• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.1
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• pp.46-51
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• 2004

Talon cusp is cusp-like structure that develops additionally in crown of anterior tooth. And it is one of dental anomalies. Talon cusp can cause various diagnostic, functional, aesthetic problems depending on the size and configuration of cusp. there is a tendency for caries to occur in the developmental grooves, and advanced attrition, periodontal problems, irritation the tongue and temporomandibular pain, occlusal interference and displacement of affected tooth may result. Therefore, early diagnosis and appropriate treatment of each case is important so that it minimize local problems, such as caries, periodontal diseases, and malocclusion. These cases which are in permanent and primary anterior teeth are about gradual reduction forming reparative dentine and complete reduction of talon cusp and root canal therapy which is an alternative and effective form of treatment when gradual reduction of talon cusp may not be possible.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.32-41
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• 2009

In this study, scale-down design of full-scale Korean Utility Helicopter (KUH) main rotor blade has been investigated. The scaled model system were designed for the measurement of aerodynamic performance, tip vortex and noise source. For the purpose of considering the same aerodynamic loads, the Mach-scale method has been applied. The Mach-scaled model has the same tip Mach number, and it also has the same normalized frequencies. That is, the Mach-scaled model is analogous to full-scale model in the view point of aerodynamics and structural dynamics. Aerodynamic scale-down process could be completed just by adjusting scaling dimensions and increasing rotating speed. In the field of structural dynamics, design process could be finished by confirming the rotating frequencies of the designed blade with the stiffness and inertial properties distributions produced by sectional design. In this study, small-scaled blade sectional design were performed by applying domestic composite prepregs and structural dynamic characteristics of designed model has been investigated.

• Journal of KIISE:Software and Applications
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• v.36 no.1
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• pp.10-20
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• 2009

As unit testing should be performed repeatedly and continuously, it is a high-cost software development activity. Although there are many studies on unit test automation, there are less studies on automated test case generation which are worthy of note. In this paper, we discuss a study on automated test data generation from source codes and indicate algorithms for each stage. We also show some issues of test data generation and introduce an automated test data generating tool: CUTIG. As CUTIG generates test data not from require specifications but from source codes, software developers could generate test data when specifications are insufficient or discord with real implementation. Moreover we hope that the tool could help software developers to reduce cost for test data preparation.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.173-184
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• 2008

Climatic water balance has been applied to obtain quantity of various hydrologic components. Hydrologic information is estimated by comparison between rainfall and evapotranspiration under complex terrain condition. Water deficit is defined as that subtraction of actual supply from climatic demand. The water deficit will occur, when monthly evapotranspiration exceed monthly rainfall. Contrary water surplus is defined as that surplus water after meeting the demand by plants. The water surplus will be occurred when monthly rainfall exceeds monthly evapotranspiration. Finally, the discrete moisture indices were calculated and mapped for the whole watershed to estimate dryness and wetness status using the climatic water balance approach. The result of this study can properly interpret the real drought and non drought. Based upon the results, it can be concluded that the climatic water balance model is useful to monitor water conditions for the watershed.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1039-1042
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• 2008

In order to increase a functionality, OH value, for a recycled polyol prepared from the glycolysis reaction of a waste polyurethane rigid foam(PUR), the effect of an addition of pentaerythritol(PEN, functionality(f)=4) or sorbitol(SOR, f=6) to the its glycolysis reactor on the prepared polyol functionality and the mechanical properties of the polyurethane prepared using it was investigated. The OH values increased from 2.2 for a virgin to 2.8 for the recycled polyol. There was an increase in the mechanical properties including dimensional stability for PUR prepared using the recycled polyol, in which the increased OHs provided higher crosslinking density during PUR synthesis. In addition, the amount of the recycled polyol in the polyol system increased to from 8 to 20 wt% to give better mechanical properties to the PUR.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.1
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• pp.1-13
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• 1992

The objective of this study is to develop knowledge-based system for the preliminary design and midship section design of bulk carrier and to enhance the applicability of knowledge engineering in the field of Naval Architecture. First, expert system shell called E.1 is developed in C language. E.1 supports backward-chaining, automatic iteration procedure and reiterative inference mechanism for efficient application of knowledge-based system in structural design. Knowledge representation in E.1 includes IF-THEN rules, 'facts'and 'tables'. Second, knowledge bases for the principal particulars and midship section design are developed by experimental formula, design standard and experiential knowlege. Third, hybrid system combined this knowledge-based system with the optimization program of midship section is developed. Finally, the simplified design method utilizing the regression analysis of the optimum results of stiffened plate is developed for facilitating the design process. Using this knowledge-based system, the design process and results for Bulk carrier and stiffened plates are discussed. It is concluded that knowledge-based system is efficient for preliminary design and midship section design of the ship. It is expected that the performance of the CAD system would be enhanced if the better knowledge-base is accumulated in the E.1 tool.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.138-146
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• 2020

The paper deals with comparative study of characteristics of surrogate models and sensitivity evaluation using design of experiments in order to enhance and analysis the structure design of an automatic salt collector under various design load conditions. Orthogonal array design based on numerical analysis was used for the design of experiments. The thickness sizing variables of main structure member were considered the design factors, and the output responses were selected from the strength performances as well as the weight. The quantitative effects on responses for each design factor were evaluated from the orthogonal array experiment. Optimum design case was also identified to improve the strength performances with weight minimization. Using the orthogonal array experiment. various surrogate models such as response surface model, Kriging model, and Chebyshev orthogonal polynomial were generated. The orthogonal array experiment results were validated by the surrogate modeling results. The most suitable surrogate model was the response surface model for the exploration of design space of the automatic salt collector.

• Fire Science and Engineering
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• v.28 no.5
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• pp.37-43
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• 2014

In the case of interior fire in an apartment building, contamination of vestibule area by fire smoke before air fan operating when fire doors are open makes the evacuation of people very difficult. In order to investigate the effect of heat release rate (HRR) and interior opening on fire flow velocity, numerical simulations using Fire Dynamics Simulator were carried out. In simulations, actual dimensions and configuration of an apartment building were considered and interior leakage and HRR were varied. From simulation results, it was found that fire flow velocity distribution is significantly influenced by HRR and interior opening resulting in the change of the location of a neutral plane. Also, it is shown that there is a larger difference of the fire flow velocity between upper and lower part of the fire door when the neutral plane becomes closer to the ceiling.

• Korean Journal of Pharmacognosy
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• v.48 no.2
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• pp.108-112
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• 2017

To isolate and identify the constituents of the fruit galls of Actinidium polygama as well as evaluate the anti-inflammatory effects of the isolated compounds, a total of five triterpenes were isolated including $2{\alpha},3{\alpha},24$-trihydroxy-12-ursene-23-al-28-oic acid (1), corosolic acid (2), $2{\alpha},3{\alpha},24$-trihydroxyurs-12,20(30)-dien-28-oic acid (3), $2{\alpha},3{\alpha},24$-trihydroxyolean-12-en-28-oic acid (4), and $2{\alpha},3{\alpha},24$-trihydroxyurs-12-en-28-oic acid (pygenic acid B) (5). Compounds 1, 3, and 4 were isolated from the fruit galls of A. polygama for the first time. Compound 3 decreased NO production in LPS-stimulated RAW264.7 macrophages and mouse microglia BV2 cells in a concentration-dependent manner.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.970-970
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• 2012

최근 치수의 기능을 수행하면서 원래 자연하천의 모습을 보전 혹은 복원하는 "생태하천 복원 공법"의 필요성이 대두되고 있으나 구체적인 공법에 대한 연구는 미미한 실정이다. 본 연구에서는 하천 내 시설물의 조성 시 유황에 따른 자연 하안 유도와 습지형태의 생물 서식공간 조성 유무를 평가하기 위하여 평창강 일원에 목재 유도틀을 설치하고 이에 따른 지형변화, 저서무척추동물을 포함한 수생생물들의 서식특성을 분석하였다. 평창강 금당계곡 일원을 대상으로 RMA-2 모형의 범용프로그램인 SMS 모형을 통해 수리 특성분석을 실시하였고 안산에 있는 수리모형 실험장에서 기본 수리특성 실험 후 수리적 안정성이 확보된 지점에 목재 유도틀을 2009년 9월에 설치하여 유도틀 설치 전과 설치 후 2010년 10월까지의 지형변화를 분석하였다. 지형의 측량은 광파측정기(니콘 DTM-520)로 하였으며 측량된 자료를 이용하여 Contour Map을 작성하여 지형변화를 분석하였고, 유도틀 설치지역을 중심으로 2010년에 3차에 걸쳐 지형 및 생물상 변화에 대한 정량 및 정성조사를 실시하여 비교분석 하였다. 유도틀 설치 후 2010년 하절기에 집중호우에 의한 유도틀의 파손 및 형태변형 등 문제가 없어 수리적으로 안정한 것으로 판단되었다. 지형 변화의 측면에서는 유도틀 조성 전 사질로 되어있던 단순한 선형의 하안이 유도틀 설치 후 다양한 하상재질 및 형태가 변화했으며 유도틀의 배치에 따라서 굼치 및 둠벙형 습지가 형성되었다. 유도틀 설치지역의 3개지점(상부, 중간배후습지, 하부)에서 저서무척추동물에 대하여 모니터링한 결과, 설치된 유도틀의 중간지점에서 가장 높게 종의 서식이 확인되었으며 상부지점과 하부지점은 상대적으로 낮게 나왔으나 상부지점 보다는 하부지점이 양호하게 나타났다. 조사시기별 개체수의 변화에서는 종수변화와 패턴이 유사하게 나타났으며 깔다구와 꼬마줄날도래등 특정종의 증식이 많았다. 또한, 굼치 및 둠벙형 습지 내에 어류의 치어 및 유어, 양서류, 파충류등 다양한 생물의 서식이 확인되었다. 이는 유도틀에 의해 생성 및 유도된 지형변화가 하천을 기반으로 생활하는 생물들에게 다양한 피난처 및 은신처 역할을 잘 제공하고 있음을 보여준다.