• 한국재료학회지
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• 제11권12호
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• pp.1057-1062
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• 2001

We investigated the change of mechanical properties for TiNi shape memory alloy by heat treatment. 6061Al matrix composites with TiNi shape memory alloy as reinforcement were fabricated by vacuum casting. TiNi alloy has the maximum tensile strength at 673K treated and there is no change of tensile strength and hardness at 448K treated. The composites, prepared by vacuum casting, showed good interface bonding by vacuum casting. It was about 3$\mu\textrm{m}$ of thickness of the diffusion layer. Tensile strength of the composite was in higher than that of 6061Al alloy as increased value of about 70MPa at room temperature and about 110MPa at 363K. We thought that the increase of the tensile strength at 363K was due to reverse transformation of the TiNi shape memory alloy.

• 한국분말재료학회지
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• 제6권4호
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• pp.307-313
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• 1999

The effect of carbon content on the shape of WC grains dispersed in the Co-rich matrix during liquid phase sintering of WC-35%Co hard metals has been determined. The shape of WC grains was observed using SEM stereography after removing cobalt matrix with boiling hydrochloric acid solution. The WC grains changed from hexagonal to trigonal prism as the carbon content increased in the two-phase region of(WC + $\beta$ - Co), while the morphology of WC grains changed from trigonal to hexagonal shape as the carbon content decreased. The morphology of WC grains changes reversibly along with carbon loss or carbon pick-up. Morphology change of WC grains is attributed to crystal structure of WC, which has an asymmetric array of carbon atoms. There are two types of prismatic planes having different numbers of broken W-C bonds in WC grains. It is scrutinized that as the carbon content increases, the high energy prism planes grow fast and the crystals change from hexagonal to trigonal shape. On the other hand, when the carbon content decreases, the high energy prism planes are dissolved accompanying split of (100) plane into (101) and (101) planes.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.341-345
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• 2005

Structural Dynamics Modification (SDM) is a very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material properties and shape of structure. Among those of SDM technique, the method to change shape of structure has been mostly relied on engineer's experience and trial-and-error process which are very time consuming. In order to develop a systematic method to change structure shape, surface grooving technique is studied. In this work, the shape of base structure was modified to improve its dynamic characteristics such as natural frequencies via surface grooving technique. Grooving shape was formed by mergingthe neighboring small embossing elements after analyzing frequency increment sensitivities of all the neighboring emboss elements. For this process, Criterion Factor was introduced and the initial grooving was started from the element having highest strain energy and the grooving is expanded into neighboring element. The range of targeting grooving area to check its frequency variations restricted to their neighboring area to reduce the computation effort. This surface grooving technique was successfully applied to a hard disk drives (HDD) cover model to raise its natural frequency by giving some groove on its surface.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4513-4532
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• 2014

Motivated by the Weber's Law, this paper proposes an efficient and robust shape descriptor based on the perceptual stimulus model, called Weber's Law Shape Descriptor (WLSD). It is based on the theory that human perception of a pattern depends not only on the change of stimulus intensity, but also on the original stimulus intensity. Invariant to scale and rotation is the intrinsic properties of WLSD. As a global shape descriptor, WLSD has far lower computation complexity while is as discriminative as state-of-art shape descriptors. Experimental results demonstrate the strong capability of the proposed method in handling shape retrieval.

• 한국정밀공학회지
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• 제13권9호
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• pp.54-61
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• 1996

Because of its high energy density, the use of shape memory alloys(SMA) in designing microactuatiors is gaining much attention in recent years. Shape memory alloys can undergo a shape change at a low temperature with a small applied deformation force, and retain this deformation until they are heated, at which point they return to the original shape. This is called the shape memory effect(SME), and a plethora of alloys show this effect. Among them, TiNi-based alloys have relatively high electrical resistivity, which to develope helical-shape memory springs. These springs are used to develop fast protatonist/antagonist configuration actuators. The developed actuator has an actuation speed of 1 mm per 15 .approx. 20 ms and a minimum operating period of 2 sec.

• 건축역사연구
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• 제16권1호
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• pp.69-82
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• 2007

[ $\sqcap$ ]' shape of Jeonnam Area has not been well-known so far. This study is about when, how and on what type the '$\sqcap$' shape had settled among many 'ㅡ' shape houses. The Anchae of Jeonnam Area which appeared 17C. contrasts with 'ㅡ' shape. Especially, the head family's house might have been expected to develop with special difference. 'ㅡ' shape had been built much more than the '$\sqcap$' shape around 20C when modernization had been ripen. It was big event that '$\sqcap$' shape, the head family's house, had been pulled down and then 'ㅡ' shape had been newly built. (Ui Seong-ryeol house) The reason why 'ㅡ' shape had been built instead of '$\sqcap$' shape might be that people accepted the change of 'modernization', that is to say, people accepted convenience and opening. The plan of '$\sqcap$' shape consists of Daecheong and Anbang at the center of Momche, and Jageunbang and Jangji at both sides. In the '$\sqcap$' shape, the center of Momche is wide dand light unlike 'ㅡ' shape. Unjoru, Nogudang, Yundoseo house have long wing and have more encircling Anmadang than other houses, which are well known for a house for a man of noble birth.

• 한국의류학회지
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• 제44권2호
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• pp.224-236
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• 2020

In this study, the 4th (1997) and 6th (2013) direct measurements of Size Korea compared the changing shape of women between the ages of 12 and 18. Comparing the items of height and length, the height and shoulder height were significantly reduced, the waist height was not significantly different, and the height of the upper hip was significantly increased, resulting in a smaller upper torso ratio and a higher lower torso rate. The width and thickness associated with human obesity, the circumference items and obesity levels often increased significantly with the change of the times, indicating that the overall body size was increased and that the chest area was changed to a cylindrical shape with changes in the breast equilibrium. Comparing agespecific measurements with graphs analyzing the trend of change in growth, the results showed that the change in 1997 was minimal since age 14; however, a continuous increase was achieved in 2013 that corresponded to the age at which growth is complete. The results of these studies are expected to be used as basic data to predict pattern design, body implementation, and trends in shape changes for young women.

• 한국실내디자인학회논문집
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• 제25권2호
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• pp.41-49
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• 2016

The purpose of this study is to analyze the change and to compare to the difference of 'selective elements' and 'space-memory' focusing on the theory, 'selective attention' through the survey results. In this study, In this study, the lighting is considered a important factor in the change of 'selective elements'. this survey is to find the selective elements of participants and to measure the spatial sensitivity of respondents through 'self- test'. The analysis in this study is conducted by descriptive statistics, t-test and one way ANOVA by SPSS program 22. The results of this study are as following; Firstly, 'attention-element' could be classified with 4 types, 'shape', 'material', 'contrast' and 'combination'. 'shape' could divide into 'structure' and' furniture and object'. In case of 'material', it could section with 'pattern' and 'color'. Secondly, through the results of study, 'attention-element' is different each space during the day in detail. But we could know that 'shape' is the important element of the 'attention-elements' during the day through comparison of this result. That means users consider this as a important factor when they evaluate the space. Therefore, it is effective way designers to consider 'shape' as the first element when they want to conduct the special sensitivity of users in the space through planning. On the other hand, what selective elements of users are different by the lighting situation should be acknowledged by designers. And they should think the kinds of selective elements are more various when lighting turns on than turns off.. Thirdly, through the results such as the meaningful difference of space-memory of users according to the change of 'attention-elements', designers should judge about which kind of feeling of users to the space do you want lead in the design process. For the effective feedback between spaces and users to induce the same emotion of users, designers need to consider the unified design and the individual design both. Also, we will regard the differences in the users' emotion to the space according to the lighting situation when we design the space.

• 대한건축학회논문집:계획계
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• 제35권8호
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• pp.3-14
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• 2019

The research is to track the morphological transformation of residential towers of apartment complexes in Busan. Though apartment is one of the most important components in Korean society, it has not drawn enough attention from academia as well as the public, especially regarding its shape. In result, its morphological change has barely been recognized. Instead, negative, but superficial, evaluation has become dominant tendency to deal with the shape of apartment tower. There are numerous 'partial' evidences to inform the morphological change of apartment plan type, and understanding the change is critical since morphological resultant reflects culture, politics, economy of a society. The research has been done on the 261 apartment complexes built through 2016 in Busan. The analysis shows that $I^0$ type, to represent 'typical boring architectural shape' of Korean apartments, has been dominant until the year 2000. However, its portion has become drastically decreased since the mid-2000. Composite plan type, the geometrical precedents of which had never been existent, emerged in the mid-2000, and this phenomenon may symbolize the change of morphology of apartment. When tower plan types are grouped together according to geometrical shape, three types, I-type, L-type and Y-type, take the most of residential towers, explaining 97% of the total. As expected, I-type is the most dominant, but its influence has decreased as time passes. Y-type might become one of the most important type in the period V. L-type has become the leading type in the Period VI to exceed I-type by 12 percent.

• 대한기계학회논문집A
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• 제35권7호
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• pp.821-826
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• 2011

CAE 기반 구조최적설계법인 위상최적설계와 형상최적설계를 크레인의 경량화에 적용하였다. 붐은 단면 형상을 설계 변수로 변화시키면서 질량의 최소화를 최적설계의 목적함수로 하고 붐의 정적강도와 동적강성이 초기 모델의 성능에 비해서 저하되지 않아야 한다는 제한조건을 설정하였다. 구조해석 및 최적설계는 상용소프트웨어인 Hyperworks를 이용하여 수행하였으며 붐의 단면 형상의 변형에 따르는 요소망의 변동은 모핑 기능을 사용하여 수치 안정성을 확보하였다. 붐의 지지부는 초기 모델을 단순화시킨 설계 영역을 설정하고 이를 삼차원 솔리드 요소로 이산화한 후 위상최적설계를 수행하였다. 최적설계 결과 시스템의 전체 동적, 정적 강성을 저하시키지 않은 채로 붐은 19%, 지지부는 17% 경량화시킬 수 있었다.