• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 춘계학술대회 논문집
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• pp.71-79
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• 1994

Strip drawing of strain-hardening, viscoplastic materials with damage is analyzed by a rigid plastic finite element method. A process model is formulated using two state variables, one for strain hardening from slip dominated plastic distortion and the other for damage from growth of microvoids. Application of the model to steady state drawing is given via implementation in a consistent penalty finite element formulation. The predicted density changes as a result of void growth are compared to those from experiments reported in the literature. The effects of drawing conditions such as drawing speed and die angle on the mechanical property changes are studied.

• Structural Engineering and Mechanics
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• 제34권3호
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• pp.285-300
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• 2010

The two-dimensional deformation of a homogeneous, isotropic thermoelastic half-space with voids with variable modulus of elasticity and thermal conductivity subjected to thermomechanical boundary conditions has been investigated. The formulation is applied to the coupled theory(CT) as well as generalized theories: Lord and Shulman theory with one relaxation time(LS), Green and Lindsay theory with two relaxation times(GL) Chandrasekharaiah and Tzou theory with dual phase lag(C-T) of thermoelasticity. The Laplace and Fourier transforms techniques are used to solve the problem. As an application, concentrated/uniformly distributed mechanical or thermal sources have been considered to illustrate the utility of the approach. The integral transforms have been inverted by using a numerical inversion technique to obtain the components of displacement, stress, changes in volume fraction field and temperature distribution in the physical domain. The effect of dependence of modulus of elasticity on the components of stress, changes in volume fraction field and temperature distribution are illustrated graphically for a specific model. Different special cases are also deduced.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1995년도 제27회 학술발표회
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• pp.58-82
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• 1995

This study providesd an empirical analysis of trip-chaining behavior and its application to transportation planning. In the empirical analysis, changes in trip-chaining patterns since 1970 have been examined and details of current trip-chaining behavior as they describe shopping trip-chaining behavior has changed. Individual trip-chaining has become longer and complex. It appears that the average number of trips per chains has substantially increased over the past 20 years. An increased number of trips in chains means fewer home-based trips. Changes in trip-chaining behavior have several consequences. Important consequences are for transportation and land-use planning. Up to now trips have been treated as if they are independent clusters of home-to-destination-to-home; this approach has not usually taken into account the trip-chaining behavior of individuals. this calls for a different approach to at least the trip generation and trip distribution part of transportation planning. In this study, application of trip-chaining behavior to trip distribution model formulation is proposed and its calibration results are presented.

• Industrial Engineering and Management Systems
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• 제7권1호
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• pp.23-33
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• 2008

This paper proposes an approach to monitoring and scheduling methods for repetitive MIMO-FIFO DESs. We use max-plus algebra for modeling and formulation, known as an effective approach for controller design for this type of system. Because a certain type of linear equations in max-plus algebra can represent the system's behavior, the principal concerns in past researches were how to solve the equations. However, the researches focused mainly on analyses of the relation between inputs and outputs of the system, which implies that the changes or the slacks of internal states were not clarified well. We first examine several properties of the corresponding state variables, which contribute to finding and tracing the float times in each process. Moreover, we provide a rescheduling method that can take into account delays or changes of the internal states. These methods would be useful in schedule control or progress management.

• 셀메드
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• 제11권4호
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• pp.18.1-18.8
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• 2021

Jawarishe Jalinoos (JJ) is an orally used formulation available in semisolid dosage form, prepared with powdered plant materials mixed in honey or sugar syrup. It has many admirable pharmacological effects and used in Unani medicine to treat various acute and chronic disorders since ancient times. The ICH Harmonised Tripartite Guideline stated that photostability testing should be an essential part of stability testing to confirm that light exposure does not result in an unacceptable change in drugs substance and finished products. To date, the effect of light on JJ is not studied, in this study photostability evaluation of JJ was carried out. The test sample was manufactured with genuine ingredients in the in-door pharmacy of the National Institute of Unani Medicine. JJ was packed in two transparent polyethylene terephthalate airtight containers. The first sample was analysed at zero-day and the second sample was placed in a stability chamber subjected to light challenge with an overall illumination of 1.2 million lux hours combined with near ultraviolet energy of 200-watt hours per square meter by using option 2, along with 30±2℃ temperature and relative humidity 70±5%. Analysis of both finished products showed no considerable changes in organoleptic characters. Less than 5% variation was observed in physicochemical parameters. HPTLC fingerprinting showed justifiable variation. Microbial load and specific counts were within the limit prescribed by WHO. As no unacceptable changes were noted in JJ subjecting to light challenge, it is concluded that JJ is a photostable Unani compound formulation.

• 기술혁신학회지
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• 제16권3호
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• pp.839-860
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• 2013

본 연구는 대표적인 지식기반산업인 생명의료산업의 첨단의료복합단지 조성정책을 대상으로 하여 정책형성과정을 분석하고자 한다. 첨단의료복합단지는 다양한 분석요소와 속성들을 내포하고 있기 때문에 국내외 정치적 경제적 사회적 환경변화에 따른 정책형성과정을 Kingdon(1984, 1995, 2003)의 '정책흐름모형'을 적용하여 분석하였다. 2005년 8월 의료산업선진화위원회가 출범한 시기에서 2008년 3월 '첨단의료복합단지특별법'이 제정되기까지 정책형성 과정을 대상으로 하였다. 분석결과 첨단 의료산업분야의 정책형성 과정은 여러 요인들과 정책흐름들이 간여되어 있으며, 특히 정책의제가 정부의제로 공식화되는 법제화의 과정은 정책선도자 뿐만 아니라 다양한 이해관계자의 역동적인 역할에 의하여 진행된다는 점을 조명하였다.

• Journal of Pharmaceutical Investigation
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• 제38권3호
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• pp.157-162
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• 2008

The aim of the study was to formulate the stable amlodipine maleate tablet by selecting and combining of suitable ingredients. Amlodipine tablets were designed by using different manufacturing methods or formulations. Dissolution rate at 30 min of newly formulated tablets was over 98% in 0.1 M HCl medium. After 4 months storage under accelerated condition, the changes of appearance, loss on drying, content and total impurity were investigated. For long-term stability tests, two formulations of K017 (direct compressed tablets consisting of microcrystalline cellulose and pregelatinized starch) and K018 (wet granulated tablets by OpadryAMB) were stored under $25^{\circ}C$, 60% RH for 24 months. Under the accelerated condition, moisture content in K017 formulation was increased as 5.96% for 4 months, while other formulations with anhydrous monobasic phosphoric potassium or by wet granulation showed higher increase in moisture content compared to K017. In addition, K017 formulation showed a low decrease in contents and total relative substance as 0.8% and 0.7%, respectively. Similar stability of amlodipine in K017 was obtained under the long-term stability test. These results indicate that the K017 combined with microcrystalline cellulose and pregelatinized starch as ingredients is very stable formulation to protect active substance from moisture contact and sustain stability. Therefore, suitable combination of ingredients such as microcrystalline cellulose and pregelatinized starch could attribute to enhance the stability of moisture-labile drug such as amlodipine maleate.

• 한국산림과학회지
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• 제89권3호
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• pp.335-341
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• 2000

이 연구에서는 탄소저장 및 목재생산효과를 동시에 고려하여 최적 산림경영계획을 수립하기 위한 다목적 선형계획수식모형을 개발하고, 사례연구를 통해 탄소저장과 목재생산효과의 선호도에 따른 최적 산림수확계획의 변화 경향을 분석하였다. 연구대상지로는 홍천의 가리산 지역을 선정하였으며, 선형계획수식모형에는 비감소수확, 수확벌채량 및 수확면적의 최대, 최소범위, 계획기간말의 임상구조 등을 제약하는 다수의 조건들을 포함시켰다. 또한 탄소저장 및 목재생산효과와 같이 상충적인 요소를 경영계획에 반영하기 위한 합리적 절충방안의 하나로 경영목적의 선호도에 따른 결합생산가능곡선을 제시하였다.

• 공업화학
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• 제30권4호
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• pp.415-420
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• 2019

비이온 계면활성제와 유화안정제가 O/W 유화 제형에 미치는 영향을 살펴보기 위하여 비이온 계면활성제와 유화안정제 종류를 달리한 여러 제형을 만들어 이들의 유변학적 특성을 비교하였다. 친수성 비이온 계면활성제는 polysorbate 60 (Tween 60), PEG-60 hydrogenated castor oil (HCO 60), octyldodeceth-16 (OD 16), ceteareth-6 olivate (Olivem 800) 등을 사용하였고, 유화안정제로는 cetyl alcohol, glyceryl monostearate, stearic acid 등을 각각 사용하였다. Octyldodeceth-16을 사용한 유화 제형에서만 상분리가 일어나고 나머지 제형은 모두 안정한 상을 유지하였다. 계면활성제 ceteareth-6 olivate와 유화안정제 cetyl alcohol을 혼합 사용한 제형의 점도, 경도, 크림성 등이 가장 높게 나타나고 유화된 입자 사이즈도 가장 큰 값으로 측정되었다. 이와 같은 결과는 유화 제형에 액정이 많이 생성되면서 네트워크 구조의 텍스처가 형성되었기 때문이다. 이 제형에서는 탄성적 특성이 크게 나타나고 힘이 가해지는 이력에 따라 점도 값이 달라지는 씩소트로픽 현상이 나타났다.

• 공업화학
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• 제34권5호
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• pp.501-506
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• 2023

수크로스 에스터와 세라마이드를 혼합하여 겔레이터로 사용한 해바라기 오일의 올레오겔과 올레오겔 에멀전을 제조하였다. 올레오겔과 올레오겔 에멀젼 제형 내에서 겔레이터의 결정 구조는 편광현미경으로 관찰하고 물의 분산형태는 공초점 현미경으로 확인하였다. DSC 열차트 분석을 통해, 수크로스 에스터와 세라마이드를 혼합하면 세라마이드의 결정구조는 사라지고 제형에 물이 첨가되면 혼합된 겔레이터의 결정성이 더욱 상승함을 확인하였다. 제형에서의 수크로스 에스터, 세라마이드, 물의 비율에 따른 점도와 점탄성 등의 유변학적 특성의 변화를 살펴보았다. 세라마이드와 물의 함량이 증가할수록 점도 및 저장탄성률, 손실 탄성률 등이 모두 증가하고, 또한 제형의 안정성도 높아지는 경향을 보였다.