• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.219-232
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• 2020

The result of efforts for the revitalization of traditional market have not been satisfied. The purpose of this study was to suggest implications on planning and design method for revitalization of the traditional market in Korean cities. For that, theoretical review and case analysis were conducted on public spaces in 'Quincy Market' and 'Granville Island Public Market'. The results of case analysis are as follows. (1) The various spaces and facilities that make up the traditional market show a synergistic effect through linkage. (2) Various public spaces for traditional market users have been made in market buildings and open spaces. (3) Food and beverages sold in traditional markets can be eaten in public spaces, and meetings, breaks, performances and events are held in public spaces. (4) A company or non-profit organization with unified executive power is in charge of or participating in market operation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.18-24
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• 2011

This paper presents that the yield strength of the pressure sensor with a double boss diaphragm structure can be improved as the grooves are formed at the corner of the diaphragm bridge. Generally the boss structure is widely used for the low-pressure sensor, of which the sensitivity is not enough in case of the small diaphragm size limited by a chip size constraint. The double boss structure pressure sensor exhibits a great sensitivity, but suffers from the low yield strength problem due to the high stress occurred at the corner of the diaphragm bridge to be limited in the operating range. ANSYS simulation is performed by changing the length of the groove from 0.5${\mu}m$ to 10${\mu}m$ at the corner of the diaphragm bridge of the double boss structure pressure sensor. The maximum stress is analyzed at the corner of the diaphragm bridge, the edge of the diaphragm bridge, and the position of the piezoresistive sensor. Consequently, in case the length of the groove from the edge of the diaphragm is 6${\mu}m$ or greater, the stress occurred in the corner of the bridge is less than the stress acting on a piezoresistive element.

• Journal of the Korean Society of Costume
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• v.60 no.6
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• pp.117-138
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• 2010

This study tries to analyse the type of sasanian crowns by looking into the icons and meanings of various motifs that changed the archetype and shape of the crowns, and the social and political factors that affected those motifs. Based on such analysis, the study is aimed at completing the periodic typology of the sasanian crown. For this study the literature research is combined with the empirical analysis of information. Korymbos which symbolizes globe represented the authority and power of the sasanian kings, but the motif with such meaning was replaced by star motif in the late-sasanian crowns. The basic motifs embellishing the sasanian crown represent Gods, which is interpreted as an attempt to symbolize the relations between Gods and kings. These motifs are found on each king's crown in a different and individual way, which seems because the kings at the time chose the motif that can symbolize their own political intention or spirit. At the early days of the sasanian dynasty, Korymbos motif was highly emphasized on the crowns, and was used throughout the end of the dynasty and then was replaced by star motif. From the mid-4th century, Crescent motif started to be used, which was always shown as the shape supporting Korymbos and star motif on it. Bird wing motif was intermittently used in the early and middle days of the dynasty, and was highly emphasized in the crowns of all the kings in the end of the dynasty. Star motif started to be used in the end of sasanian dynasty.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.897-904
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• 2012

The rifling design problem has continuous-type shape variables and an integral number of riflings. In addition, it requires considerable time for analysis because its behavior should be described by a nonlinear finite element model (FEM). Therefore, this study presents an efficient design process for rifling based on a design of experiment (DOE) approach. First, Bose's orthogonal array is used to represent 25 runs for four design variables including three shape variables and one integer variable. Then, nonlinear FE analyses are performed. Next, to minimize the bullet resistance without affecting the bullet velocity and bullet rotational angle immediately before a bullet leaves the gun barrel, a what-if design is performed. In the proposed what-if design, a functional including the design objective and constraints is constructed and effect analysis is performed by using the functional. It is found that the new design obtained from the what-if design shows better results than the current one.

• The Journal of the Acoustical Society of Korea
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• v.24 no.1
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• pp.21-28
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• 2005

In this Paper, the effect of stage ceiling height on the acoustic characteristics of rectangular concert halls are investigated. To find out the acoustic properties of audience area, A simple Boston Symphony Hall(BSH) model which is typically rectangular shaped was applied for computer simulation. A newly built rectangular concert hall with 400 seats was also chosen for a scale model $(1.2m{\times}0.68m{\times}0.31m)$ study and its computer simulation varing the stage ceiling height and the volume. The results show that RT increased as the stage ceiling was lowered and the difference rate of RT by its variance is from -0.09 to -0.06[sec/m].

• Journal of the Korea Convergence Society
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• v.2 no.2
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• pp.27-34
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• 2011

This study is making a product for the development of one process worm wheel of making a shape for gear for worm wheel without hobbing manufacturing process. Because of removing a hobbing process, plastic worm wheel for increased productivity and equivalent quality is produced in the result. As the result, this product is selling to Hyundai Mobis, Mando, TRW, KOYO/NSK/Showa(Japan), Delphai(America). The core technology and different strategy are as follows. The technology protection for molding of worm whee is currently patent process "Molding process of helical gear(No. 10-2008-0105908). Further patent procedure for "molding system for positioning decision of inserting boss is currently prepared. As gear molding procedure in hobbing machine without gear machining procedure, most of all, core development technology which is making a gear tooth is main topic. So that, in case of currently developed worm wheel, because core and mold base are not developed in the first procedure, gear is machining in hobbing M/C as the second procedure. In the later, patent for mold base structure will be prepared in this study results.

• Journal of Korean Society of Steel Construction
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• v.21 no.3
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• pp.267-275
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• 2009

This paper presents the behavior of column-removed double-span beams in welded steel moment frames and proposes a simplified nonlinear dynamic analysis method for the preliminary evaluation of progressive collapse potential. The nonlinear finite element analysis and the associated analytical study showed that the column gravity load and the beam span-to-depth ratio govern the maximum dynamic deformation demand of the double-span beams. Based on these results, the concept of a collapse spectrum, which describes the relationship between the gravity load parameter and the maximum chord rotation of the double-span beams, was newly proposed. A procedure for the application of the collapse spectrum to multi-story welded steel moment frames was then suggested. The inelastic dynamic finite element analysis results showed that the proposed method gives satisfactory prediction of the nonlinear progressive collapse behavior of welded steel moment frames.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.3
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• pp.76-82
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• 2010

In this paper, we develop Linguistic Model (LM) based on information granules as a systematic approach to generating fuzzy if-then rules from a given input-output data. The LM introduced by Pedrycz is performed by fuzzy information granulation obtained from Context-based Fuzzy Clustering(CFC). This clustering estimates clusters by preserving the homogeneity of the clustered patterns associated with the input and output data. Although the effectiveness of LM has been demonstrated in the previous works, it needs to improve in the sense of performance. Therefore, we focus on the automatic generation of linguistic contexts, addition of bias term, and the transformed form of consequent parameter to improve both approximation and generalization capability of the conventional LM. The experimental results revealed that the improved LM yielded a better performance in comparison with LM and the conventional works for automobile MPG(miles per gallon) predication and Boston housing data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.48-48
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• 2008

현재 압전재료로써 사용되고 있는 PZT계 세라믹스는 우수한 압전 및 유전특성으로 초음파 센서, 압전변압기, 액츄에이터, 필터, 레조네이터와 같은 여러 응용분야에 널리 사용되어지고 있다. 그러나 납을 60%이상 포함하므로 환경오염에 의하여 그 사용에 대한 규제가 강화되고 있어 최근에는 납을 함유하지 않은 무연 환경친화형 압전세라믹스가 주목받고 있다. 현재 무연 조성 세라믹스에는 텅스텐-브론즈 형, 비스머스 레이어형, 페로브스카이트 형 등이 이으며, 그 중 페로보스카이트 혈을 제외하고는 보통 소성법 조제시 낮은 압전특성을 갖는다. 그러므로 압전특성을 증가시키기 위하여 Hot pressing, Hot forging, RTGG(Reactive Template Grain Growth), SPS(Spark Plasma Sintering), 그러나 이는 무연 세라믹스의 대량생산 과정에서 어려운 문제를 가지고 있고, 저가격 관점에서 볼 때 보통소성법이 보다 바람직하다. 그래서 보통소성법으로 NKN세라믹스의 소결성을 향상 시키고 비교적 높은 압전특성을 얻기 위해서 $LiSbO_3$, $LiNbO_3$, $LiTaO_3$, alkaline-earth(Mg, Ca, Sr, Ba) 등을 첨가한 논문들이 보고되고 있으며, 이러한 재료들의 kp는 대략 0.3-0.4를 나타내고 있다. 따라서, 본 연구에서는 소결온도를 낮추고자 $Ag_2O$를 소결조제로 사용하였고 유전 및 압전특성을 높이고자 소결시간 변화시켜 시편을 제작하여 NKN 세라믹스의 유전 및 압전특성을 조사하였다.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.493-498
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• 2020

The fourth industrial revolution is the first topic thrown by Klaus Schwab at the Davos World Economic Forum in January 2016, meaning the next industrial revolution led by the Internet of Things (IOT), artificial intelligence (AI), robot technology and life sciences. In addition, in our lives, humans, computers and machines are connected organically, and organic relationships are evolving and developing at a furious rate in all areas of life. Since the 1953 armistice agreement, South Korea has remained in a state of confrontation with North Korea, and there have been continued fighting by the North, including naval skirmishes in the West Sea, artillery attacks on Yeonpyeong Island, the sinking of the Cheonan warship, and unmanned aerial vehicles and ankle mines. To prepare for such a local initiative, our military is constantly preparing and will have to strengthen its combat capabilities by developing and introducing advanced military equipment. After all, the military drone industry linked to the Fourth Industrial Revolution following the development of new war should continue its research on military drones in line with accurate diagnosis and the rapid development of future science and technology and IT technologies.