• ETRI Journal
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• 제21권1호
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• pp.1-27
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• 1999

We present a new description of envelope-function equation of the superlattice (SL). The SL wave function and corresponding effective-mass equation are formulated in terms of a linear combination of Bloch states of the constituent material with smaller band gap. In this envelope-function formalism, we review the fundamental concept on the motion of a wave packet in the SL structure subjected to steady and uniform electric fields F. The review confirms that the average of SL crystal momentums K = ($k_x,k_y,q$), where ($K_x,k_y$) are bulk inplane wave vectors and q SL wave vector, included in a wave packet satisfies the equation of motion = $_0+Ft/h$; and that the velocity and acceleration theorems provide the same type of group velocity and definition of the effective mass tensor, respectively, as in the Bulk. Finally, Schlosser and Marcus's method for the band theory of metals has been by Altarelli to include the interface-matching condition in the variational calculation for the SL structure in the multi-band envelope-function approximation. We re-examine this procedure more thoroughly and present variational equations in both general and reduced forms for SLs, which agrees in form with the proposed envelope-function formalism. As an illustration of the application of the present work and also for a brief investigation of effects of band-parameter difference on the subband energy structure, we calculate by the proposed variational method energies of non-strained $GaAs/Al_{0.32}Ga_{0.68}As$ and strained $In_{0.63}Ga_{0.37}As/In_{0.73}Ga_{0.27}As_{0.58}P_{0.42}SLs$ with well/barrier widths of $60{\AA}/500{\AA}$ and 30${\AA}/30{\AA}$, respectively.

• 한국발생생물학회지:발생과생식
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• 제2권2호
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• pp.141-148
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• 1998

돌고기 Pungtungia herzi 정자의 미세구조를 주사 및 투과 전자현미경적 방법으로 연구하였다. 정자는 구형의 두부, 짧은 중편 및 꼬리로 구성되어 있으며 비교적 그 구조가 단순하고 그 길이는 약 37.4$mu extrm{m}$이었다. 정자의 미세구조에서 핵에 대한 접선 방향으로의 편모 배열, 짧은 핵 그리고 미토콘드리아의 비대칭적 배열은 잉어과 정자의 공통된 특징과 마찬가지로 나타났으며, 대부분의 경골어류에서와 같이 첨체를 가지고 있지 않았다. 반면 돌고기 정자에서는 핵막의 구조와 미토콘드리아에서 현저한 특징을 나타내었다. 핵막은 매우 심하게 파동되어 있으며 얕은 핵와내의 기부 및 말단중심립은 약 130$^{\circ}$의 각도로 배열되어 있었다. 미토콘드리아는 제 1 정모세포기에 5개 이상 관찰되었으나 성숙한 정자에서는 하나의 형태로 융합되어 있었다. 이러한 양상은 융합되지 않은 다른 잉어류 정자에서의 미토콘드리아와 비교할 때 현저한 차이가 있었다. 정자의 계통 진화적 견지에서, 돌고기에서와 같이 융합된 미토콘드리아는 융합되지 않고 분리되어 있는 미토콘드리아에 비해 원거리 형질(apomorphic character)로 간주된다. 한 개의 미토콘드리아를 가지는 정자는 현재까지 Rhodeus 이외의 다른 잉어류 정자에서는 보고된 바 없었다.

• 한국디지털건축인테리어학회논문집
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• 제10권1호
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• pp.15-22
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• 2010

As for structural system, which constitutes his construction, there are column inside dimension and span which constitutes plane, and as for constructions for section, there are C.H and slab, and as for constructive factors for envelope, there are window and closing panel of outer wall, and as for opening, there are punching window and wave window. With these constructive parts and opening of envelope, his construction composes volume and mass. The relation of structure and modulor which are shown in his later construction can be divided in two cases that modulor is directly and indirectly adapted for rate and measure calculation of the constructive body. As for indirectly adapted case, we can find it form most of his later construction, it is living place in which human beings life is, and it is adapted mainly for small space. In his construction, he tried to tell human scale and sense of musical rhythm through modulor. In other words, he played sense of space and musical scale by adapting regular and repetitive modulor of opening, and in small space for daily life, he made the size of space into the space which human can perceive. And, if we interpret mudulor in modern meaning, it is an establishment of radius of human act. And, we can make organic and harmonic design of space if we use modulor as origin of human centered measurement calculation, and if we adapt space after dividing by use.

• 한국건설관리학회논문집
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• 제14권4호
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• pp.84-96
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• 2013

최근 건설 산업의 디지털화로 인하여 건축 디자인이 정형에서 자유로운 비정형 형태로 변화하고 있다. 특히, 국내에서는 최근 비정형이 디자인 경향으로 도입되어 현상설계, 턴키 등에서 설계 당선을 위한 디자인 요소로 많이 적용되고 있다. 그러나 기존의 정형 건축물의 외벽공법을 비정형 건축물의 외피에 그대로 적용함으로써 누수 및 크랙 등 다양한 하자가 발생하고 있다. 이러한 문제점을 개선하고 공사기간과 공사비를 최소화할 수 있는 비정형 건축물의 설계와 시공이 새로운 기술로 도입되고 있다. 이에 본 연구는 비정형 외피시스템 구현을 위한 공법을 국내외 비정형 건축물의 외피시스템 사례 분석을 통하여 실증적으로 시사점을 도출하고 비정형 건축물 외피시스템의 설계와 시공시 고려해야 할 사항을 다음과 같이 제시하였다. 첫째, 시공성을 고려한 비정형 형태의 설계가 되도록 하여야 한다. 둘째, 2방향 곡면을 정확히 구현할 수 있는 단위 패널 생산 기술의 개발이 필요하다. 셋째, 비정형 콘크리트 외피용 노출 콘크리트 거푸집을 개발하여야 한다. 넷째, 외피 시스템을 부위별로 구분하여 우수처리와 방수를 위한 재료와 공법 특성과 유지관리 방안을 고려하여야 한다.

• 한국CDE학회논문집
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• 제15권2호
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• pp.106-114
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• 2010

The swept volume, the region of a moving object, is applied in many fields such as valid paths for motions of tools, visualization in robot paths and interference tests for parts assembling or disjointing. The shape of a swept volume depends on an generators computed with normal vectors of an object and velocity vectors of a motion. Although free-from surfaces are widely used to represent geometric models in CAD, computing the generators for a free-form object is a formidable task. Previous approaches exploit the closed form expressions of generators but limited to planer or quadric faces. In this paper, we propose the algorithm to compute swept volumes generated by free-form objects in screw motions. For the algorithm a tracing method is applied to the computation of generators. It considers curvatures of surfaces of an object to increase the computational accuracy. We implemented our algorithm in the CATIA V.5 environment to test the validity of our algorithm and to generate examples.

• 한국어류학회지
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• 제26권3호
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• pp.179-184
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• 2014

잉어과(Pisces, Cyprinidae)에 속하는 멸종위기 어류인 돌상어 Gobiobotia brevibarba의 난막미세구조 및 난자형성과정을 광학현미경과 주사전자현미경을 이용하여 관찰하였다. 2014년 5월의 돌상어 난소 내에는 다양한 발생단계의 생식세포들이 관찰되었다. 난모세포들의 상대면적은 성숙란(74.5%), 난황물질이 형성되는 난황구기(16.6%), 난황포기(6.6%), 그리고 미숙한 발달단계인 주변인기(2.3%) 순으로 구성되어 있었다. 주변인기 단계의 세포질은 hematoxylin에 강하게 염색되며, 핵막의 안쪽에는 다수의 인들이 존재하였다. 난황형성물질인 난황포기와 초기 난황구기 단계에서는 여포층과 방사대가 뚜렷하게 형성되기 시작되었으며, 방사대 위에는 미세융모의 난막구조가 더욱 뚜렷해졌다. 난황구기 및 성숙란의 단계에서는 난황구 일부가 융합되면서 강한 호산성을 보였다. 또한 성숙란의 표면에는 깔때기 모양의 난문이 관찰되었으며, $2{\sim}3{\mu}m$ 길이의 미세융모가 일정하게 분포하였다.

• 터널과지하공간
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• 제28권5호
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• pp.426-441
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• 2018

일반화된 Hoek-Brown (GHB) 파괴조건식은 최근 각종 암반공학적 계산에 활발히 이용되고 있지만 Mohr 파괴포락선이 해석적 수식으로 표시되지 않아 적용범위를 넓히는데 어려움이 있다. 이러한 단점을 극복하기 위해 이 연구에서는 GHB 파괴함수에 내포된 수직응력 - 접선마찰각 관계식을 다항식으로 최적 근사시켜 접선마찰각을 수직응력의 명시적 근사함수로 표시하는 새로운 방법을 제안하였다. 이 수직응력 - 접선마찰각 관계식을 직선 또는 2차 다항식으로 최적 근사시킬 경우 접선마찰각에 대한 해석적 해가 존재한다. 이 해를 전단응력 - 접선마찰각 관계식에 대입하면 GHB 파괴함수의 근사적 Mohr 파괴 포락선을 유도하는 것이 가능하다. 유도한 근사 Mohr 파괴포락선은 GSI 값 전체 범위에서 정해와 매우 근사함이 입증되었다.

• Architectural research
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• 제1권1호
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• pp.31-40
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• 1999

In this age of "Information", many people consider it a deterrent to information flow to provide a hierarchy with private rooms in a modern office layout. There are others, however, who insist that visual and acoustical privacy are more important than any other design factor in achieving higher productivity. The debate may never end, but the partitioned open plan, which is a new form of the vast open plan, has merits of each concept - open and closed layout. Consequently, office design has dramatically shifted to partitioned open planning, with shorter, temporary walls or partitions, originally intended for increasing privacy and diminishing hierarchy, yet still keeping flexibility in spatial organization. The introduction of low-level partitioned spaces in an office layout, however, produces a complicated lighting design problem. Obviously, accurately predicted daylighting performance data are needed not only for daylighting design but for artificial lighting system design. Scale models of 12 sets of unit partitioned spaces are constructed and extensive scale model measurements of both daylight and reflected sunlight have been performed within an artificial sky simulator. The prototype-building interior is modeled with different partition configurations, each of which is modeled using the different envelope geometry and exterior configurations, and then the variations in interior light levels are estimated. The result indicates that partitioned spaces employed in an open plan of modern offices still offer a large potential for daylighting and energy saving as well. Much of the savings may derive from the cumulative effect of reflected sunlight. Optimal design for building envelope geometry and exterior configuration promises additional savings.

• Journal of Microbiology
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• 제34권1호
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• pp.7-14
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• 1996

Teh baculovirus gp64 glycoprotein is a major component of the envelope of budded virus (BV) and has been shown that it plays an essential role in the infection process, especially virus-cell membrane fusion. We have cloned Autographa californica Nuclear Polyhedrosis Virus (AcNPV) gp64 protein were examined for membrane fusion activity by using a synchtium formation assay under various conditions. The optimal conditions required for inducing membrane fusion are 1) form pH 4.0 to 4.8 2) 15 min exposure of cells to acidic pH 3) at least 1 .mu.g of gp64 cloned plasmid DNA per 3 * 10$^{6}$ cells 4) and an exposure of cells to acidic pH at 72 h post-transfection. In order to investigate the role of hydrophobicity of the gp64 glycoprotein for the membrane fusion, the two leucine residues (amino acid position at 229 and 230) within hydrophobic region I were substituted to alanine by PCR-derived site-directed mutagenisis and the membrane fusion activity of the mutant was anlaysed. The gp64 glycoprotein carrying double alamine substitution mutation showed no significant difference in fusion activity. This result suggested that minor changes in hydrophobicity at the amino acid position 229 and 230 does not affect the acid-induced membrane fusion activity of the gp64 glycoprotein.

• Journal of Microbiology
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• 제35권1호
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• pp.72-77
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• 1997

The baculovirus gp64 glycoprotein is a major component of the envelope protein of budded virus (BV). It has been shown that the gp64 glycoprotein plays an essential role in the infection process, especialy fusion between virus envelope and cellular endosomic membrane. Recently we reported optimal conditions required for gp64-mediated membrane fusion in pGP64 DNA transfected Spodoptera frugiperda (Sf9) cells (H. J. Kim and J. M. Yang, Jour, Microbiology, 34.7-14). In order to investigate the role of hydrophobicity within the fusion domain of the gp64 glycoprotein for membrane fusion, 13 mutants which have substitution mutation within hydrophobic region I were constructed by PCR-derived site-derected mutagenesis. Each mutated gp64 glycoproteins was transiently expressed by transfecting plasmid DNA into Spodoptera frugiperda (Sf9) cells. Oligomerization of the transisently expressed gp64 glycoproteins was a nalysed by running them on SDS-polyacrylamide gel electrophoresis under non-reducing condition followed by immunoblotting. All of the mutant gp64 glycoproteins expect cysteine-228 were able to form trimers. These results suggest that hydrophobic region I of the gp64 may not be responsible for the oligomerization of the gp64 glycoprotein.