foods can be searched easily in a new system. A specific food of e-food exchange can be searched by a given set of food groups or food name and can give information about food one exchange lists, weight and nutrient value per 100g of each food user-friendly on internet. It can be used to make a nutritionally balanced meal plan, nutrition education and counseling.