• Journal of international Conference on Electrical Machines and Systems
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• 제2권3호
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• pp.295-299
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• 2013

This paper presents the new structure of a spindle motor for hard disk drive (HDD). It can produce axial force as well as torque without a pulling plate or a pulling magnet required for the normal operation of a hydrodynamic bearing in rotating-shaft structure. The proposed models have different air gap length along the axial direction by changing the thickness of permanent magnet (PM). One has a single slope and the other has double slopes on the surface of PM. For the design of the proposed models, variables are defined and its effects on the motor performances are investigated by 3-demensional finite element analysis (FEA). The equi-performance curves are investigated for the main characteristics of the spindle motor such as generated torque, axial force and torque ripple ratio. The validity of the proposed models is verified by the feasibility study and performance evaluation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.170-173
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• 2003

In this paper, we proposed a new bulk LDMOS structure which can be used for RF application, and its fabrication steps were introduced. The simulated devices consist of three types: Bulk device, SLB(SOI Like Bulk), and SOI device. As a result of process and device simulation, we showed electrical characteristics, such as threshold voltage, subthreshold slope, DIBL(Drain Induced Barrier Lowering), off-state current, and breakdown voltage. In this simulation study, the lattice temperature model was adopted to see the device characteristics with lattice temperature during the operation. SLB device structure showed the best breakdown characteristics among the other structures. The breakdown voltage of SLB structure is about 9V, that of bulk is 7V, and that of SOI is 8V.

• 한국제4기학회지
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• 제22권2호
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• pp.1-5
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• 2008

Some reverse fault lines pass through the alluvial fans and west hill slope of Bulguksa mountains including Mt. Toham in the directions of N-S and NW-SE. The study area is known as relatively unstable, because of active faults. Assuming the record of earthquake in the Samguksagi, the architects in the construction of the Bulguksa temple should have recognized the possibility of breakdown from the earthquakes and the need for an unique structure against at that time. Against earthquakes, Greavee technique, a stonework construction technique following woothe one and use of Chushouok (Dongtleouok or Chumchaouok) were applied for the construction of Bulguksa temple. By designing the foundation stone with hole, a structure is prevented from motiff Ction that pillarsakdcede from a foundation stone in spite of horizontal load of earthquake while woot construction isaktrong frame at earthquake. The Bulguksa-temple isausually evaluated to be a beautiful architecture from the appeaultces like the weight balltced structure with unique decoration. ampressive architectures are beautiful in balance and harmony coming from the important and specific rolls in its own way by each part of whole structure. This beauty comes from the science.

• 화약ㆍ발파
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• 제24권2호
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• pp.41-50
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• 2006

화약을 이용한 지반굴착은 진동 및 소음 등의 공해가 필연적으로 수반되기 때문에 민원발생 및 주변 구조물에 영향을 미칠 수 있다. 특히, 발파작업 구간 부근에 지장물이 위치하게 되는 경우, 발파진동에 대한 안정성 평가는 매우 중요한 항목이 된다 발파진동안정성 평가 시 기존에는 시험발파를 통하여 대상지역의 발파진동식을 추정하고, 거리 및 장약량을 고려한 단순평가법이 많이 사용되어 왔으나, 이는 대상지역의 지형 및 지반조건을 현실적으로 고려하지 못한 방법이다 이를 보완하기 위해 최근에는 대상지역의 지형 및 지반조건을 연속체 또는 불연속체로 모사한 동적수치해석법이 적용되고 있다. 일반적으로 터널이나 비탈면 발파진동 수치해석시에는 다수의 발파공 모델링이 현실적으로 거의 불가능하여, 단일발파공, 특히 심발공에서 추정된 발파압력을 최종 굴착면에서의 등가압력으로 환산하여 발파하중으로 적용하게 된다. 이와 같은 이론적인 계산식이나 경험식에 의해 추정된 발파압력을 이용한 방법은 단일 발파공에서의 폭발압력에 대해 연구된 결과로서, 폭발상태를 이상적인 것으로 가정하고 폭발에너지를 구하게 된다. 따라서, 최종 굴착면에 적용된 등가압력은 지반조건을 고려하지 못하여 동일한 단면 및 발파조건에서는 동일한 발파하중이 산정된다. 즉, 기존의 발파하중 산정법은 대상지역의 지반조건을 고려하지 못하여, 해석결과의 신뢰도를 저하시키는 원인이 된다. 본 사례연구에서는 발파하중 산정 및 해석결과의 신뢰도를 제고하기 위하여, 대상지역의 시험발파시 획득된 실측진동파형을 이용한 발파하중 산정법을 통하여 비탈면 발파굴착시 주변 지장물의 안정성 평가를 수행하였다.

• 한국환경복원기술학회지
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• 제8권2호
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• pp.21-32
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• 2005

Questionnaire survey from 101 visitors and 77 specialists was carried out to establish the management plan on landscapes of the artificial structure constructed in valley within Bughansan National Park. When comparison was made between ground sill work structure and valley landscape, visitor group responded to the highest scores in valley landscape after planting of vine species in the bottom of the constructure, while specialist group responded to valley landscape after the removal of the constructure. When it made a comparison between revetment work constructure and valley landscape, visitor group responded to highest scores in valley landscape after planting of vine species in the top of the constructure, while specialist group responded to valley landscape after replacing concrete revetment by stone revetment constructure. When it made a comparison between fall work constructure and valley landscape, both groups responded to the highest scores in valley landscape after the removal of the constructure. According to the valley landscape analysis, artificial constructures built in water channel should be matched to adjacent landscape with the removal of concrete constructure. The slope of water channel should be considered to build fall work constructure.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1602-1610
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• 2005

In this study was investigated and analyzed of damage characteristics for infrastructures by typhoon that have been many occur. The objective Structures were the road and hydraulic structure. The road structure was included the cut-slopes, retaining walls and bridges. The hydraulic structure is divided with the dike, small-scale dam, reservoir and floodgate. The analysis result of the bridge damage cause is river bottom height increase and passage ability decrease. The principal damage reasons of the cut-slope structure are weakening the ground due to the localized torrential downpour and drainage defective. Also, the principal damage reasons of the small-scale dam, reservoir, dike and the floodgate are continuous collapse of dike beside the floodgate.And we divided a typhoon damage occurrence cause with artificial and natural. As the result of analysis, the many damage occurrence cause will be removed by system improvement and technical development.

• 건축역사연구
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• 제19권4호
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• pp.7-19
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• 2010

'Lu' is one of the Korean traditional building structure. The architectural characteristics of the 'Lu' can be classified two types with its use. One is single building type and the other is a part of building type within building complex. This study is about the two-storied 'Lu' that was built on part of building complex. 'Lu' built in building complex such like Sa-chal, Hyang-gyo, Seo-won, Jae-sil, has the similar characters. 1. It is built by taking slope site. 2. Ii is one of four buildings that forms court yard. 3. It uses simple building structure on the purpose of openness 4. It can control view with using window. The column type of 'Lu' can be classified with 3 style. These are $5{\times}2$ Kan style, $3{\times}2$ Kan style and $5{\times}3$ Kan style. It would be assumed with the result of study that $5{\times}2$ Kan style has its origin in Hoe-Rang structure, $3{\times}2$ Kan style is originated from Joong-Moon(middle gate) structure, and $5{\times}3$ Kan is originated from Kang-Dang structure.

• 한국산림과학회지
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• 제76권3호
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• pp.206-217
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• 1987

서울의 남산자연공원(南山自然公園)의 식물군집구조(植物群集構造)를 분석하기 위하여 30개의 조사구(調査區)를 선정, 각 조사구에 $10{\times}10m$의 방형구(方形區) 5개씩을 설치 조사하였고, 또한 1978년과 1986년의 8년간의 식생군집변천(植生群集變遷)을 조사하기 위하여 17개 지점에 $5{\times}50m$의 "트란섹트"를 설치, 조사하였다. 남산(南山)의 현존식생(現存植生)의 비율은 아까시나무군집(群集) 29.39%, 신갈나무군집(群集) 21.25%, 소나무군집(群集) 17.58%이었다. 신갈나무림은 북사면(北斜面), 아까시나무림은 도로(道路) 등 시가지(市街地)와의 경계부(境界部), 소나무림은 동(東) 남사면(南斜面)에 주로 분포(分布)하였다. 녹지자연도(綠地自然度) 8, 7, 6의 비율은 각각 43.2, 7.8, 30.8%이었다. 남산삼림(南山森林)에서 소나무개체군(個體群)은 신갈나무, 팥배나무, 아까시나무, 산벚나무 등의 활엽수와의 경쟁에서 도태 되어 가고 있으며, 천이계열분석(遷移系列分析)에서도 소나무림은 신갈나무림으로 천이(遷移)가 진행되고 있었다. 지난 8년간의 식생구조(植生構造)의 변화(變化)는 종다양도(種多樣度)와 균재도(均在度)는 증가하였고, 우점도(優占度)는 감소(減少)하여, 하층(下層)의 종구성(種構成)이 다양(多樣)하여졌다. Raunkiaer 빈도계급(頻度階級)에서는 1986년이 1978년보다 A, E 급(級)이 증가하고, B 급(級)이 감소하여 남산(南山)의 식생(植生)은 동질화(同質化)되어 가고 있었다.

• 제어로봇시스템학회논문지
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• 제5권3호
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• pp.281-287
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• 1999

In this paper, a design method based on evolutionary programming for feedforward neural networks which have a single hidden layer is presented. By using an evolutionary programming, the network parameters such as the network structure, weight, slope of sigmoid functions and bias of nodes can be acquired simultaneously. To check the effectiveness of the suggested method, two numerical examples are examined. The performance of the identified network is demonstrated.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 봄 학술발표회 논문집
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• pp.29-33
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• 1991

This paper reports the application study of the ground reinforement under a buried pipeline subjected to differential settlement via a finite element modelling. The Soil-reinforrement interaction helps to mimimize the differential settlement between the adjoining pipe segments. The settlement pattern and deformation slope of a pipeline have been evaluated for a boundary condition at the joint between a rigid structure and apipeline. The analysis results are compared for both non-reinforied and reinforced cases to measure the effectiveness of the soil reinforcement for restraining the settlement of the pipeline.