• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.464-467
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• 2003

In this paper, to reduce the patch size of microstrip antenna, folded surface-type patch antenna is designed and fabricated. Size reduction could be achieved because of the downed resonant frequency by the extended current path passing along below the transformated patch surface. Comparison of the patch size at the 1.575 GHz between plane type(length 82 mm${\times}$width 90 mm) and "ㄷ"-shaped folded type is carried and comparision of frequency variation at the same patch size is carried. The result is like that the patch size was reduced than the plane type by 60 mm(73.17 %) at the same frequency. Therefore, it could be checked that "ㄷ"-shaped folded type antenna is advantageous than the plane type in size reduction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.151-152
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• 2022

When reinforcing an existing building with the Concrete Filled Tube(CFT) structure, it is impossible to form a diaphragm inside with the existing method. Therefore, in this study, a construction method was proposed so that the internal diaphragm could be welded on four sides by using a slot to transmit force.

• Explosives and Blasting
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• v.39 no.4
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• pp.12-21
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• 2021

In this study, a series of FEM numerical analyses was conducted to compare the resistance performance of concrete drainage protection facility to blast vibration. Two different types of ㅁ-shaped protection facility, which are suggested in the study, were compared to the traditional ㄷ-shaped one. In the analyses, the vibration resistances of the three protection facilities were evaluated under the varying conditions of the standoff distance from the explosion and charge weight per delay. As a result, it was found that the two proposed types of drainage protection facilities are superior to the traditional one in the vibration reduction performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.535-541
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• 2004

For housing estate of a new administrative capital city, Noise reduction method is a important design factor. As measuring a noise level of traffic noise according to separation from road, it can be created a quite housing estate. Analyzing of merits and demerits in sound barrier walls and tunnels can be proposed environment friendly soundproofing facilities. Number of measurement was performed to know what kind of layout of housing estate is good for noise reduction. Through this measurement, ㄷ shaped layout or parallel layout has the advantage of sound insulation rather than right angled layout. In this case (ㄷ shaped layout or parallel layout) buildings neighboring to the road should be designed to insulate sound. Evergreen trees should be planted between housing estate and road more than 30m (at least 7～8m) in order to reduce noise and have masking effects. If broad-leaved trees are planted more than 30m, approximately 10dB noise is reduced and 2～4dB if 7～8m. Roads in the estate should be designed considering pedestrians first, and special roads for moving and ambulance should be designed as skew road, if possible. The result shows that 15$^{\circ}$-sloped‘S’road reduces 1～2dB noise and 30$^{\circ}$-sloped road reduces 4～7dB. If noise barrier is inevitably installed, it should be designed to go well wit neighboring environment so as to install Environment Friendly Noise Barrier using materials and trees including wood and soil. Through this study the results are used to guideline for construction of environment friendly housing estate

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.152-176
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• 2022

This paper, a basic study on the restoration of arrow quivers during the Three Kingdoms Period, aimed to contribute details to the existing plan to restore the arrow quivers. The arrow quivers of the Three Kingdoms Period consist of a pouch for holding arrows and a backpiece. However, the two parts do not remain, and only metal parts have been excavated. The excavated arrow quivers were classified into three types for restoration. Centered on the pouch, the quivers were classified into type 1 made up of a W-shaped part and ㄷ-shaped part, and type 2 with only the band-shaped piece identified. Type 3 is similar to type 2, but it is assumed to be a separate type where an iron band extending from the hanging piece(吊手金具) is connected to a band-shaped piece. Before proposing a restoration plan for the three types of arrow quivers, the location of the hanging piece (吊手金具) and the observation of organic matter were reflected. In addition, such details as the location of the hanging piece (吊手金具), which cannot be identified by the excavation status alone, were derived from the ways of wearing the arrow quivers observed in the Joseon Dynasty, Shosoin (正倉院), and Haniwa (埴輪) in Japan. Referring to the existing record on the transformation of arrow quivers based on the hanging piece (吊手金具), the arrow quivers change from type 1 to types 2 and 3 in this paper. However, some of types 2 and 3 maintain the ways of wearing of type 1, and there were cases where the old-fashioned parts were kept. In particular, in Haman (咸安), it was confirmed that the typical type 1 was buried up until late periods.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.113-122
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• 2007

Houses in Jeju city are divided into separated types and combination types of household affairs space. Other special types are separated-kitchen type. Separated household affairs space type is mostly built. Separated household affairs space type were sitting room + Gopang separate type and separate sitting room type. Combination household affairs space type made from sitting room, kitchen, Gopang and Chabang(Dinning room) put together as space differentiation, also into classes sitting room + kitchen + Gopang + Chabang type, sitting room + kitchen + Chabang type, sitting room + kitchen + Gopang, sitting room + kitchen type by combination household cares space type. Separated-kitchen type was one of the special type from separated-kitchen type of traditional housing, and type with continuous. Houses in Jeju city were 3 kan type and 4 kan type. 4kan type was mostly built. ㅡ shape is kept as plan shaped of straight shape, and roof shape is showed as ㅡ shape gathering roof. ㅡ shape + part projection type talls part projecting type as happened in Gopang, and Chabang. Roof is gathering roof, and when it is showed ㄱ shape by Gopang, Chabang, and kitchen are projected. ㅡ shape + total projection shape is one of the room become totally projected by Gopang and Chabang, can be happen with small room or kitchen, and roof as gathering roof shaped with ㅡ shape, ㄱ shape, ㄷ shape, unsystematic ㄹ shape, and various shapes.

• Transactions of Materials Processing
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• v.14 no.3 s.75
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• pp.251-256
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• 2005

3-D micro structures and micro tools were fabricated using Micro Electrical Discharge Machining (MEDM). To make micro structures, micro electrical discharge milling process was applied. During micro electrical discharge milling, electrode (tool) worn in the both axial and radial direction. To compensate tool wear which has significant influence on machining accuracy, machining path overlapping was proposed. Machining characteristics of micro electrical discharge milling was investigated in considering of depth of cut and capacitance of discharge circuit. Micro complex shaped tools were also fabricated using REDM (reverse electrical discharge machining). Sacrificial electrodes were machined through electrical discharge milling process and were used as electrode to make micro tools. Using this process several micro tools shape of 'ㄷ', 'ㅁ' and 'o' were fabricated. With these complex shaped tools, micro machining was successfully applied repeatedly.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.11a
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• pp.255-259
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• 2004

3-D micro structures and micro tools are fabricated using MEDM (Micro Electric Discharge Machining). To make micro structures, micro electro discharge milling process is applied. During micro electro discharge milling, electrode (tool) wears both axial and radial direction. To compensate tool wear which influences significantly machining accuracy, overlap machining path is proposed. Machining characteristics of micro electro discharge milling is investigated in considering of depth of cut and capacitance of discharge circuit. Micro complex shaped tools are fabricated using REDM (reverse electro discharge machining). Sacrificial electrode is machined through electro discharge milling process and is used as electrode to make micro tools. Using this process several micro tools shape of 'ㄷ', 'ㅁ' and 'o' are fabricated. With these complex shaped tools, micro machining is successfully applied repeatedly.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.468-473
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• 2004

본 연구에서는 기존의 ㅡ자형, ㄴ자형, ㄷ자형 조파시스템이 경사진 방향으로 가동될 때 발생되는 에너지의 불연속성으로 인한 회절철상이나 구조물에서 반사된 파가 조파판에서 발생하는 재 반사 철상의 단점을 보완할 수 있도록 곡선형태의 조파판을 배치하여 수치실험을 행하였다. 조파판을 곡선형으로 배치시켜 실험 대상물에서부터 반사된 파가 가능한 조파판에 직각으로 부딪치도록 유도하였다. 편미분 격자생성기법을 도입하여 구성된 곡선형 격자망에서 Copeland(1985)의 완경사 방정식을 이용하여 수치해석 하였다. 우선, 1차원 실험영역에서 파를 생성하여 대상구조물에서 반사되어 돌아온 반사파 성분을 조파판에서 흡수하면서 입사파를 생성하는 현상을 재현하였다. 그 후, 실험영역을 2차원으로 확장시켜 조파판을 곡선형으로 배치하여 수치 실험하여 진행파와 회절파의 중첩으로 고안된 해석해와 수치 해를 비교하려다. 그 결과, 기존의 조파시스템에 비하여 에너지 불연속선에서의 회절 현상도 발생하지 않고 반사파 성분을 효율적으로 흡수하는데 효과적임을 알아냈다.

• The Journal of the Korean dental association
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• v.53 no.7
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• pp.450-456
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• 2015

Even the adult cleft lip and palate patient who has not had timely treatment during the growth period, can be treated with orthodontic treatment without the necessity of orthognathic surgery if only the patient is treated under correct diagnosis and fitting appliances. Initially, maxillary arch form is established by constructing trifocal circles. Posterior region can be expanded and derotated laterally with pentahelix and anterior teeth are aligned with Tiggle brackets and "ㄷ"-shaped spring. Thereafter, anterior and posterior regions are consolidated. Mandibular intercanine width should be adjusted to maxillary intercanine width which was unavoidably reduced. Mandibular anterior tooth extraction will be helpful to attain proper mandibular intercanine width and better anterior dental showing.