• 한국생산제조학회지
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• 제23권3호
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• pp.230-236
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• 2014

Wafer level package technology is added to the surface of wafer circuit packages to create a semiconductor technology that can minimize the size of the package. However, in conventional packaging, warpage and fracture are major concerns for semiconductor manufacturing. We optimized the wafer dam design using a finite element method according to the dam height and heat distribution thermal properties. The dam design influences the uniform deposition of the image sensor and prevents the filling material from overflowing. In this study, finite element analysis was employed to determine the key factors that may affect the reliability performance of the dam package. Three-dimensional finite element models were constructed using the simulation software ANSYS to perform the dam thermo-mechanical simulation and analysis.

• 한국주조공학회지
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• 제19권5호
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• pp.393-402
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• 1999

The reheating of the billet in the semi-solid state as quickly and homogeneously as possible is one of the most important aspects. From this point of view, an optimal design of the induction coil is necessary. The objective of inductive coil designsi a uniform induction heating over the length of the billet. The effect of coil length, diameter, the gap between coil surface and billet and axial position of the billet on temperature distribution of billet has been investigated. These design parameters have an important effectiveness on the electro-magnetic field. Therefore, in this study an optimal coil design to minimize electromagnetic ed effect will be proposed by defining the relationship between billet length and coil length. In particular, key point in induction heating process is focussed on optimizing the coil design with regard to the size of the heating billet and the frequency of induction heating system. After demonstrating the suitability of an optimal coil design through the FEM simulation of the induction heating process, the results of the coil design are also applied to the reheating process to obtain a fine globular microstructure. Its considered that the reheating conditions of aluminum alloys for thixoforging and a new CAE model of the induction heating process are very useful for thixoforging practitioners including induction heating ones.

• Earthquakes and Structures
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• 제13권5호
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• pp.443-454
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• 2017

When eccentrically braced steel frames (EBFs) are in the desired failure mode, links yield at each layer and column bases appear plastically hinged. Traditional design methods cannot accurately predict the inelastic behavior of structures owing to the use of capacity-based design theory. This paper proposes the use of performance-based seismic design (PBSD) method for planning eccentrically braced frames. PBSD can predict and control inelastic deformation of structures by target drift and failure mode. In buildings designed via this process, all links dissipate energy in the rare event of an earthquake, while other members remain in elastic state, and as the story drift is uniform along the structure height, weak layers will be avoided. In this condition, eccentrically braced frames may be more easily rehabilitated after the effects of an earthquake. The effectiveness of the proposed method is illustrated through a sample case study of ten-story K-type EBFs and Y- type EBFs buildings, and is validated by pushover analysis and dynamic analysis. The ultimate state of frames designed by the proposed method will fail in the desired failure mode. That is, inelastic deformation of structure mainly occurs in links; each layer of links involved dissipates energy, and weak layers do not exist in the structure. The PBSD method can provide a reference for structural design of eccentrically braced steel frames.

• 융합정보논문지
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• 제11권10호
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• pp.27-35
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• 2021

본 연구의 목적은 최근 다양성이 접목된 융합적이고 창의적인 교육이 가능한 공간의 필요성이 강조됨에 따라, 학교공간혁신사업의 하나로 사용자 참여설계에 의한 공간의 재구조화 수행을 목적으로 한다. 연구 내용은 부산 Y초등학교를 대상으로 사용자가 함께 참여하는 과정을 통해 소통하면서 다양한 요구사항과 구체적인 아이디어, 방안을 도출하고 적용해나가는 과정을 거쳐 최종 디자인에 이르는 과정을 거쳤다. 연구 결과 1~6학년의 획일화된 교육공간에서 벗어나 공간의 다양성을 추구하였으며, 혁신으로 만들어진 공간의 만족도를 위해 그 공간을 사용하는 다양한 사람들의 사용자 참여설계가 필수적임을 알 수 있다. 본 연구는 학년별 특성이 반영된 다양한 공간디자인 개발에 중점을 두고 있으며, 1인 1 캐비닛을 빌트인하여 개인적 공간을 확보했다는 것이 특징이다. 이와 같은 사용자 참여의 과정에서 다양한 의견을 수렴하여 조율하고 함축시킨 후 디자인으로 구체화시켜 공간에 적용함으로서 학교공간의 가장 바람직한 변화를 가져올 수 있을 것이다.

• Journal of Mechanical Science and Technology
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• 제16권8호
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• pp.1144-1153
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• 2002

A hybrid performance prediction method is proposed in the present study. A channel diffuser is divided into four subregions: vaneless space, semi-vaneless space, channel, and channel exit region. One-dimensional compressible core flow and boundary layer calculation of each region with an incidence loss model and empirical correlation of residuary pressure recovery coefficient of a channel predict the performance of diffusers. Three channel diffusers are designed and tested for validating the developed prediction method. The pressure distributions from an impeller exit to the channel diffuser exit are measured and discussed for various operating conditions from choke to nearly surge conditions. The strong non-uniform pressure distribution which is caused by impeller-diffuser interaction is obtained over the vaneless and semi-vaneless spaces. The predicted performance shows good agreement with the measured performance of diffusers at a design condition as well as at off-design conditions.

• 반도체디스플레이기술학회지
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• 제9권4호
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• pp.71-76
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• 2010

According to recent changes in industry for semiconductor devices, a low-temperature treatment has become a necessity. These changes relate to size refinement and the development of new materials. While variation in cooling efficiency does not affect the yield when using a high-temperature treatment, uniform cooling efficiency is necessary avoid "inconsistencies/bends" in low temperature treatments. However it is difficult to increase temperature stabilization in low temperature treatments. In this paper, using CFD (Computer Fluid Dynamics), we analyze and manipulate the design and input of the low-temperature system to attempt to control for temperature variations within the quartz tube, of which airflow appears to be a predominant factor. This simulation includes variable inputs such as airflow rate, head pressure, and design manipulations in the S.C.U. (Super Cooling Unit).

• Journal of Biosystems Engineering
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• 제28권1호
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• pp.35-44
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• 2003

This study was conducted to develop proper model for cold storage facility that could of for uniform heat movement and air movement f3r green grocery and improve improper design of the existing container-type cold storage facility. For that reason, new model(dome-type) cold storage facility was developed using 3-D CFD(computational fluid dynamics) simulation. The size was 6m${\times}$6m${\times}$5m. Its size and configuration were same to simulation model. Unit cooler was designed to send cold air in 4 side ways. A dome-type cold storage facility showed uniform distributions of air temperature and velocity because cold air was forced to move down along the ceiling and the wall and then circulated to the unit cooler from the central part of the floor. Dome-type cold storage facility also showed by low wind velocity, below 1 m/s that could minimized cold damage and quality deterioration.

• 가정과삶의질연구
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• 제26권2호
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• pp.143-154
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• 2008

This study intended to provide information which gives a way for students and their parents to be satisfied with student costume purchase by showing differences between their satisfactions and repurchasing intention according to school uniform purchase type. Total 280 questionnaires were distributed to the first year students at a private middle school in Seoul and 133 of copurchase cases and 120 individual purchase cases were collected and analyzed. The comparing results between parent satisfaction and repurchasing intention were summarized as follows. First, parent satisfaction of individual purchase and of co-purchase had been evaluated. As a result of the analysis of satisfaction by the five factors, individual parent buyers had higher satisfaction in brand, quality, design, and service except price. The largest different factor between both customers was quality satisfaction. Secondly, the individual buyers showed higher repurchasing intention than co-purchasing buyers. This result meant that individual purchasing group showed higher satisfaction. Lastly, when the relationship between satisfaction and repurchasing intention of each buyer group was examined, the level of satisfaction was positively associated with the repurchase intention of co-purchase.

• 한국의류학회지
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• 제31권1호
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• pp.11-20
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• 2007

The purpose of this study is to analyze the various signs seen on TV commercials for school uniforms since year 2000, thus uncovering the connotative meanings in them. For this study, the semiotic approach has been used. The signs seen on the TV commercials are separated into linguistic and visual signs. They are found to have symbolic connotations. The results are as follows: First, there are plenty of signs expressing the sense of belonging to the student group and sense of conformity to his or her peer group. They are intended to garner their collective identity in the peer group of teenagers. Second, the TV commercials express the self that is realizing one's value dynamically. The frequent designation of 'I', 'me' and 'myself' represents that I am at the center of the world. Furthermore, the suggestion of diverse student roles beyond mere academic pursuits symbolically shows the ideal self that most teenagers wish to have. Third, the TV commercials implied a commercial ideology. That is expressed in the emphasis on aesthetic value that teenagers can realize their self only by consuming expensive school uniform brands. Forth, there are many signs related to appearance and appearance care. They are expressed with very specific signs such as 3 : 7 proportion, long legs, small face, and so on. Repeating or emphasizing the importance of looks and a certain brand name as the tool to accomplish better looks indicates that it contains the ideology of appearance management.

• 한국의상디자인학회지
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• 제11권1호
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• pp.123-132
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• 2009

Our government has declared the "Synthetic Project for Promoting Han-style" to industrialize and globalize the original form of Korea traditional culture. Han-bok, our traditional folk costume is one of the main subject of this project. However it is the global trend not to wear their traditional folk costume. And so, the number of people wearing Han-bok, our traditional folk costume is also getting gradually decreased in Korea. For Han-style Promoting Project in the future, it is one of the most efficient way for the middle and high school students to motivate and increase the interest about Han-style and Han-bok as the middle and high school uniforms. Adolescent middle and high school students think very important their appearance. Especially, Korean middle and high school students spend a lot of time in school, and so school uniforms are very influential in their mental and physical aspects. Fabrics for this study, they were woven twill with 3 kinds of fabric patterns from the motif of Baekje relics. The colors of fabrics is the blue and brown used in general school uniform, the yellow and red used in Han-bok. Considering the school uniforms, fabric patterns adapted the similar color matching method for not to be found cleary and designed the fabric pattern's one-repeat size is $4{\times}4cm$.