• 한국정밀공학회지
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• 제18권9호
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• pp.192-203
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• 2001

The design of gate and runner(delivery system) is one of the most important subject in injection molding. Delivery system is a channel to flow the polymer melt from the injection molding machine to the mold cavities. Also, delivery system affect quality and productivity of the part. The synthesis of delivery system of injection molding has been done empirically, since it requires profound knowledge about the moldability and causal effects on the properties of the part, which are not available to designers through the current CAD systems. GATEWAY is a knowledge module which contains knowledge to permit non-experts as well as mold design experts to generate the acceptable geometries of gate and runner far injection molded parts. A knowledge-based CAD system is constructed by adding the knowledge module, GATEWAY, to an existing geometric modeler. A knowledge-based CAD system is a new tool which enables the concurrent design and CIM with integrated and balanced design decisions at the initial design of injection molding.

• 한국정보시스템학회지:정보시스템연구
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• 제21권2호
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• pp.161-180
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• 2012

One of them is online community which is popular among this modern society. However, it is not appropriate to suggest that online community is solely for personal usage or solely for work-related usage. The usage of online community goes beyond only one purpose. On the other hand, our daily activities whether personal or work-related activities are usually accompanied with preconception ideas whether it is a fun activity or not. However, even with this preconception, individuals are still enjoying themselves while doing activities that are considered as boring or mundane. Furthermore, individuals are really into the activities that they forgot about their surrounding and found themselves being in flow while conducting these activities. Unfortunately, there is little research done in South Korea addressing this emotion related factors. Because of that, more research concerning emotion related factors need to be conducted to better understand users behavior especially in online environment. With regards to that concern, this research studied two distinct everyday activities which are studying and playing games in online community. It is expected that when an individual feels more enjoyable and feels more comfortable, it will be more likely for them to be more satisfied. This satisfaction will lead them to being in a flow state. Hence, this study proposed three hypotheses. In order to investigate these three hypotheses, studies were conducted in two stages. The first stage was conducted in order to derive the implicit knowledge about fun from the participants. The second stage was done by an empirical study. It was conducted with two sample groups. The first group is the study group and the second group is the play games group. There were asked a set of questionnaires related to their enjoyment, comfort, satisfaction and flow while conducting the relevant activity. The results showed that both groups reached the state of flow regardless whether they belong to the study group or play games group. Therefore, the preconception idea about an activity does not promote or prevent individuals from feeling enjoyment, feeling comfortable and achieve satisfaction while conducting those activities.

• 대한화학회지
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• 제46권3호
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• pp.279-286
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• 2002

이 연구의 목적은 대학생들이 유기화학 반응을 전자의 흐름으로 이해하는데 필요한 기초 지식에 대하여 어떤 선개념을 가지고 있으며, 기초적인 화학 반응을 전자의 흐름으로 이해하는 능력은 어느 정도인지 조사하여 교수 학습 방법에 도움을 주고자 하는데 있다. ?見?위해 H 대학교 화학교육과 2학년 18명을 연구 대상으로 선정하였고, 선행연구에서 밝혀진 연구결과를 근거로 하여 예비검사를 거쳐 검사도구를 개발하였다. 개발된 검사도구로 지필검사를 실시하여 대학생들의 응답을 통계처리 하였고, 통계적인 의미를 정성적으로 확인하기 위하여 면담을 실시하였다. 연구 결과, 대학생들의 원자의 전자배치에 대한 개념과 전자의 흐름에 기초하여 화학 반응을 이해하는데 필요한 기본 개념들에 대한 이해도는 높았으나, 이 개념들을 기초적인 화학 반응에 적용시키지는 못하였다. 그러므로 전자의 흐름에 기초하여 화학 반응을 이해하는데 필요한 기본 개념들을 화학 반응에 적용할 수 있게 하는 교수 학습 전략의 개발이 필요하다.

• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.62-75
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• 2001

The design and manufacture of injection molded polymeric parts with desired properties is a costly process dominated by empiricism including repeated modification of actual tooling. This paper presents and expert design evaluation system which can predict the mechanical performance of a molded product and diagnose the design before the actual mold is machined. The knowledge-based system synergistically combines a rule-based expert system with CAE programs. An iterative boundary pressure reflection method(IBPR) is developed to automate the cavity filling simulation program and to predict thermo-mechanical properties of a molded part precisely. Mathematical models of weldline and frozen-in molecular orientation are established to determine the spatial variation of microstructural anisotropies of a molded part from the result of cavity filling simulation. The strength ellipse is devised as and index which represents th spatial distribution of the microstructural anisotropies of a molded part, Heuristic knowledge of injection molding, flow simulation, and mechanical performance prediction is formalized as rules of an expert consultation system. The expert system interprets the analytical results of the process simulation, predicts the performance, evaluates the design and generates recommendations for optimal design alternative.

• 성인간호학회지
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• 제16권2호
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• pp.222-232
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• 2004

Purpose: The purpose of this study was to identify the change in foot care knowledge, self care behavior, and physiologic indexes after foot reflexomassage education program, and the related factors. Method: Data were collected from 20 patients who were visited out patients clinic. The change and difference were analyzed with non-parametric statistics. Result: There were significant differences in foot care knowledge(P=.001), self care behavior(P=.000), dosalis pedis blood flow volume (P=.011), skin temperature of foot(P=.001), dorsalis pedis pulse(P=.000), capillary filling time of foot (P=.000) between pre and post. The level of changes of foot care knowledge was significant differences according to admission experience (P=.049), and negative related to systolic blood pressure(P=.028). The level of changes of self care behavior was related to age(P=.049), that of dosalis pedis blood flow was significant difference according to smoking(P=.042), that of skin temperatureof foot(P=.002) and dosalis pedis pulse(P=.038) were significant difference according to weight. The level of changes of capillary filling time of foot was related to diagnosis period(P=.014). Conclusion: Foot-Reflexo-Massage education program is an effective nursing intervention to promote foot care in diabetic patients. And the related factors can be recommended for the management of diabetic patients.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.158-165
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• 1996

The knowledge of air flow in an engine room has become more and more important in recent car design. The fluid flow in the engine compartment was investigated by numerical analysis. Due to the complex geometry of the engine compartment, mesh generation is a time-consuming job. In this research, the "ICEM" code was used to generate meshes by the Cartesian mesh model. The Reynolds-averaged Navier Stokes equations, together with the porous flow model for radiator and condenser, were solved. Computation was performed for the steady, incompressible, and high speed viscous flow, adopting the standard K-ε turbulence model. The "STAR-CD" code was used as a solver. The effect of car front openning area on the flow in engine room was also investigated.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.441-447
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• 2005

The present study is aimed at understanding the flow physics associated with a safety valve applied to LNG ship engines. One-dimensional gasdynamic analyses and axisymmetric, compressible Navier-Stokes computations have been carried out to provide a qualitative and quantitative knowledge base for an effective design of the safety valve. Gasdynamic forces and thrust coefficients are obtained regarding a change in chamber pressure and distance between the nozzle exit and valve sheet which are major parameters to offer a variation in the flow feature. The present results show that the control of the passage area between the nozzle exit and valve sheet can attenuate the strength of shockwave generated in front of the valve sheet, which causes harm to stable system operation.

• Archives of Pharmacal Research
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• 제2권1호
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• pp.1-8
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• 1979

The flow rate of various sand through circular orifice can be measured from a knowledge of a few easily measurable properties of the system. These are the orifice column and particle diameters, the angle of inclination of the orifice with the horizontal and an angle of repose of the granular sand material. Straight lines were obtained when the logarithm of the flow rate was plotted versus the logarithm of orfice diameter. No influence of excessive compaction and bed height was observed and the flow rate increased with decrease of particle diameter. The profile of flow developed the edge of the aperture in a way independent of its size. Linear relationship was observed between the angle of inclination of the orifice and the flow rate.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.2116-2124
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• 2003

An experimental study providing additional knowledge of quasi-conical symmetry in swept shock wave/turbulent boundary-layer interactions is described. When a turbulent boundary layer on the flat plate is subjected to interact with a swept planar shock wave, the interaction flowfield far from fin leading edge has a nature of conical symmetry, which topological features of the interaction flow appear to emanate from a virtual conical origin. Surface streakline patterns obtained from the kerosene-lampblack tracings have been utilized to obtain representative surface features of the flow, including the location of the virtual conical origin. The scaling law for the sharp-fin interactions suggested by previous investigators has been reexamined for different freestream Mach numbers. It is noticed that the scaling law reasonably agrees with the present experimental data, however, that the law is not appropriate to estimate the location of the virtual conical origin. Further knowledge of the correlation for the virtual conical origin has thus been proposed.

• 소성∙가공
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• 제1권1호
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• pp.20-32
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• 1992

This paper describes some research of Computer-Aided Process Planning and Die Design of Hot Forging for axisymmetric parts produced by the press. An approach to the system is based on knowledge based system. The system has been written in AutoLisp with personal computer. Knowledges for process planning & die design are extracted from the plasticity theories, handbooks, relevent references and empirical know-how of field experts in hot forging companies. The developed system is composed of five main modules, such as input module, process planning module, die design module, flow simulation module and output module which are used independently or in all. The final output is generated in graphic from. The developed system which aids designer provides powerful capabilities for process planning and die design of hot forging. This system also provides approximate flow pattern.