• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.183-192
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• 2009

A turn-buckle inserted between tension members sustaining structural loads in the suspension structure system is a device capable of adjusting the tensile force. However, it is difficult to measure the tensile force that is applied to the tension member with the use of a conventional turn-buckle. So a measurable turn-buckle for tensile force measurement has been developed to improve on such a problem. This study focuses on the prevention of a local yielding as well as the maximization of yielding load mentioned in previous studies. A new type of turn-buckle for the measurement to practical use is suggested over the tentative purpose. For this purpose, the ABAQUS analysis of specimens based on theoretical analysis and tests are carried out. The differences among the results of the theoretical analysis, ABAQUS analysis, and the test were insignificant.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.185-191
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• 2016

The Hybrid Safety Injection Tank is a passive safety injection system that enables the safety injection water to be injected into the reactor pressure vessel throughout all operating pressures by connecting the top of the SIT and the pressurizer(PZR). In this study, the condition for balancing the pressure between the Hybrid SIT and PZR was derived theoretically. The pressure balancing condition was set at the point where the velocity of the Hybrid SIT coolant injected into the Direct Vessel Injection(DVI) line was at or above zero. If the condition was derived from a pressure network for the Hybrid SIT, pressurizer, and reactor pressure vessel, the pressure difference between the pressurizer and SIT is less than 0.07 MPa.

• Journal of Chest Surgery
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• v.34 no.2
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• pp.148-155
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• 2001

배경: 본 연구는 1987년부터 1997년까지 원자력병원에서 수술을 시행한 500명의 식도암환자를 대상으로 하여 휴향적 방법을 통해 조기 및 장기성적, 재발양상, 예후인자 등을 보고하고자 한다. 대상 및 방법: 대상환자 중에서 발병암이 있는 경우, 인두식도 경계부위나 위식도 경계부위 암, 고식적 우회술 또는 인공식도 삽입예 그리고 시험적 개흉술이나 개복술 만을 시행한 경우는 제외 시켰다. 식도 절제는 대부분 우측 개흉술을 이용한 Ivor Lewis 술식을 사용하였고 대부분의 문합은 stapler를 사용하였다. Extended lymph node dissection은 1994년 8월부터 시행하였고 그 이전에는 standard lymph node dissection을 하였다. 96.8%에서 위를 식도 대체장기로 사용하였고 경부에서 절제 및 재건술을 시행한 경우를 제외한 모든 식도재건은 후종격동을 통해 시행하였다. 결과: 474예(94.8%)가 편평상피 세포암이었고 대부분(58.2%)은 중부식도에 위치하였다. 술후병기는 47.4%가 stage III이었고 25%가 stage IIA이었다. 392예에서 근치적 절제가 가능하였고 74예는 고식적 절제를 시행하였으며, 식도열공을 통한 식도절제술과 경부에서의 유리공장 이식술을 시행한 34예는 위분류에서 제외하였다. 술후 유병율은 38.4%이었고 수술 사망률은 5.8%로 호흡기 감염, 문합부 유출이 주요 원인이었다. 대상환자의 99.8%에서 추적은 가능하였고 수술사망 예를 포함한 전체환자의 1, 2, 5년 생존율은 각각 63.5%, 38.9%, 19.4% 이었다. Standard lymph node dissection 그룹에서의 1, 2, 5년 생존율이 60.7%, 35.9%, 16.9%이었으나 extended lymph node dissection그룹에서는 1, 2, 4년 생존율이 70.2%, 46.5%, 30.9%이었다. 근치적 절제의 경우는 1, 2, 5년 생존률이 69.4%, 43.9%, 21.9%이었고, 고식적 절제의 경우는 37.8%, 17.6%, 7.3%이었다. 수술사망을 제외한 근치적 절제술과 extended lymph node dissection을 함께 시행한 경우의 4년 생존율은 35.6%이었다. 수술후 재발은 226예에서 발견되었고 주로 국소임파절(69%; 경부, 종격동, 복부)이었으며, 전신재발은 간, 폐, 뼈, 뇌 등의 순이었다. 결론: 저자들은 적절한 술후 환자관리가 선행되어야 하지만 근치적 절제와 광범위한 임파절 절제가 장기성적의 향상에 필수적 요소이고, 진행된 식도암에 있어서는 보다 효과적인 보강적 복합치료가 연구되어야 할 것으로 생각된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.81-85
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• 2006

Through-the-thickness properties of thick-walled cylindrical composites are required to determine structural performances because interlaminar tensile stress is primarily responsible for structural failure of the composites during their curing process. It is necessary for evaluating the tensile properties to find individual test methods to find appropriate methods because there are no recognised international standards(test methods and test specifications) available for generating reliable tensile properties in the direction. This paper has performed an experimental Study to measure that properties of carbon fabric/phenolic composites are produced by domestic company. Several test methods using an aluminum specimen were compared and evaluated. The best method, found out, was adopted to measure transverse through-the-thickness properties of composite materials. The results show that strain trends on four faces of composite specimen are the same.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.76-80
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• 2017

With the fast growing popularity of small UAVs (Unmanned Aerial Vehicles), recent UAV systems have been designed and utilized for the various field with their own specific purposes. UAVs are opening up many new opportunities in the fields of electronics, sensors, camera, and software for pilots. Increase in awareness and mission capabilities of UAVs are driving innovations and new applications driven with the help of low cost and its capability in undertaking high threat task. In particular, small unmanned aerial vehicles should fly in environments with high probability of unexpected sudden change or obstacle appearance in low altitude situations. In this paper, current researches regarding techniques of autonomous flight of smal UAV systems are introduced and we propose a draft idea for planning paths for small unmanned aerial vehicles in adversarial environments to arrive at the given target safely with low cost sensors.

• Journal of Digital Convergence
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• v.15 no.8
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• pp.477-487
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• 2017

This paper releases strategies for firms that wish to enter into online circulation business in China. SWOT based on a Korean manufacturing company teaches us better way to approach Chinese online market. Chinese online market is under oligopoly, where Alibaba and Jingdong account for about 80% of the total market. Game theory is used as a measure of threat and opportunity between Korean manufacturer and Chinese online market retailer. Game shows that they are easy to accept opportunity and sales uplift rather than low risk. Analysis shows that Korean companies should improve its products and brand competitiveness in the offline market before entering into the Chinese online retail market. They need to prepare a localization model.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.185-194
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• 2007

Today, there is in the world-wide cognition about RFID technology due to established standard, EPC(Electronic Product Code). RFID technology will have wide influence over various fields. Especially, RFID technology's advantages will have positive influence on logistics field. We can solve limited various problems presented in SCM by applying RFIB technology. We can have higher cantrol system, better benefits and actual decision information. Many organizations, however, still have hesitated now because RFID technology has not been validated and RFID technology is in early stage. Other problems are employee resistance against new technology and lack of academic empirical research on assimilation RFID technology for organization. Above reasons I mentioned make me study on analysis on assimilation RFID technology decision in SCM field. This study attempts to analyze the assimilation RFID technology factor from previous researches by using AHP. This outcomes of study will be helpful when we assimilate RFID technology in SCM fields.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.4
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• pp.61-76
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• 2012

The research reports the results from an investigation of various measurement elements and techniques appropriate for the economic assessment of academic libraries, with a view to apply them in future evaluation of academic libraries in Korea. Two libraries participated in the pilot study. In one library, CVM (contingency valuation method) was applied to services ranging from circulation, electronic collection, reference, user education and facility. In the second library, three different methodologies--time value, alternative service value and CVM--were all applied to measure the value of electronic collection. The research provides analyses of measurement elements used, study procedures and measurement results. Based on these analyses, the study also makes suggestions in the areas of measurement goals, service, users and the calculation of B/C ratios that need to be taken into consideration in order to execute reliable and valid assessment of academic library's value.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.3
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• pp.7-13
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• 1993

Fracture behavior of pre-cracked compact tension specimens made of AISI 4130 steel was investigated using acoustic emission (AE) and ultrasonic C-scan measurements. While each specimen was loaded up to a certain level, various acoustic emission parameters were recorded together with the crack opening displacement (COD). An elastic-plastic finite element analysis was performed to calculate COD and the damage (plastic) zone size ahead of crack tip. Ultrasonic C-scans, in a pulse-echo, immersion mode, were done for mapping the damage zone size. The agreement between the finite element results and the measured COD was satisfactory. Based on AE results, the test specimens were found to show ductile behavior. The slope of the total ringdown counts vs. COD curve was useful to determine the crack initiation. The preliminary C-scan images showed evidence of changes in the amplitude of ultrasonic signal in the damaged region, and the shape and size of the damage zone matched qualitatively with the finite element results. A further work on the damage zone sizing was also pointed out.

• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.13-26
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• 2009

Wireless Sensor Networks (WSNs) is one of the key technologies that make it possible to provide u-service in a ubiquitous society, however, it has disadvantages such as difficulty of managing sensor nodes and weaknesses of stability or mobility in large-scale WSNs. In order to solve these problems, 6LoWPAN that integrates with WSNs and IP networks has been studied widely. In this paper, we propose a Location Tracking Service Based on Google Map (LTSGM) system using 6LoWPAN. Since LTSGM system provides visual location information of sensor nodes through Google Map, it is possible to makes it easier than ever to manage sensor nodes in large-scale WSNs. Moreover, LTSGM can be used for various services such as applications for disaster or crime because it can trace the location of mobile nodes. Implementation of LTSGM system will be a test platform for 6LoWPAN.