• Tunnel and Underground Space
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• v.13 no.5
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• pp.397-402
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• 2003

Generally it is likely that rock mass properties are expressed not by a mean value but by values with variation due to its characteristic uncertainty. This characteristic is one of the most important parts for the design of undergound structures, but yet to be fully examined. Stochastic finite element method (SFEM) is contrary to deterministic finite element method in its concept as the former has been developed in order to take the randomness of structural systems into account. Using SFEM, the response variability of structural system can be obtained and it leads probabilistic stability of structure to be analyzed. In this study, displacement response variability of circular opening with hydrostatic stress field are analyzed in terms of rock mass properties having a certain mean and a standard deviation using the SFEM. The analyzed response variability shows that the necessity of probabilistic stability analysis of underground structures using reliable mean value and standard deviation of deformation modulus.

• Nuclear Engineering and Technology
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• v.28 no.2
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• pp.137-149
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• 1996

The present study is to analyze an integral test, BETHSY test 6.9c, which represent loss of RURS accident under mid-loop operation. Both the pressurizer manway and the steam generator outlet plenum manway are opened as vent paths in order to prevent the system from pressurization by removing the steam generated in the core. The main purposes are to gain insights into the physical phenomena and identify sensitive parameters. Assessment of capability of CATHARE2 prediction can be established the effective recovery procedures using the code in an actual plant. Most of important physical phenomena in the experiment could be predicted by the CATHARE2 code. The peak pressure in the upper plenum is predicted higher than experimental value by 7 kPa since the differential pressure between the pressurizer and the surge line is overestimated. The timing of core uncovery is delayed by 500 seconds mainly due to discrepancy in the core void distribution. It is demonstrated that openings of the pressurizer manwey and the steam generator manway can prevent the core uncovery using only gravity feed injection. Although some disagreements are found in the detailed phenomena, the code prediction is considered reasonable for the overall system behaviors.

• Journal of Korean Philosophical Society
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• v.123
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• pp.57-86
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• 2012

Many contemporary philosophers argue that modern philosophy is only the philosophy being imprisoned in subject and consciousness without communicating other subjects with language. They criticize that it is solipsistic. Today, those who are taking part in the communication theory, hermeneutics, and de-constructivism are trying to overcome this problem. The practical philosophers, especially those who advocate communintarianism criticize that modern libertarianism is not free from the isolated autonomy and breaks the solidarity of the traditional community with treating formally others. They criticize Kant's philosophy in the same way. But it is unreasonable. Because Kant was not the philosopher who pursued the same philosophy of subjectivity and liberalism as the earlier modern philosophers pursued. He tried to criticize its limits and overcome them. Especially he did not remain within the modern subjectivity, but rather tried to come up with the inter-subjectivity communicating between subjects. He showed this side through the 'sensus communis'. He thought of a judgement of taste as an effect resulting from the free play between imagination and understanding, and postulated the 'sensus communis' as a ground of the universal validity of this judgement. Therefore this 'sensus communis' is the subjective principle of a judgement of taste. Furthermore, he did not treat this 'sensus communis' merely as a self-relation of a subject, but rather developed it into an communicative relation among subjects. This position of Kant enables us to seek the harmony between the aesthetic sphere and social-moral sphere, and to overcome the conflicts between the autonomy of the liberalism and the solidarity of the communitarianism. Especially, his 'sensus communis' can be developed into the 'critical hermeneutics' and the 'relational autonomy'. Therefore his 'sensus communis' has the possibility to overcome the negative points of the traditional community and the modern community, and to overcome the conflicts among the isolated selves occurring in today's society. Hence Kant's 'sensus communis' has still the important values in the contemporary philosophy, especially in the practical philosophy being now discussed over the relation between autonomy and solidarity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.6
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• pp.638-647
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• 2003

Triangular patches have been studied, both theoretically and experimentally. We feund that provided radiation characteristics similar to those of rectangular patches, but with smaller size. In this paper, we designed an equilateral triangular microstrip patch antenna using cavity model analysis. Then, in order to improve narrow bandwidth, we add capacitive gap and air gap. Capacitive gap is located with square shape beside feeding point on the patch, and air gap is inserted between substrate dielectric and ground plane to adjust probe inductance. The analysis of characteristics and effects of each component was performed by commercial simulation tool, Ensemble 5.0. Throughout the simulation and experiment, we found the possibility of bandwidth enhancement in triangular microstrip antenna.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.90-101
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• 2007

With increasing development of underground space, underground pumped storage power plants, which generate power by felling water in upper reservoir to lower reservoir, have been continuously constructed. For efficient and safe design, construction and maintenance or such power plants, it is very important to understand in-situ stress and the mechanical properties of the surrounding rock mass at the design stage. The power plant presented in this paper is under construction at a depth of $320{\sim}375m$. For stability evaluation of the structure, in-situ stress was measured by over-coring method. Also pressurementer test and a series or laboratory tests were performed to obtain the mechanical properties. Numerical analyses were conducted to check the efficiency of designed support patterns. The results showed that unstable areas occurred partly in the numerical model, and therefore supports were additionally applied. Finally complete stability was obtained and the following excavation has been operated successfully until now.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.87-100
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• 2014

Environmental problems and the shortage of natural resources are currently gathering more attention in Korea and international countries. With these problems, it is reported that most current domestic buildings are emitting approximately 138 million tons of greenhouse gas. According to a recent report from the investigation of Korean housing population, the total number of households is approximately 12.9 millions, and the apartments that were built more than 15 years ago amounted to 3.1 millions. This shows that the rates of old apartment housings are increasing. Therefore, it is necessary to consider the deteriorated facilities and environmental improvement. Also, the construction industry is benefited by improving these housings which may need either remodeling or reconstruction. Environmental friendly buildings are a rising consideration for remodeling and reconstruction projects; it helps to determine many business matters in construction. The main purpose of this research is to improve environmental condition in apartments with comparison analysis between remodeling and reconstruction alternatives. This research is focused on characteristics of remodeling and reconstruction and it sets up the same condition with each level in order to evaluate the value of environmental friendliness and analyze its definition. The result of this research provides a unique emitting rate at a novel framework and this will cause the reduction of $CO_2$. It is analyzed that the remodeling construction can reduce the great amount of $CO_2$. Therefore, it will be a good decision guideline in selecting the most eco-friendly alternative to improve environment for building construction. Although reconstruction is a popular alternative nowadays in Korea, this research can provide a reason why decision makers should put more emphasis on remodeling as an environment-friendly alternative.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.62-62
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• 2009

석탄화력발전소의 CO2배출량 감소와 고효율, 대용량화로 인해 초초임계압(USC:Ultra Super Critical) 화력발전소의 건설이 증가하고 있다. USC 발전소는 효율향상을 위한 증기온도와 압력의 상승 때문에 보일러 고온고압부에 기존의 소재에 비해 고온강도와 내산화성의 재료물성이 향상된 신소재 적용이 불가피하다. 특히 사용된 신소재 중에서 보일러 본체를 구성하는 수냉벽관(Water wall), 과열기와, 재열기용 튜브 및 후육부인 헤더와 배관재로 기존의 2.25Cr-1Mo강을 개량한 2.25Cr-1.6W계 내열강이 적용되고 있다. 2.25Cr-1.6W강은 SMI와 MHI가 공동개발한 소재로 1995년 튜브제품이, 1999년에 단조, 파이프재, 플레이트제품이 ASME code case로 등재되었고, 2009년 ASME code case 2199-4로 개정되어 사용 중이다. 이 소재는 2.25Cr-1Mo강에 고온강도 개선을 위해 석출강화효과가 있는 V과 Nb을 첨가하였고, 탄화물의 열적안정성과 고용강화효과 증대를 위해 W을 첨가하였다. 그리고 제작성과 용접성 및 재료의 인성 향상을 위해 B첨가와 C함량을 낮추었다. 합금성분의 첨가와 조정에 의해 고온강도는 개선되었지만, 보일러 설치 및 보수를 위한 용접과정에서 용접금속과 CGHAZ(Coarse Grain HAZ)에서 용접균열이 발생하였다. 대부분의 용접균열은 용접결함이나 고온 혹은 저온균열이 아닌 2.25Cr-1.6W계강의 강도 개선을 위해 첨가한 V과 Nb이 용접후열처리 도중 입내에 MX형태의 미세석출로 입내를 강화시킴으로서 발생한 재열균열 민감성 증대에 기인된 것으로 판단된다. 이에 본 연구에서 용접 및 후열처리 과정에서 용접금속과 HAZ에서 발생하는 용접금속의 응력분포를 전산해석을 통해 확인하고 실제 후육파이프 용접부에서 잔류응력을 측정해 비교하였다. 용접부 응력분포는 SYSWELD 프로그램을 사용해 해석을 수행하였고, 발전소 실배관재의 용접부 응력측정은 수평부 측정이 용이하도록 지그를 부착한 Potable 잔류응력측정기를 사용해 Hole Drilling Method(HDM)를 적용하여 잔류응력을 측정하였다. 해석 결과 CGHAZ부위의 잔류응력이 용접금속과 기타 부위에 비해 높은 응력분포를 나타냈으며, 이는 CGHAZ와 용접용융선 부근에서 균열이 발생하는 실제값과 일치하는 결과를 보였다. 실제 배관재 용접부에서 측정한 잔류응력값은 항복응력의 약 50% 이하 응력값을 나타냈다. 배관 구조에 기인한 시스템응력의 영향을 제거하기 위해 배관재 용접부를 중심으로 양끝단을 절단 후 용접부에서 측정한 응력은 항복응력 대비 25%수준의 낮은값을 보였다. 그러나 배관재가 장기간 고온환경에 노출되었고 용접금속 내부의 균열이 발생한 상태에서 측정하였기 때문에 용접잔류응력은 상당부분 해소되어 상대적으로 낮은 응력값이 얻어진 것으로 판단된다.

• Journal of the Korean Geophysical Society
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• v.6 no.3
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• pp.165-177
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• 2003

The purpose of this paper is to analyze the behavior and to study the safety evaluation of the Unmun Dam located in Cheongdo-Gun of GyeongBuk Province, Korea. For this purpose, soil analyses including boring data, geophysical surveys were conducted. In this paper, especially many geophysical methods were adopted to configure out the subsurface situation of dam. Applied geophysical methods were: 1) electric resistivity survey, 2) high frequency magnetotelluric (HFMT) survey, 3) ground penetrating radar (GPR) survey, 4) seismic refraction survey, 5) seismic cross-hole tomography survey, and 6) high frequency impedance (ZHF) survey. Each of geophysical surveys were analyzed and joint analyses between geophysical surveys were also performed to deduce the more reliable subsurface information of Dam by using the features and characteristics of each geophysical survey. Since many defects, such as gravel and weathered rock blocks in the dam core, and lots of amounts of leakage, by boring analyses were found, reinforcement by compaction grouting system (CGS) has been conducted in some range of dam. Some geophysical data and data of geotechnical gauges were also used to confirm the effects of reinforcement. Electric resistivity, EM, GPR, ZHF, seismic refraction and seismic tomography surveys show that left side of dam is weak, which means the possibility of existence of gravel, rock block, water and cavities in the core of dam. This result coincides with the boring data. Especially, electric survey after reinforcement shows that even the right side of the dam has been deformed by the strong pressure during the reinforcement itself. As a conclusion, some problems in the dam found. Especially, the dam near spillway shows the high possibility of leakage. It should be pointed out that only the left side of he dam has not a leakage problem. As a whole, the dam has problems of weakness, because of unsatisfactory construction. It is strongly recommended that highly intensive monitoring is required.

• The Korean Journal of Air & Space Law and Policy
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• v.5
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• pp.265-301
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• 1993

지난 6월 3일 동경에서 있었던, 아시아 항공/우주법 학술대회 제 3분과에서 영국 Bin Cheng교수의 "The Warsaw System: Mess up, Tear up, or Shore up?"이라는 주제의 논문발표가 있었다. Bin Cheng교수는 특히 유럽의 EC Consultant Paper 와 일본항공사들의 1992년의 무한책임보상주의 채택에 대하여, 마치 무한 책임보상주의의 이론이 승리하였으며, 위의 상황들이 그 시작이라고 단정하였는데 이러한 견해는 아직까지 시기상조라고 생각한다. 본 글에서는 동경회의에서의 Bin Cheng교수의 논문중 특히 10항의 결론 부분을 중점으로 반대되는 의견을 제시하고자 한다. 국제항공사법인 와르소체제가 과연 발전하고 있는 것인가? 퇴보하고 있는 것인가? 와르소체제의 반대론자들은 미국의 소송변호사들, 일본항공사들과 일부 순수이론을 고수하는 학자들로써 이들은 와르소체제로부터의 탈퇴와 무한책임보상주의를 고수하고 있다. EC Consultation Paper (각주 122 참조)에서 보듯이, 비록 항공운송시의 손해배상액이 타 운송시의 손해배상액보다 적기는 하지만 이것이 곧 '무한책임보상주의'를 의미하는 것은 아니다. 미국의 판례중 불법행위로 인한 소송 (Nichole Fortman v. Hemeo Inc.)에서 보면, 작은 창자의 대부분을 병원의 과실때문에 잃은 Brooklin의 한 여인에게 500억 정도의 손해배상이 주어진 것을 보면, 과연 완전 보상에 맞는 무한책임이 과연 항공소송에 적용될 수 있는 것인가를 알아야 한다. 무한책임보상주의는 특히 개발도상국의 항공사들에게 보험료가 너무 과중하고, 와르소협약의 근본목적인 국제항공법의 통일성에 반하고 있기 때문에 국제사회 전반에 적용하기에는 비현실적이다. 와르소체제의 통일 성에 대한 거부는 만약 와르소체제에 버금가는 다른 보상체제가 있는 경우에는 다르지만, 현실적으로는 결국 국제적 혼란만을 야기사킬 것이다. 또한 와르소체제 반대자들은 항공운송인과 승객들의 관계를 갈등관계로 보고 있지만, 근본적으로 와프소협약에서의 항공운송인파 승객들의 관제는 공동이악관계로 보아야 한다. 항공운송사업의 목적도 또한 이윤추구인 바, 승객들이 항공운송인에게 과다한 손해배상을 요구하면, 결국 항공운송인은 승객들의 주머니에서 그 댓가를 찾으려고 할 것이다. 절국 양자의 이익을 보는 것은 소송변호사들 뿐이라고 볼 수 있다. 또한 'Unlimited Liability' 에서 'Unlimited' 란 'Full-Compensation' 을 의미하는 것으로, 'Wilful-Misconduct' 의 경우에는, 'Full-Compensation' 의 개념과 다르게, 그 보상액이 Warsaw협약 제 22조 1항에 적용되지 않는 'No-limited' 의 개념으로 해석하여야 한다. 항공소송의 경우에 통상 'Wilful-Misconduct' 의 경우에 손해배상액이 약 $700,000 인 것을 보더라도 'Full-Compensation'의 의미로 해석할 수 없다. 몬트리올 제 3추가의정서에서 'WilfulMisconduct' 의 개념을 삭제하고자 하는 것은, 이에 대비하여 추가보상제도, 임액수의 종액, 영격책임추의 등의 요소들을 전제로 하고 있기 때문이다. 몬트리올 제 3추가의정서가 최근의 발전적인 손해배상제도인가에 대하여, Bin Cheng 교수는 반대를 하고 있지만, 최선의 제도를 찾는 입장에서 몬트리올 추가 의정서는 여러가지로 부족하다. 그러나, 유한책임제도의 개선, 엄격책임주의의 도입, 빠른 소송타결의 제도, 재판관할권의 확대 그리고, SDR 화폐단위의 채택 등은 헤이그 의정서 이후의 보다 나은 제도적 장치를 하고 있다고 해석하여야 할 것이다. 시대의 변화에 따라 점진적으로 발전된 보상제도를 채택하였다면, 오늘날과 같이 시대에 뒤떨어진 보상체제로 혼란을 겪고 있지 않았을 것이다.

• Convergence Security Journal
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• v.11 no.5
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• pp.41-51
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• 2011

The objective of this study is to generally check the present situation of private security industry by analyzing the current situation of private security industry in Korea so as to find which policy base is reflected to amend law by analyzing the amendment process of private security law in order to suggest policy direction of private security industry in Korea. Viewing through amendment process of private security law, enhancing publicity and enterprise are not judged to form any definite policy base. They are merely interpreted to partially reflect enterprise under the strong base of publicity. Such policy base may cause overall stagnation of private security industry. For sound development of private security industry, it is required to get out of the existing policy direction so as to change policy base to the direction of enhancing enterprise of private security industry. The power of police for instruction and supervision should be largely transferred to Korea Security Association so as to cultivate autonomous purifying function of private security industry. Police should strive to develop policy in the level of joint production of security service.