• 대한기계학회논문집A
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• 제29권8호
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• pp.1078-1084
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• 2005

The relationship between fatigue crack opening behavior and the reversed plastic zone sizes is studied. An elastic-plastic finite element analysis (FEA) is performed to examine the opening behavior of fatigue crack, where the contact elements are used in the mesh of the track tip area. The smaller element size than reversed plastic zone size is used fer evaluating the distribution of reversed plastic zone. In the author's previous results the FEA could predict the crack opening level, which crack tip elements were in proportion to the theoretical reversed plastic zone size. It is found that the calculated reversed plastic zone size is related to the theoretical reversed plastic zone size and crack opening level. The calculated reversed plastic zone sizes are almost equal to the reversed plastic zone considering crack opening level obtained by experimental results. It can be possible to predict the crack opening level from the reversed plastic zone size calculated by finite element method. We find that the experimental crack opening levels correspond with the opening values of contact nodes on the calculated reversed plastic zone of finite element simulation.

• 자원환경지질
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• 제41권2호
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• pp.183-199
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• 2008

본 연구에서는 구룡광산에 적치된 광미층으로 부터 채취된 대표 비교란 코어시료를 대상으로 체계적인 물리 화학적 및 광물학적 특성을 심도별로 정량적으로 파악, 중금속 거동 핵심 영향요소를 기준으로 광미층 수직분대를 시도하고, 이를 기초로 광미층 비포화대-포화대에 걸친 원소 거동과 지화학적 조건과의 상관모델을 제시하고자 한다. 구룡광산의 대상 광미층은 화학적으로 지하수면을 경계로 상부층 구간에서의 낮은 pH(4)와 20wt.% 이상의 높은 $Fe_2O_3$ 및 $SO_3$ 함량에 의해 특징지어진다. 물리 화학적 및 광물학적 분석 자료를 고려하여 구룡광산 광미층을 심도증가에 따라 복토층, jarosite zone, Fe-sulfate zone, Fe-oxyhydroxide zone, gypsum-bearing pyrite zone, calcite-bearing pyrite zone, soil zone(광미층 집적 이전 토양층), weathered zone 등 7개분대로 구분할 수 있으며, 새로 생성된 이차광물상의 특성을 고려할 때 지하수면을 기준으로 상부층을 산화대(oxidation zone)로, 하부층을 비산화대(unoxidation zone), 혹은 carbonate-rich primary zone으로 크게 대분할 수 있다. 본 연구결과를 기초로 구룡광산 광미층의 물리 화학적 및 광물학적 변화를 지하수면 상부층에서의 황화광물, 특히 황철석의 산화반응이 핵심요소가 되어, 이로 인한 pH 값의 감소, 일차광물의 용해반응 및 원소 용출, 이차광물상 생성, 그리고 생성된 산의 탄산염 및 규산염광물에 의한 산-중화반응 등 일련의 지화학적 반응으로 설명할 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 사면안정학술발표회
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• pp.119-127
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• 2003

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are‘active zone’and‘passive zone’. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• 산업기술연구
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• 제22권B호
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• pp.103-108
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• 2002

This research was performed to investigate the generation and physico-chemical characteristics of municipal solid wastes. The results were as follows: i) The generation rate and bulk density were 0.157 kg/cap/d and 147.8 g/L in residential zone, respectively. In non-residential zone, the generation and bulk density were 1.71 kg/cap/d and 85.6 g/L, respectively. Consequently, bulk density of non-residential zone was lower than that of residential zone. ii) The wastes consisted of 90% of combustibles and 10% of incombustibles in residential zone. And the wastes from non-residential zone was composed 85% of combustibles and 15% of incombustibles. iii) Water content was estimated at 47~50% in residential zone and restaurants. In non-residential zone, except restaurants, water content was in the range of 10~30%. Ash content was nearly 10% in overall zone.

• Journal of information and communication convergence engineering
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• 제8권3호
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• pp.339-342
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• 2010

An iris image pattern positioning with preserved edge detector, ring zone and clock zone, frequency distribution and overlay matching is presented in this paper. Edge detector is required to be powerful and detail. That is proposed by overlaying Canny with LOG (CLOG). The two reference patterns are made from allocating each gray level on the clock zone and ring zone respectively. The normalized target image is overlaid with the clock zone reference pattern and the ring zone pattern to extract overlapped number, and make a matched frequency distribution to look through a symptom and position of human organ and tissue. The iterating experiments result in the ring and clock zone positioning evaluation.

• 대한임베디드공학회논문지
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• 제11권3호
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• pp.135-141
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• 2016

Indoor zone-based services have continuously become popular by increased prevalence of smartphones. Bluetooth and ultrasound can be used for zone detection. However, bluetooth does not guarantee precise zone detection if the signal degrades due to the obstacles. Ultrasound can be easily forged by recording sound on the smartphone. For that reason, zone detection based on ultrasound has a security hole. To remedy each limitation, we propose an advanced zone detection method, that combines bluetooth and ultrasound. An authentication server issues a one-time password to the user over bluetooth. The user generates an ultrasound signal that encodes the password. In this manner, the proposed method ensures secure and accurate zone detection.

• 한국강구조학회 논문집
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• 제9권4호통권33호
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• pp.683-695
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• 1997

본 연구는 강제 라멘교각 접합부 panel zone의 전단거동특성에 대하여 검토한 것이다. 여기에서는 접합부 시험체 20개에 대한 재하실험 결과와 3가지의 FEM해석 모델에 대한 결과를 제시 하였다. 이와같은 실험및 해석결과를 비교 검토한 결과, panel zone의 강도와 변형 성능은 단면적비와 전단좌굴등에 의하여 감소하는 경향을 보이고 있음을 알 수 있었다. 따라서 본 연구에서는 이상의 결과를 기초로 panel zone의 강도와 변형성능에 대한 새로운 평가식을 제안하였으며, 또한 기존의 라멘교각 접합부에 대한 변형성능에 관해서 검토하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 사면안정 학술발표회
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• pp.235-239
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• 2000

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• 지구물리
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• 제8권1호
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• pp.39-43
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• 2005

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain istribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• 대한산업공학회지
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• 제22권4호
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• pp.689-703
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• 1996

In this paper, we evaluate the performance of zone-based registration. First, we propose a mobility function for single zone-based registration. And we establish the circumstances of multiple zone-based registration, which is based on the mobility function for single zone-based registration, and perform simulation programs for the circumstances. Using the simulation results, we obtain optimal N, the number of multiple zones which minimizes signalling traffic in radio channels. Results show that in most cases optimal N is 2. Multiple zone-based registration has less signalling traffic in radio channels than single zone-based registration and zone-based registration must be implemented as multiple zone-based registration.