• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.185.2-185.2
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• 2003

The typical approach of virtual screening is to prepare a 3D database and dock each member to the receptor, and carry out a post-analysis to make a final selection of compounds to be tested. The biological test of these compounds leads to 'hit'. The size of the 3D database is rate-determining factor because the docking process is still time-consuming method. The number of compounds for biological testing is cost-determining factor because the materials used in the test are cost-consuming. The use of the representative subsets derived from the entire database help reduce runtime of docking procedure. (omitted)

• Membrane and Water Treatment
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• 제1권4호
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• pp.283-296
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• 2010

During the disinfection of potable water, humic substances present in the solution react with chlorine to form potential carcinogenic compounds. This study evaluates the feasibility of using a submerged membrane photocatalysis reactor (SMPR) process for treatment of humic substances through the characterization of both organic removal efficiency and membrane hydraulic performance. A simple SMPR was operated and led to the removal of up to 83% of the polluting humic matters. Temporal rates of organic removal and membrane fouling were found to decrease with filtration time. Using tighter membrane in the hybrid process resulted in not only higher organic removal, but also more significant membrane fouling. Under the experimental conditions tested, optimum $TiO_2$ concentration for humic removal was found to be 0.6 g/L, and increasing initial pollutant concentration expectedly resulted in a more substantial membrane fouling. The importance of the influent nature and pollutant characteristics in this type of treatment was also assessed as various water sources were tested (model humic acid solution vs. local water containing natural organic matters). Results from this study revealed the promising nature of the SMPR process as an alternative technique for organic removal in the existing water treatment system.

• 경영정보학연구
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• 제23권3호
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• pp.159-176
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• 2021

기존 연구들은 주로 사용자의 게임 참여 동기나 사회적 욕구에 따른 이탈 요인을 연구하였다. 하지만, 기존 연구들은 게임 참여 동기 관점에서 집중하다 보니, 사용자 불만 사항 개선에 따른 사용자 이탈에 관한 분석은 비교적 적게 이루어져왔다. 게임에 대한 사용자 불만 사항과 그에 따른 게임 품질 개선은 사용자가 게임에 참여하는 요인 중 하나이다. 따라서, 본 연구는 사용자 불만 요인이 사용자 이탈에 미치는 영향을 실증적으로 분석하여 그 관계를 살펴보고자 한다. 본 연구는 최근 유행했던 "PUBG - 배틀그라운드 게임"을 분석하여 제품 품질에 대한 불만 사항 피드백이 얼마나 사용자 이탈에 영향을 주는지 실증적으로 분석 한다. 텍스트 마이닝(Text Mining) 분석을 통해, 사용자들의 품질에 대한 불만요인을 도출하였고, 콕스모델(Cox Model)을 통해 불만 요인에 따른 사용자의 이탈률을 추정하였다. 또한 준실험설계 방법을 통해 실제 불만사항 개선 패치에 따라 사용자 수가 어떻게 변화하는지 살펴봄으로 본 연구 결과를 검증하였다. 분석 결과, 불만 사항 중 게임의 재미와 관련된 요인들이 사용자 이탈에 가장 큰 영향을 주었고, 반면 게임 사용 편의성과 관련된 불만 사항들은 비교적 사용자 이탈에 적은 영향을 준다는 것을 실증적으로 보였다. 본 연구결과에 따르면, 게임 불만 요인 개선에 따라 사용자들의 이탈 정도가 달라질 수 있으며, 이에 따라 게임 사용자 관리를 할 수 있다는 것을 밝혀냈다. 본 연구는 게임 개발 및 운영사 입장에서 사용자들의 불만 사항 개선에 대한 우선 순위를 제공해 줌으로서 실증적인 공헌을 제시한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.150-150
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• 2016

Mankind is enjoying a great convenience of their life by the rapid growth of secondary industry since the Industrial Revolution and it is possible due to the invention of huge power such as engine. The automobile which plays the important role of industrial development and human movement is powered by the Engine Module, and especially Diesel engine is widely used because of mechanical durability and energy efficiency. The main work mechanism of the Diesel engine is composed of inhalation of the organic material (coal, oil, etc.), combustion, explosion and exhaust Cycle process then the carbon compound emissions during the last exhaust process are essential which is known as the major causes of air pollution issues in recent years. In particular, COx, called carbon oxide compound which is composed of a very small size of the particles from several ten to hundred nano meter and they exist as a suspension in the atmosphere. These Diesel particles can be accumulated at the respiratory organs and cause many serious diseases. In order to compensate for the weak point of such a Diesel Engine, the DPF(Diesel Particulate Filter) post-cleaning equipment has been used and it mainly consists of ceramic materials(SiC, Cordierite etc) because of the necessity for the engine system durability on the exposure of high temperature, high pressure and chemical harsh environmental. Ceramic Material filter, but it remains a lot of problems yet, such as limitations of collecting very small particles below micro size, high cost due to difficulties of manufacturing process and low fuel consumption efficiency due to back pressure increase by the small pore structure. This study is to test the possibility of new structure by direct infiltration of SiC Whisker on Carbon felt as the next generation filter and this new filter is expected to improve the above various problems of the Ceramic DPF currently in use and reduction of the cost simultaneously. In this experiment, non-catalytic VS CVD (Vapor-Solid Chemical Vaporized Deposition) system was adopted to keep high mechanical properties of SiC and MTS (Methyl-Trichloro-Silane) gas used as source and H2 gas used as dilute gas. From this, the suitable whisker growth for high performance filter was observed depending on each deposition conditions change (input gas ratio, temperature, mass flow rate etc.).

• 생명과학회지
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• 제29권11호
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• pp.1179-1191
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• 2019

암세포는 epithelial mesenchymal transition (EMT)를 통해 tumor invasion과 metastasis가 일어나며, 또한 정상세포와 다른 oncogenic metabolic phenotypes 획득 즉, glycolytic switch 등이 암 발생과 진행에 깊이 연관되어 있음이 잘 알려져 있다. High-mobility group box 1 (HMGB1)은 chromatin-associated nuclear protein으로 알려져 있으나, dying cells 또는 immune cells로부터 방출되기도 한다. 방출된 HMGB1은 damage-associated molecular pattern (DAMP)로서 작용하여 EMT 및 invasion, metastasis를 유도함으로서 tumor progression에 기여한다고 알려졌다. 본 연구에서 HMGB1에 의해 EMT와 glycolytic switch 유도되며, 이 과정은 Snail 의존적임을 확인하였다. 또한 HMGB1/Snail cascade는 COX subunits인 COXVIIa와 COXVIIc의 발현 억제를 통해 mitochondrial repression과 cytochrome c oxidase (COX) inhibition을 유도하였다. HMGB1은 Snail를 통해 glycolytic switch의 주요 효소인 hexokinase 2 (HK2), phosphofructokinase-2/fructose-2,6-bisphosphatase 2 (PFKFB2), phosphoglycerate mutase 1 (PGAM1)의 발현을 증가시켰다. 이들 효소는 glycolytic switch에 중요하게 관여하는 것으로 알려져 있다. 이들 해당과정의 효소들을 knockdown한 결과 HMGB1에 의한 EMT를 억제함으로써 glycolysis와 HMGB1-induced EMT가 밀접하게 연관되어 있을 제시하였다. 이상의 연구 결과들은 HMGB1/Snail cascade가 EMT 및 glycolytic switch, mitochondrial repression에 중요하게 작용할 것임을 시사한다.

• 한국세라믹학회지
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• 제42권7호
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• pp.475-482
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• 2005

Zn$_{l-x}$Co$_{x}$O (x = 0.05 - 0.20) films were grown on Coming 7059 glass by sol-gel process. A homogeneous and stable Zn$_{l-x}$Co$_{x}$O sol was prepared by dissolving zinc acetate dihydrate (Zn(CH$_{3}$COO)$_{2}$$\cdot$2H$_{2}$O), cobalt acetate tetrahydrate ((CH$_{3}$)$_{2}$$\cdot$CHOH) and aluminium chloride hexahydrate (AlCl$_{3}$ $\cdot$ 6H$_{2}$O) as solute in solution of isopropanol ((CH$_{3}$)$_{2}$$\cdot$CHOH) and monoethanolamine (MEA:H$_{2}$NCH$_{2}$CH$_{2}$OH). The films grown by spin coating method were postheated in air at 650°C for 1 h and annealed in the condition of vacuum (5 $\times$ 10$^{-6}$ Torr) at 300$^{\circ}C$ for 30 min and investigated the nature of c-axis preferred orientation and physical properties with different Co concentrations. Znl_xCOxO thin films with different Co concentrations were well oriented along the c-axis, but especially a highly c-axis oriented Zn$_{l-x}$Co$_{x}$O thin film was grown at 10 at$\%$ Co concentration. The transmittance spectra showed that Zn$_{l-x}$Co$_{x}$O thin films occur typical d-d transitions and sp-d exchange interaction became activated with increasing Co concentration. The electrical resistivity of the films at 10 at$\%$ Co had the lowest value due to the highest c-axis orientation. X-ray photoelectron spectroscopy and alternating gradient magnetometer analyses indicated that no Co metal cluster was formed, and the ferromagnetic properties appeared, respectively. The characteristics of the electrical resistivity and room temperature ferromagnetism of Zn$_{l-x}$Co$_{x}$O thin films suggested the possibility for the application to dilute magnetic semiconductors.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.70-70
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• 2003

The uterus undergoes dynamic changes during the cycle and displays many features typical of developmental process. In order to be prepared for implantation, endometrium undergoes predictable, sequential phases of proliferation and secretory changes. The uterus during estrus cycle synthesize a complex of signaling molecules with specific spatial and temporal modes of expression and which are critical for cell proliferation and differentiation. The purpose of this investigation was to use cDNA microarrays to evaluate the expression of genes of rat uterus in estrus cycle. Animals were sacrificed on proestrus, estrus, metestrus, diestrus. Differential gene expression profiles were revealed(growth-related c-myc reponsive protein RCL, heat shock 47-kDa protein (HSP47), cytochrome c oxidase polypeptide Vlc2 (COX6C2), calreticulin (CALR)). Reverse transcription polymerase chain reaction (RT-PCR) was used to validate the relative expression pattern. Using this approach, we found several genes whose expression in rat uterus was altered with estrus cycle. Our long-term goal is to determine the role of these differentially expressed genes during estrus cycle. This study was supported by through the Biohealth Products Research Center(BPRC), Inje University.

• Journal of Plant Biotechnology
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• 제42권4호
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• pp.364-369
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• 2015

Safflower (Carthamus tinctorius) seeds are wellknown traditional oriental medicines that have long been used for the remedies of blood stasis and bone formation in east Asia. In this study, ethyl acetate (EtOAc) was used for extraction of the main chemical compounds from C. tinctorius seeds. Four major compounds were identified, acacetin, cosmosiin, N-feruloyl serotonin and N-(p-coumaroyl) serotonin. Each compound was evaluated for its inhibitory activity against the inflammatory process of macrophages. All compounds significantly inhibited production of lipopolysaccharide (LPS)-stimulated nitric oxide (NO) and pro-inflammatory cytokines. The protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were dramatically decreased by serotonins in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophages. These results suggest that serotonin derivatives from safflower seeds may reduce inflammation-related diseases.

• 대한수학회지
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• 제57권5호
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• pp.1167-1186
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• 2020

This paper considers the case of pricing discretely-sampled variance swaps under the class of equity-interest rate hybridization. Our modeling framework consists of the equity which follows the dynamics of the Heston stochastic volatility model, and the stochastic interest rate is driven by the Cox-Ingersoll-Ross (CIR) process with full correlation structure imposed among the state variables. This full correlation structure possesses the limitation to have fully analytical pricing formula for hybrid models of variance swaps, due to the non-affinity property embedded in the model itself. We address this issue by obtaining an efficient semi-closed form pricing formula of variance swaps for an approximation of the hybrid model via the derivation of characteristic functions. Subsequently, we implement numerical experiments to evaluate the accuracy of our pricing formula. Our findings confirm that the impact of the correlation between the underlying and the interest rate is significant for pricing discretely-sampled variance swaps.

• 천문학회보
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• 제44권2호
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• pp.78.2-78.2
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• 2019

The temperature control of a scientific device is essential because extreme temperature conditions can cause hazard issues for the operation. We developed a software which can interact with the temperature sensor using the GMT SDK(Giant Magellan Telescope Software Development Kit) version 1.6.0. The temperature sensor interacts with the EtherCAT(Ethernet for Control Automation Technology) slave via the hardware adapter, sending and receiving data by a packet. The PDO(Process Data Object) and SDO(Service Data Object), which are the packet interacts with each EtherCAT slave, are defined on the TwinCAT program that enables the real-time control of the devices. The user can receive data from the device via grs(GMT Runtime System) tools and log service. Besides, we programmed the software to print an alert message on the log when the temperature condition changes to certain conditions.