• 한국분말재료학회지
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• 제29권6호
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• pp.517-522
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• 2022

We investigate the austenite stability in nanocrystalline Fe-7%Mn-X%Mo (X = 0, 1, and 2) alloys fabricated by spark plasma sintering. Mo is known as a ferrite stabilizing element, whereas Mn is an austenite stabilizing element, and many studies have focused on the effect of Mn addition on austenite stability. Herein, the volume fraction of austenite in nanocrystalline Fe-7%Mn alloys with different Mo contents is measured using X-ray diffraction. Using a disk compressive test, austenite in Fe-Mn-Mo alloys is confirmed to transform into strain-induced martensite during plastic deformation by a disk d. The variation in austenite stability in response to the addition of Mo is quantitatively evaluated by comparing the k-parameters of the kinetic equation for the strain-induced martensite transformation.

• International Journal of Korean Welding Society
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• 제3권1호
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• pp.39-44
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• 2003

The welded specimens were made by butt welding of the 2 wires of 50mm length using the pulsed YAG laser. The laser welded wires were tested for investigating the shape memory effect and the ability of super elasticity. The fatigue properties of the welded wires were investigated using the rotary bending fatigue tester specially designed for wires. Moreover, the effect of defocusing distance during laser welding on the static and fatigue properties was Investigated. The shape memory effect and super elasticity of the laser welded wires were approximately identical with that of base metal at the test temperature below 353K. However, the welded wires were broken within elastic limit at the test temperature above 353k. Under the cyclic bending loading conditions, the welded wires could be useful only below the elastic limit, while the base metal had sufficient fatigue life even the stress induced M-phase region. The fatigue strength of the welded wires was about half of that of the base metal. The deterioration of the static and fatigue properties in the welded wires was proven to be from the large difference of the transformation behavior between the base metal and welded part that is caused by vaporization of Ni-content at the welded part during the welding process. The defocusing distance below 3mm acted more largely on lowering the strength of the welded wires than that of 6mm or 8mm.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.88-92
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• 2011

Even though attempts are made to transform from 2D CAD to BIM representation for building design and construction, it were not so successful for practical implementation until recently in construction industry in Korea. However, there is a dramatic change for the use of BIM by collaboration among government, independent organizations as well as industry itself. Government reckons that BIM is an important tool for environment friendly construction and industry competitiveness. The government not only makes national BIM standards and push policies in order to make market environment. Independent organizations such as BuildingSMART Korea does active role to stimulate the transformation process successfully. They act as opinion leaders for the Government to consider BIM implementation for industry competitiveness issue. They make roadmap as well as technical standards and guidelines. It also leads technical developments and supports for its implementation. Government supports researches for the implementation of BIM. The research includes BIM standards, guidelines, linking with existing Architectural Administrative Information Systems, making libraries as well as education. Government makes policy for BIM as a compulsory data for bidding process of newly designed government buildings. Private sector not only agrees BIM as a tool to adapt but also essential methods for its survival in domestic and foreign construction market. Architectural design companies and constructions companies currently develop technical skills and implement BIM for new projects such as Dongdaemoon Plaza that cannot be successfully drawn by conventional methods.

• 전자공학회논문지
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• 제52권9호
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• pp.89-95
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• 2015

본 논문에서는 비전 기술을 기반으로 원거리에서 2차원 바코드를 검출 할 수 있는 실시간 시스템을 제안한다. 제안된 시스템은 2차원 바코드의 위치 심볼을 찾는 근거리 검출을 먼저 수행하고, 만약 검출이 안 될 경우 원거리 검출로 전환된다. 원거리 검출은 다음과 같은 순서로 진행된다. 먼저 에지 지도, 영상 이진화, CCL(connect component labeling)을 순차적으로 수행하여 관심 영역을 설정한다. 설정된 관심 영역을 Bilinear Interpolation을 이용하여 확대한 후, 근거리 검출과 마찬가지로 위치 심볼 패턴을 검출하여 2차원 바코드 영역을 결정한다. 마지막으로 검출된 패턴 정보를 활용하여 역 투영 변환을 적용하여 패턴을 정렬하게 된다. 실험 결과 제안된 시스템은 기존에 제안된 2차원 검출 알고리즘보다 약 2~3배정도 더 먼 거리의 바코드를 검출 할 수 있음을 보였고, 여러 개의 2차원 바코드 검출이 가능함을 보였다. 또한, 실내의 복잡한 환경에서도 강인한 검출 결과를 보였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권4호
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• pp.37-48
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• 2022

Accurate analysis of petroleum hydrocarbons in soil is an important prerequisite for proper source tracking of contamination. Identification of petroleum compounds is commonly carried out by peak pattern matching in gas chromatography. However, this method has several technical limitations, especially when the soils underwent biological, physical and chemical transformation. For instance, it is very difficult to distinguish jet fuel (JP-8) from kerosene because JP-8 is derivatized from secondary reaction between chemical agents (e.g. anti-oxidants, antifreezer and so on) and kerosene. In this study, an alternative method to separately analyze JP-8 and kerosene in the petroleum hydrocarbon contaminated soil was proposed. Qualitative analyses were performed for representative phenolic antioxidants [2,6-di-tert-butyl phenol (2,6-DTBP), 2,4-di-tert- butylphenol(2,4-DTBP), 2,6-di-tert-butyl-4-methyl phenol (2,6-DTBMP)] using a two dimensional gas chromatograph mass spectrometer (2D GC×GC-TOF-MS). This qualitative analysis of antioxidants in soil would be a useful complementary tool for the peak pattern matching method to identify JP-8 contamination in soil.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5148-5154
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• 2012

본 논문은 포환던지기 여자 기록보유자의 실제 경기에서 포환과 신체 무게중심의 운동학적 특성을 분석하는데 있다. 이를 위해 2대의 비디오카메라를 이용하여 촬영 한 후, 3차원 영상분석을 위해 DLT 방법을 이용하였으며, 자료 분석을 위해 Kwon3D 프로그램을 이용하였다. 그 결과는 다음과 같다. 첫째, 포환의 투사 속도와 투사 높이는 각각 13.73 m/s, 198.6 cm(신장비 119%)로 선행연구들과 비교했을 때, 최적의 수행을 한 것으로 판단되나 투사 각도는 $34^{\circ}$로 다소 작게 나타났다. 둘째, 신체 무게중심의 이동은 글라이드 구간에서 투사 방향으로의 이동이 필요하며, 딜리버리 구간에서 신체 무게중심의 상하 이동을 제어해야 한다. 셋째, 릴리즈 순간 신체 무게중심의 좌우방향과 상하방향의 흔들림 없이 정확한 타이밍에 포환이 투사되어야 한다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.51-54
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• 2005

Shape memory alloys (SMAs) find many applications in smart composite structural systems as the active components. Their ability to provide a high force and large displacement makes them an excellent candidate for an actuator for controlling the shape of smart structures. In this paper, using a macroscopic model that captures the thermo-mechanical behaviors and the two-way shape memory effect (TWSME) of SMAs smart morphing polymeric composite shell structures like shape-changeable UAV wings is demonstrated and analyzed numerically and experimentally when subjected to various kinds of pressure loads. The controllable shapes of the morphing shells to that thin SMA strip actuator are attached are investigated depending on various phase transformation temperatures. SMA strips start to transform from the martensitic into the austenitic state upon actuation through resistive heating, simultaneously recover the prestrain, and thus cause the shell structures to deform three dimensionally. The behaviors of composite shells attached with SMA strip actuators are analyzed using the finite element methods and 3-D constitutive equations of SMAs. Several morphing composite shell structures are fabricated and their experimental shape changes depending on temperatures are compared to the numerical results. That two results show good correlations indicates the finite element analysis and 3-D constitutive equations are accurate enough to utilize them for the design of smart composite shell structures for various applications.

• Journal of Plant Biology
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• 제38권2호
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• pp.203-209
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• 1995

담배(Nicotiana tobacum L. cv. Wisconsine 38) 잎 절편을 해녀콩(Canavalia lineata)의 leghemoglobin(Lb) cDNA를 포함하는 Agrobacterium과 함께 배양한 후, 0.5mg/L BAP, 0.1mg/L ${\alpha}-NAA$와 200mg/L kanamycin, 500 mg/L carbenicillin을 포함하는 MS 배지에서 선별하여 7개의 재분화 개체를 얻었다. 이로부터 분리한 게놈 DNA에 대한 Southern 혼성화 반응과 PCR 결과로 Lb cDNA가 담배의 게놈에 삽입되었음을 확인하였다. 형질전환된 담배로부터 분리한 RNA에 대한 northern 혼성환 실험 결과 약 1,000 nt의 RNA가 혼성화 반응을 보였으며, 총 RNA를 주형으로 합성한 1차 가닥의 cDNA를 PCR로 증폭한 결과, Lb cDNA와 혼성화 반응을 보이는 0.5 kb의 DNA가 증폭되었다. 콩의 Lb에 대한 다군항체(polyclonal antibody)를 사용하여 단백질 면역 항체 반응을 실시한 결과, Lb로 판단되는 약 15.8 kD의 위치에서 혼성화 반응이 나타났다. 이상의 결과로 해녀콩 Lb cDNA가 형질전환된 담배의 게놈에 삽입되었을 뿐만 아니라 mRNA로 전사되어 Lb 단백질로 해독되었음을 알 수 있었다.

• 미생물학회지
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• 제31권1호
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• pp.93-98
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• 1993

수계생태계에서 유기물질의 순환을 이해하기 위하여 팔당호에서 종속영양 활성도와 세균세포의 효소활성의 계절절 변화를 연구하였다. 팔당호 I 의 glucose 전환시간은 수층, 퇴적토에서 2-1,300 시간, 17-170 시간, protein hydrolysate 는 5-900 시간, 15-240 시간, acetic acid 는 4-350 시간, 15-230 시간으로 계절적인 변화를 나타냈다. Glucose, protein hydrolysate, acetate 각각의 호흡율은 수층에서 23-32%, 38-41%, 22-28%로 나타났고 퇴적토에서는 34%, 61% and 41% 로 나타났다. 이 결과로 3가지 유기물질 종류 모두가 수층보다 퇴적토에서는 높은 율로 호흡됨을 알 수 있었다. 한편 세균의 $\alpha$-glucosidase, $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase, aminopeptidase 활성력을 살펴본 결과 수층에서는 효소 각각에 대해 32-44%, 31-32%, 18-34% 61-67% 의 범위를 나타내었고 퇴적토에서는 34%, 40%, 23% 65%로 나타났다.

• 한국가구학회지
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• 제19권4호
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• pp.260-272
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• 2008

The recent concept of kitchen is likely defined as "Kitchen Culture" including the function of living room where all families make a conversation as well as a dinner, and it is becoming another type of the residential environment, deviating from the stereotype as only cooking area. Particularly the comfortableness of living room is closely associated with a receipt function of kitchen, and the sort & dimension & size of furniture and diversity of shapes playa more meaningful role for improving our life standard & comfortableness compared with the past, nevertheless this receipt study is carelessly handled in the first phase of construction. This Study is focusing on understanding the modern concept of kitchen where the open space concept is being introduced as more reasonable space concept, and on suggesting a solution for receipt-function of the modern kitchen concept connected with "L-D-K (Living room - Dining room- Kitchen)" space idea. In the Chapter 2 the concept of receipt and function of kitchen, the wide variety of kitchen utensils was checked up, and in the Chapter 3 the change of trends of kitchen area & receipt space was considered, and finally in the Chapter 4 the modern concept of kitchen was presented, by instancing overseas examples with receipt planning. As a consequence, the alternative of the receipt in the modern kitchen is to install an Ireland table or another type of receipt-available table (lower furniture) in the dead space between kitchen & living room for motivating smooth communication and convenient receipt, and that is the trend nowadays. Kitchen desires a rapid change. Through this kind of study it should be more researched that kitchen is not an independent space any more and lies in the mutual connection of L-D-K.