• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.5 s.236
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• pp.647-654
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• 2005

This research Proposes a Process design of injection molded microcellular plastic gears for enhancing the fatigue strength/durability and accuracy of the gears applying thermodynamic instability to microcellular foaming process. To develop the injection molded plastic gears by way of microceliular process, it is absolutely necessary the following two process design. The first is microcellular forming process for enhancing the strength/durability of plastic gears. To be microcellular process succeeded, based on the microcellular principle, mechanical apparatus is designed where nucleation and cell growth are to be generated renewably. The second is the counter pressure process which is mainly fur improving the tooth surface roughness and the accuracy of microcellular gears. For the former process, screw, nozzle and gas equipment are newly designed, and for the latter, counter pressure by nitrogen gas is intentionally brought about into mold cavity when injecting plastic gears. Based on the proposed process design, using gear mold, experiments of injection molding show that, in internal space of plastic gears, microcellular nuclear cells less than 5 lim in diameter have been generated homogeneously via electron microscope photos.

• The Korean Journal of Zoology
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• v.23 no.1
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• pp.13-24
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• 1980

The germarium contains the apical complex consisting of a multinucleated syncytium. Apical complex has a nutritive role for the early spermatogonia. Trophocytes are irregularly shaped and are distributed throughout the space from spermatogonial cysts to sperm bundles, and they increase in size by endopolyploidization. As meiotic divisions are not complete until the final moult, spermatogenesis continues even in the adult. Chromosome number is 2n=24. Spermiogenesis is divided into seven stages in terms of chromatin concentration, cytoplasmic granules, and the nuclear size and shape. These stages could be grouped into the spherical, the elongating and the rodform spermatids in shape.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.254-258
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• 2006

Decrease of children caused by economic growth, scientific and technological advancement, long life, spread of nuclear families, increase of women's entry in public affairs, etc. in modern society has given rise to aging societies as another social problem. This has resulted in the advent of problems of the aged and necessity of geriatric hospitals specializing in providing medical services for the old. Even though the geriatric hospitals currently operated are mainly used by aged persons, however, their color environment has been decided, for the most pin, not in view of characteristics of the old but in view of supporting families' criteria for selection of facilities. This study intends to help geriatric hospital designers recognize importance of color environment considering characteristics of the old and select the relevant colors In designing geriatric hospitals in future to elevate remedial value and prevent accidents in space use. To this end, this study suggests problems of color environment found in surveys of the existing geriatric hospitals currently operated throughout the nation and further make some proposals for improvement.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.35-38
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• 2000

Conventional atom model must be criticized on the following four points.(1) natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc.(2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The hv is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not changed during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body.New atomic model 9the crystallizing $\pi$-bonding) was proposed in the journal of material processing technology since 1997 for the explanation of the mechanical behaviors in terms of physics. $\prod$-ray physics proved that the electrons can come out from in the nucleus and modern chemistry corresponds to the $\pi$-bonding by the nuclear electrons. The $\pi$-bonding structure of the protons outside the nucleus is that electrons move between protons of the different atoms. The perception step and the characteristic frequency in signal transduction is due to the accumulation of the $\pi$-rays outside of the proton before their absorption to the nucleus.

• Tunnel and Underground Space
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• v.9 no.2
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• pp.102-113
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• 1999

Two-dimensional and three-dimensional DEM programs, UDEC and 3DEC, were used to investigate the mechanical stability of the conceptual design of deposition drift and deposition holes constructed in a crystalline rock mass. From the simulations, the influence of discontinuities, the number of deposition holes, and deposition hole interval on the stability of deposition drift and deposition holes could be determined. From the two-dimensional and three-dimensional analysis. it was concluded that three-dimensional analysis should be carried 7ut fur deriving reliable conclusions. Even though the deposition hole interval changed from 8 m to 3 m, which did not damage the mechanical stability of the deposition drift.

• Genomics & Informatics
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• v.9 no.3
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• pp.93-101
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• 2011

The Hairless (HR ) gene regulates the expression of several target genes as a transcriptional corepressor of nuclear receptors. The hair follicle (HF), a small independent organ of the skin, resides in the epidermis and undergoes regenerative cycling for normal hair formation. HF development requires many genes and signaling pathways to function properly in time and space, one of them being the HR gene. Various mutations of the HR gene have been reported to cause the hair loss pheno-type in rodents and humans. In recent studies, it has been suggested that the HR gene is a critical player in the regulation of the hair cycle and, thus, HF development. Furthermore, the HR gene is associated with the Wnt signaling pathway, which regulates proliferation and differentiation of cells and plays an essential role in hair and skin development. In this review, we summarize the mutations responsible for human hair disorders and discuss the roles of the HR gene in HF development.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.137-142
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• 2009

The purpose of this study is to collect baseline data about the demands for housing regeneration of the permanent rental apartment dwellers. Self-administered questionaires and interviews were provided to 144 dwellers in Incheon Man-soo 7 complex from 2008 December 29th to 31st. The collected data was used to conduct comparative and descriptive statistical analysis: frequency, t-test, and $X^2$-test. The main findings are as follows : 1. House repairing and papering is most common used service by respondents. They also have much need for economic support. 2. Residents were satisfied with general environment of house. This survey showes that the highest satisfaction was about using food waste disposal sites. and the lowest satisfaction was about soundproof facilities on the other hand, among the questions. 3. Dwellers wanted to remodeling such as bathroom, restroom, a flower garden, space of landscape architecture. More than half dwellers preferred to leave among themselves living at permanent rental apartment as it is. 4. There is important difference in the demands of housing regeneration as the family trait. and variables of those were nuclear family or elderly/handicapped-family.

• Journal of the Korean housing association
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• v.21 no.1
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• pp.43-51
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• 2010

The purpose of this study is to collect baseline data about the demands for housing regeneration of the permanent rental apartment dwellers. Self-administered questionnaires and interviews were provided to 144 dwellers in Incheon Man-soo 7 complex from 2008 December 29th to 31 st. The collected data was used to conduct comparative and descriptive statistical analysis: frequency, t-test, and $\chi^2$-test. The main findings are as follows: 1. House repairing and papering is most common used service by respondents. They also have much need for economic support. 2. Residents were satisfied with general environment of house. This survey shows that the highest satisfaction was about using food waste disposal sites, and the lowest satisfaction was about soundproof facilities on the other hand, among the questions. 3. Dwellers wanted to remodeling such as bathroom, restroom, a flower garden, space of landscape architecture. More than half dwellers preferred to leave among themselves living at permanent rental apartment as it is. 4. There is important difference in the demands of housing regeneration as the family trait, and variables of those were nuclear family or elderly, handicapped-family.

• Progress in Superconductivity and Cryogenics
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• v.17 no.2
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• pp.31-35
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• 2015

Mapping is a useful tool in the magnetic field analysis and design. In some specific research area, such as the nuclear magnetic resonance (NMR) or the magnetic resonance imaging (MRI), it is important to map the magnetic field in the interesting space with high accuracy. In this paper, an indirect mapping method in the center volume of an air-core solenoid is presented, based on the solution of the Laplace's equation for the field. Through the mathematical analysis on the mapping calculation, we know that the condition number of the matrix, generated by the measurement points, can greatly affect the error of mapping result. Two different arrangement methods of the measurement points in field mapping are described in this paper: helical cylindrical line (HCL) method and parallel cylindrical line (PCL) method. According to the condition number, the HCL method is recommended to measure the field components using one probe. As a simple example, we mapped the magnetic fields in a MRI main magnet system. Comparing the results in the different methods, it is feasible and convenient to apply the condition number to reduce the error in the field mapping calculation. Finally, some guidelines were presented for the magnetic field mapping in the center volume of the air-core solenoid.

• The Journal of Internal Korean Medicine
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• v.25 no.3
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• pp.508-517
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• 2004

This study was performed to investigate the effectiveness of Hangryunhaedocktang (HHT) on epidermal damages induced by allergic contact dermatitis (ACD). The sensitization were caused by one application of $25{\mu}l$ of 5% 2,4-dinitroch1orobenzene (DNCB) onto a back-lumbar skin of BALB/c mice. 2 weeks later, ACD was elicitated with $4{\mu}l$ of 2.5% DNCB and then mice were given HHT extract in doses of 3.3ml/kg/day, for 72 hours. The ACD induced epidermal damages in HHT treated ACD mice was more mitigated than non-treated ACD elicited mice. The features related with epidermal damage such as epidermal hyperplasia, infiltration of inflammatory cells, increase of nuclear shrinkages and vacuolation, and enlargement of intercellular space softened. And the distribution of soybean agglutinin (SBA) positive reaction in stratum spinosum (SS) and stratum basale (SB) were similarly maintained in a normal configuration. The numerical decrease of BrdU, TUNEL, and Fas positive cells observed were prominent in SB. Results suggest a benefit role for HHT in mitigating epidermal damages in mice with allergic contact dermatitis.