• 환경생물
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• 제41권3호
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• pp.298-307
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• 2023

이 연구에서는 우리나라 서해안에 서식하는 쏙 (U. major)과 가시이마쏙(A. wuhsienweni) 암컷의 연중 번식 주기를 조직학적 방법을 이용하여 조사하였다. 채집된 시료는 연령에 따른 성숙 및 번식생태 차이가 있는지 알아보기 위해 두흉갑장(carapace length, CL)을 기준으로 성체와 어린 개체로 구분하여 분석하였다. 두흉갑장 25 mm 미만의 어린 쏙(U. major)의 경우에는 생식소 발달단계가 대부분 연중으로 초기발달기(62~100%)와 후기발달기(10~38%)로 관찰되어 번식에 참여하지 않는 것으로 확인된 반면, 두흉갑장 25 mm 이상의 성체 쏙의 경우에는 뚜렷한 계절적 변화 패턴이 관찰되었다. 성체 쏙의 생식소 발달단계는 11월에서 이듬해 3월까지 초기발달기와 후기발달기가 관찰되고, 완숙기의 성숙난은 4월부터 10월까지 관찰되었다. 두흉갑장 15 mm 이상 가시이마쏙 성체의 경우에는 생식소 내 완숙된 성숙난이 연중 관찰되었으며, 완숙기는 1월부터 6월까지로 관찰되었다. 반면, 두흉갑장 15 mm 이하 어린 가시이마쏙의 경우에는 연중 미성숙 상태를 유지하였다. 우리나라에 서식하는 두 종의 쏙류는 암컷 성체의 생식소 성숙기간이 다른 것으로 조사되었으며, 또한 외포란 시기도 쏙은 월에서 4월, 가시이마쏙은 6월에서 9월로 전혀 다른 성 성숙 주기를 지닌 것으로 확인되었다. 이 연구는 조직학적 방법을 이용한 국내 서식 쏙류의 번식 주기를 최초로 구명한 연구로 쏙류의 생리생태를 이해하는데 중요한 기초자료로 활용될 것으로 기대되며, 패류 양식장 내 쏙류의 구제 방안 도출을 위한 기초자료로 활용될 것으로 기대된다.

• 대한건축학회논문집:계획계
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• 제35권3호
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• pp.91-102
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• 2019

This study explores the causes and processes of morphological transformation of apartment complexes in Busan. All apartment complexes built until the year 2016 were selected for statistical analysis, drawing/map examination, field observation, selected expert interviews based on 6 periodical groups: Period I(~1990), Period II(1991~1995), Period III(1996~2000), Period IV(2001~2005), Period V(2006~2010), and Period VI(2011~2016). The research argues for three 'arrangement' types, P1U, L1U and P2U, which have dominated the whole periods occupying 88% of the total 260 complexes. The switch of the leading type represents for morphological transformation of apartment complexes. Four aspects, density(F.A.R.), height(maximum number of floors), deformed-building-type ratio, and building-orientation, have affected the change of 'arrangement' types. Density was the major cause of the arrangement-type switch, from P1U to L1U, on Period II(1991~1995). The morphological change, from type L1U to P2U, on Period V(2006~2010) was caused by height and orientation, and is correlated with the increased number of deformed-type buildings. The first phase morphological change on Period II(1991~1995) was resulted by the supply side of apartment. However, the second phase transformation on Period V(2006~2010) had gone through the complex process including reflection of consumers' demands. The significance of research is to reveal the morphological transformation process of apartment complexes through analytical investigation of the entire apartment data in Busan. The result shows that the major change of urban paysage started to occur from Period V(2006~2010), and the superficial evaluation on apartment 'being monotonous and repetitive' may not be proper at least from the perspective of town plan.

• 대한의용생체공학회:의공학회지
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• 제7권2호
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• pp.113-116
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• 1986

We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4327-4331
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• 2011

A new method in thermal ionization mass spectrometry (TIMS) was developed to correct peak tailing backgrounds in the isotope ratio measurements of uranium in ultra trace levels for higher accuracy. Two different uranium standard reference materials (U005 and U030) were used to construct databases of signal intensities at mass 234 u and mass 236 u, which correspond to the two uranium minor isotopes, and signal intensity of $^{238}U$. Correlations between peak tailing backgrounds and $^{238}U$ were obtained by least-squares regression on calculated backgrounds at mass 234 u and mass 236 u with respect to the signal intensity of $^{238}U$ followed by separation of the peak tails of the two major isotopes of uranium ($^{235}U$ and $^{238}U$), which enables us to obtain a master equation for peak tailing background correction on all kinds of samples. Verification of the correction method was carried out using U010 and IRMM-040a.

• 통합자연과학논문집
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• 제16권2호
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• pp.47-51
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• 2023

Ras small GTPases are involved in regulating various cellular signaling pathways including cell migration, proliferation, and differentiation. Ras GTPase subfamily is comprised of 15 proteins; 11 Ras, 3 Rap, and one Rheb related protein. Some Ras proteins, such as RasC and RasG, have been identified for their major functions, but there are proteins whose functions have not been studied yet, such as RasU and RasX. Here, we investigated the roles of RasU in cell motility and development. RasU shows the highest homology with RasX. To investigate the functions of RasU, rasU null cells were used to observe the phenotype. Cells lacking RasU were larger and more spread than wild-type cells. These results indicate that RasU plays a negative role in cell spreading. In addition, we investigated the roles of RasU in cell motility and development of Dictyostelium cells and found that rasU null cells exhibited decreased random migration speed and delayed developmental process. These results suggest that RasU plays an important role in cell motility and development.

• 대한치과의사협회지
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• 제22권11호통권186호
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• pp.947-951
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• 1984

The present study was performed to establish the cephalometric standards of linear measurements in Hellman dental age II C groups of Korean on the roentgenocephalometry. The subjects consisted of 21 males 31 females with normal occlusion and acceptable profile. The major conclusions were as follows. 1. The means and standard deviations of the measurements in males and females were made. 2. No sex difference was made in all items, except in U₁-Y and U₁-X.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.321-326
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• 1996

During the plant operation, steam generator U-tube assembly will potentially be subject to adverse environmental conditions which can cause damages to them. This report addresses the major design factors of CANDU type steam generator which are intended to minimize the potential tube damages. Such factors include U-tube material, high circulation ratio, tube-to-tubesheet joint, tube support design. Also a few suggestions are presented for the design and performance improvement of CANDU type steam generators.

• 한국국방경영분석학회지
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• 제28권2호
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• pp.116-124
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• 2002

In just-in-time production systems, U-shaped production lines rather than traditional straight lines are often adopted since they have some advantages. The advantages of U-lines over straight lines are that the workstations required can be reduced and the necessary number of workers can be easily adjusted when the demand rates are changed. In this paper, we present a new genetic algorithm(GA) to minimize the number of workstations primarily and improve the work relatedness secondarily in the U-line production systems. Also, a new heuristic method is presented according to the work related factors and characteristics of U-line balancing. Some major aspects of the proposed GA are discussed, with emphasis on representation, decoding and evaluation function. Extensive experiments are carried out on well-known test-bed problems in the literature to verify the performance of our algorithm . The computational results show that our algorithm is a promising alternative to existing heuristics.

• East Asian mathematical journal
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• 제39권3호
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• pp.271-278
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• 2023

We consider a 1-dimensional reaction diffusion equation with the following boundary conditions arising in a theory of the thermal explosion {-u"(t) = λf(u(t)), t ∈ (0, l), -u'(0) + C(0)u(0) = 0, u'(l) + C(l)u(l) = 0, where C : [0, ∞) → (0, ∞) is a continuous and nondecreasing function, λ > 0 is a parameter and f : [0, ∞) → (0, ∞) is a continuous function. We establish the extension of Quadrature method introduced in [8]. Using this extension, we provide numerical results for models with a typical function of f and C in a thermal explosion theory, which verify the existence, uniqueness and multiplicity results proved in [6].

• 한국수산과학회지
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• 제51권2호
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• pp.127-134
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• 2018

Arteriosclerosis is the major cause of coronary artery and cerebrovascular disease, which are leading causes of death. Pro-inflammatory cytokines induce injury to vascular endothelial cells by increasing cell adhesion molecules, leading to vascular inflammation, a major risk factor for the development of arteriosclerosis. In the current study, we investigated the inhibitory effect of enzymatic hydrolysate from Japanese mud shrimp Upogebia major on the inflammation of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$)-stimulated human umbilical vein endothelial cells (HUVECs). We first evaluated the antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities of eight U. major enzymatic hydrolysates: alcalase, papain, ${\alpha}$-chymotrypsin (${\alpha}-Chy$), trypsin, pepsin, neutrase, protamex and flavourzyme. Of these, ${\alpha}-Chy$ exhibited potent antioxidant and ACE inhibitory activities. The ${\alpha}-Chy$ hydrolysate was fractionated by two ultrafiltration membranes of 3 and 10 kDa. The ${\alpha}-Chy$ hydrolysate of U. major and its molecular weight cut-off fractions resulted in a significant reduction in NO production and a decrease in cell adhesion molecules [vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and endothelial-selectin (E-selectin)] and pro-inflammatory cytokines [interleukin-6 (IL-6), interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1)] in $TNF-{\alpha}$-stimulated HUVECs. These results suggest that enzymatic hydrolysate from U. major can be used in the control and prevention of vascular inflammation and arteriosclerosis.