• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.452-452
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• 2014

블랑켓 일차벽이나 디버터와 같은 핵융합로 플라즈마 대향부품은 플라즈마로부터 입사되는 중성자 및 입자들을 차폐하여 구조물을 보호하고, 발생열을 에너지로 변환하기 위해 냉각재를 활용한 열제거 기능을 담당한다. 특히, 고속중성자와 입사 열부하 및 여러 입자들로부터 블랑켓 및 내부 구조물을 보호하기 위해 차폐체와 구조물로 구성된다. 세계적으로 차폐체로서는 텅스텐 혹은 텅스텐 합금, 구조물용 재료로는 저방사화 Ferritic Martensitic (FM) 강이 유력한 후보재료로 개발, 연구 중에 있다. 국내에서는 국제핵융합로(ITER) 사업을 통해 고온등방가압(HIP, Hot Isostatic Pressing)을 이용한 이종금속간 접합기술과 한국형 저방사화 고온구조재료인 ARAA (Advanced Reduced Activation Alloy)가 개발되고 있으며, 이를 활용한 설계, 접합법 개발, 제작목업의 건전성 평가 등이 수행되고 있다. 한국원자력연구원에서는 핵융합 기초사업의 일환으로 전북대와 공동으로 수행 중인 건전성 평가체계 개발을 위해, 기 개발된 접합법을 활용한 $45mm(H){\times}45mm(W){\times}2mm(T)$의 W/FM강 목업을 제작한 바 있으며, 이를 국내 구축된 고열부하 시험 장비인 KoHLT-EB (Electron Beam)를 활용한 고열부하 인가 건전성 평가시험을 준비 중에 있다. 이종금속간 접합 특성은 기계적 평가를 위한 파괴시험을 통해 검증, 이를 활용한 목업이 제작되었으며, 제작된 목업에 대한 초음파를 이용한 접합면의 비파괴 검사를 통해 결함이 없음을 확인하였다. 최종적으로 실제 사용되는 핵융합 운전조건과 유사 혹은 가혹한 조건에서 고열부하를 인가하여, 그 건전성을 평가가 이루어질 것이다. 고열부하 시험을 위해서는 냉각조건, 인가 열부하, 수명평가를 통한 반복 고열부하 인가 횟수 등이 사전에 결정되어야 한다. 이를 위해 상업용 열수력, 구조해석 코드인 ANSYS-CFX와 -mechanical을 이용한 시험조건 모의 및 수명 평가가 수행되었다. 구축 장비의 냉각계통을 고려하여 냉각수의 온도 및 속도는 $25^{\circ}C$, 0.15 kg/sec로, 열부하는 0.5 및 $1.0MW/m^2$에 대해 모의를 수행하였다. 정상상태 시 텅스텐의 최대 온도는 각 열부하 조건에 따라 $285.3^{\circ}C$와 $546.8^{\circ}C$였으며, 이에 도달하는 시간을 구하기 위해 천이해석을 수행하였고, 이를 통해 30초에 최대온도 95 %이상의 정상상태 온도에 도달함을 확인하였다. 또한, 목업의 초기 온도에 도달하는 냉각시간도 동일한 천이해석을 통해 30초로 가능함을 확인하였고, 최종 시험 조건을 30초 가열, 30초 냉각으로 결정하였다. 결정된 반복 열부하 인가 조건에서 이종금속 접합체가 받는 다른 열팽창 정도에 따른 응력을 계산하여 목업의 수명을 도출하였고, 이를 시험해야 할 반복 횟수로 결정하였다. 각 열부하 조건에 따른 온도조건을 ANSYS-mechanical 코드를 활용하여 열팽창과 이에 따른 접합면의 응력분포로 계산하였다. 0.5 및 $1.0MW/m^2$에 대해, 목업이 받는 최대 응력은 334.3 MPa와 588.0 MPa 였으며, 이 때 텅스텐과 FM강이 받는 strain을 도출하여 물성치로 알려진 cycle to failure 값을 도출하였다. 열부하에서 예상되는 수명은 0.5 및 $1.0MW/m^2$에 대해, 100,000 사이클 이상과 2,655 사이클로 계산되었으며, 시간적 제약을 고려 최종 평가는 $1.0MW/m^2$에 대해, 3,000사이클 정도의 실험을 통해 그 수명까지 접합건전성이 유지되는 지 실험을 통해 평가할 예정이다.

• Journal of Wetlands Research
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• v.22 no.3
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• pp.194-199
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• 2020

Unlike in the past, the world is facing water shortages due to climate change and difficulties in simultaneously managing the risks of flooding. The Four Major Rivers project was carried out with the aim of realizing a powerful nation of water by managing water resources and fostering the water industry, and the construction period was relatively short compared to the unprecedented scale. Therefore, the prediction and analysis of how the river environment changes after the Four Major Rivers Project is insufficient. Currently, part of the construction section of the Four Major Rivers Project is caused by repeated erosion and sedimentation due to the effects of sandification caused by large dredging and flood-time reservoirs, and the head erosion of the tributaries occurs. In order to solve these problems, the riverbed maintenance work was installed, but it resulted in erosion of both sides of the river and the development of new approaches and techniques to keep the river bed stable, such as erosion and excessive sedimentation, is required. The water agent plays a role of securing a certain depth of water for the main stream by concentrating the flow so much in the center and preventing levee erosion by controlling the flow direction and flow velocity. In addition, Groyne products provide various ecological environments by forming a natural form of riverbeds by inducing local erosion and deposition in addition to the protection functions of the river bank and embankment. Therefore, after reviewing the method of determining the shape of the Groyne structure currently in use by utilizing the mobile limit flow rate and marginal reflux force, a new Critical Movement Velocity(${\bar{U}}_d$) and a new resistance coefficient formula considering the mathematical factors applicable to the actual domestic stream were developed and the measures applicable to Groyne installation were proposed.

• Korean Security Journal
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• no.39
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• pp.37-61
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• 2014

Nowadays the world is threatened because of terrors that take aim at Soft-Targets available and easy to access to the people rather than more secured Hard-Targets. The inspection department of the Presidential Security Service develops and acts a perfect safety plan wherever the President stays so that it is possible to get immediate actions for various contingencies. Some events, in which the President take part, could be held in a lower or higher store in a tall building. Additional to the routine work at this case it is to emphasize on a plan of fire precaution to check the spot and respond to a real fire situation, so that the damage could be minimized. First, the agents of the President Security Service should possess basic knowledge concerning to the fire accidents and be trained on their manuals, even in a busy events plan. An organization, whatever it is, could be improved in that it tries to develop not only the personal abilities, but also education programs of the organization continually. And enhanced abilities of the members lead to the driving force for the advance. The knowledge of fire accident should be able to adapt to the real situation. Second, related to the event, it should be cooperated with the relevant departments, so that it is possible to conduct and control the system. It is urgently required to know that the security event could not be done perfectly with only one part or department. Third, from the time of recognizing of the event it is necessary for the fire department to get an action plan with fire fighting measures, evacuation measures based of the instructions given by the Security Service. Fourth, on the knowledge of the action plan of the fire department the Security Service should inspect the safety activities of the spot and establish the practical operation plan through the fire fighting and evacuation plan. Fifth, the Security Service should share final informations and plan of fire fighting in a high-rise building with the other relevant departments. If not, it could cause a great confusion that could lead to a great damage.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.1
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• pp.159-165
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• 2018

In recent years, universal design concepts have been introduced that are designed to make everybody more comfortable and safe to use for products, buildings, environments, services, and so on. In the case of urban railroad history, it is important to maintain facilities that incorporate the universal design concept because it is an important facility that serves as a base of city life and there are various users. This research is the last annual task of 5 years as part of the project of "Development of Technique to Improve the Convenience of Urban Railway History User" by the National Institute of Transportation Technology Promotion Agency. The purpose of this study is to develop criteria and method of facilities convenience evaluation based on UD and to evaluate user convenience by selecting test bed station. For this purpose, the UD principle of the historic facilities of Weihai Urban Railway was established and detailed evaluation criteria were presented. As a result of evaluating the test bed history using the 5-point Likert scale of the joint research institute / railway operating agency / expert, 50.3% of convenience improvement was achieved. As a result of evaluating the applicability according to the UD principle, 48.7% Respectively. The evaluation criteria and methodology based on the UD suggested in this study is a quantitative method for evaluating UD application of urban railway facilities in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.375-382
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• 2020

As the 4th Industrial Revolution era in worldwide, interest in autonomous vehicles is increasing. but due to recent safety issues such as pedestrian accidents and car accidents, as a technical model for this, the demand for 3D HD maps (High Definition maps) is increasing in including lanes, road markings, road information, traffic lights and traffic signs etc. However, since some complementary points have been continuously raised according to demand, It is necessary to collect the opinions of institutions and companies utilizing HD maps and to improve HD maps. This study was conducted by utilizing the results of the contest for usability verification of HD Maps hosted by the National Geographic Information Institute and organized by the Spatial Information Industry Promotion Institute. For this study, we researched HD maps' layers and codes for HD maps object usability to improve HD maps, constructed HD maps object usability items accordingly, and contested usability verification of HD maps according to the items The contestants conducted verification and analyzed the results. As a result, the most frequently used code for each layer was the flat intersection, and the code showing the highest usage rate was a safety sign. In addition, the use rate of the sub-section and height obstacles was 16.67% and 8.88%, respectively, showing a low ratio. In order to utilize HD maps in the future, this study is expected to require research to continuously collect opinions from customers and improve data objects and data models that are actually needed by customers.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.3-54
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• 2013

Nowadays, major advanced countries in aviation technology are putting their effort to develop commercial and civil Unmanned Aircraft System(UAS) due to its highly promising market demand in the future. The market scale of commercial and civil UAS is expected to increase up to approximately 8.8 billon U.S. dollars by the year 2020. The usage of commercial and civil UAS covers various areas such as remote sensing, relaying communications, pollution monitoring, fire detection, aerial reconnaissance and photography, coastline monitoring, traffic monitoring and control, disaster control, search and rescue, etc. With the introduction of UAS, changes need to be made on current Air Traffic Management Systems which are focused mainly manned aircrafts to support the operation of UAS. Accordingly, the legislation for the UAS operation should be followed. Currently, ICAO's Unmanned Aircraft System Study Group(UASSG) is leading the standardization process of legislation for UAS operation internationally. However, some advanced countries such as United States, United Kingdom, Australia have adopted its own legislation. Among these countries, United States is most forth going with President Obama signing a bill to integrate UAS into U.S. national airspace by 2015. In case of Korea, legislation for the unmanned aircraft system is just in the beginning stage. There are no regulations regarding the operation of unmanned aircraft in Korea's domestic aviation law except some clauses regarding definition and permission of the unmanned aircraft flight. However, the unmanned aircrafts are currently being used in military and under development for commercial use. In addition, the Ministry of Land, Infrastructure and Transport has a ambitious plan to develop commercial and civil UAS as Korea's most competitive area in aircraft production and export. Thus, Korea is in need of the legislation for the UAS operation domestically. In this regards, I personally think that Korea's domestic legislation for UAS operation will be enacted focusing on following 12 areas : (1)use of airspace, (2)licenses of personnel, (3)certification of airworthiness, (4)definition, (5)classification, (6)equipments and documents, (7)communication, (8)rules of air, (9)training, (10)security, (11)insurance, (12)others. Im parallel with enacting domestic legislation, korea should contribute to the development of international standards for UAS operation by actively participating ICAO's UASSG.

• Information Systems Review
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• v.6 no.2
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• pp.137-159
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• 2004

The next generation information appliances are those that can be connected with other appliances through a wired or wireless network in order to make it possible for them to transmit and receive data between them and to be remotely controlled from inside or outside of the home. Many electronic companies have aggressively invested in developing new information appliances to take the initiative in upcoming home networking era. They require systematic methods for developing new information appliances and sharing the knowledge acquired from the methods. This paper stored the knowledge acquired from developing the information appliances and developed a knowledge management system that supports the companies to use the knowledge and develop their own information appliances. In order to acquire the knowledge, this paper applied two methods for User-Centered Design in stead of using the general ones for knowledge acquisition. This paper suggested new product ideas by analyzing and observing user actions and stored the knowledge in knowledge bases, which included Knowledge from Analyzing User Actions and Knowledge from Observing User Actions. Seven new product ideas, suggested from the User-Centered Design, were made into design mockups and their videos were produced to show the real situations where they would be used in home of the future, which were stored in the knowledge base of Knowledge from Producing New Emotive Life Videos. Finally, data on present development states of future homes in Europe and Japan and newspapers articles from domestic newspapers were collected and stored in the knowledge base of Knowledge from Surveying Technology Developments. This paper developed a web-based knowledge management system that supports the companies to use the acquired knowledge. Knowledge users can get the knowledge required for developing new information appliances and suggest their own product ideas by using the knowledge management system. This will make the results from this research not confined to a case study of product development but extended to playing a role of facilitating the development of the next generation information appliances.

• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.171-184
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• 2006

According to ISAAA report, the global area of genetically modified (GM) crops increased more than 50 fold during the ten-year period from 1996 to 2005 with a sustained double-digit growth rate of 10%. This biotechnology adoption is one of the highest rates of technology adoption in agriculture history and this phenomenon indicates that the industrial value of the GM crops is highly perspective. In addition, the year 2010, 60% of cereal seeds in the global market would be GM or biotechnology related seeds so that the GM crop regards as the second green revolution that could provide a huge impact to food and agriculture. Nevertheless, there has not been any GM variety ever successfully commercialized in Korea and even none of the GM crops has ever been approved for safety testing by risk assessment. This seems that Korean agriculture industry might be indeed lost in the war of future seed market. However, lots of evidence show that Korean scientists have established advanced technologies and protocols to develop GM crops for last 20 years. Actually there have been many cases of successful transformation of crops that were previously known very difficult in transforming. Therefore, Korean agbiotechnology arena firmly holds an infrastructure for developing GM crops with a superior technology. Then what were the problems? Why has even a single GM crop not been commercialized in Korea? The tardiness shown by business in adopting the GM crop is caused by many factors: academical weakness, poor research funding, short knowledge of risk assessment, public concern, no successful experience, lack of professional leaders on GM variety development, lack of systems toward industrialization and inappropriate target transgenes from the beginning. In order to catch up in the race for the new green industry, each one of us in private sectors alongside academia and national research institutes needs to focus altogether on what can be done best in terms of choosing crops, investing fund and establishing a road map for commercialization of GM crops.

• Tuberculosis and Respiratory Diseases
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• v.57 no.1
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• pp.47-54
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• 2004

Background : Recurrent pneumonia in adults is not uncommon. However, there is no domestic data about recurrent pneumonia in adults. Therefore, we investigated the associated diseases and clinical findings of recurrent pneumonia in adults. Methods : Among 5513 patients who were treated in five teaching hospitals of Hallym medical center?over a 5-year period, we retrospectively reviewed the medical records of the 58 who were compatible with diagnostic criteria of recurrent pneumonia. Results : The number of patients with recurrent pneumonia was 58 (1.05%, 58/5513) during the 5 years. Thirtyseven patients were male and 21 were female. Mean age was 66.4 (${\pm}14.9$) years. Median interval between each pneumonic episode was 18.5 months. Associated diseases were 25 cases of respiratory diseases, 13 of heart diseases, 13 of diabetes mellitus, 7 of lung malignancies, 11 of malignancies other than lung, 7 of neurologic disease, and 8 of miscellaneous diseases. Three cases had no underlying illness. Of the 8 cases with 2 or more times of recurrence, 4 were associated with respiratory diseases, 2 with aspiration pneumonia due to neurologic diseases, 1 with heart disease and 1 with no underlying illness. Recurrent pneumonic episodes affecting the same location were 30 of the total recurrent pneumonic episodes (30/67, 47.8%) and common associated diseases were respiratory diseases including lung malignancies. The etiology of recurrent pneumonia was Streptococcus pneumoniae, methicillinresistant Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, atypical organisms, etc. Conclusion : Recurrent pneumonia in adults had a low incidence rate compared with children, but most cases had associated illness. Respiratory diseases including lung cancer were the most common associated illness of recurrent pneumonia.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2052-2063
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• 1998

Various full-scale radio location systems have been developed since ground-based radio navigation systems appeared during World War II, and more recently global positioning systems (GPS) have been widely used as a representative location system. In addition, radio location systems based on cellular systems are intensively being studied as cellular services become more and more popular. However, these studies have been focused mainly on macrocellular systems of which based stations are mutually synchronized. There has been no study about systems of which based stations are asynchronous. In this paper, we proposed two radio location algorithms in microcellular CDMA systems of which base stations are asychronous. The one is to estimate the position of a personal station at the center of rectangular shaped area which approximates the realistic common area. The other, as a method based on road map, is to first find candidate positions, the centers of roads pseudo-range-distant from the base station which the personal station belongs to and then is to estimate the position by monitoring the pilot signal strengths of neighboring base stations. We compare these two algorithms with three wide-spread algorithms through computer simulations and investigate interference effect on measuring pseudo ranges. The proposed algorithms require no recursive calculations and yield smaller position error than the existing algorithms because of less affection of non-line-of-signt propagation in microcellular environments.