• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.117-126
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• 2011

The buckling assessment of plate panels described in common structural rules (CSR) is to be determined according to the buckling utilization factor with hull girder stresses calculated on net hull girder sectional properties. As the thickness requirement for the buckling assessment of plate panels is not explicitly given in CSR, a lot of time is spent to find the proper thickness of plate panels until reaching to an allowable buckling utilization factor. In this study, in order to reduce time and cost, the thickness requirement of plate panels satisfying buckling assessment was derived. The structural design system included with the thickness requirement for buckling assessment was developed. The system is called as Oil-tanker Automated Structural Investigation System (OASIS). The design result of longitudinal strength members using OASIS was verified by Nauticus Hull which is the rule scantling software of DNV. Finally, optimum design of a double hull tanker for the minimum weight using OASIS was presented.

• 대한지질공학회:학술대회논문집
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• 대한지질공학회 2005년도 정기총회 및 학술발표회
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• pp.101-106
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• 2005

일본 훗카이도와 그 주변 지역의 238개의 관측소에서 관측한 깊이 0~300km내에서 일어난 4050개의 지진 중 P파 64,024개와 5파 64,618개를 Kim과 Bae(2004)에 의해 개발된 3 성분 토모그래피에 이용하였다. Vp/Vs의 속도 이상대가 훗카이도와 그 주변 지역에서 명확하게 나타났다. Double Seismic Zone(DSZ)의 Seismic Planes는, 훗카이도 주변에서 지진 위험도가 높게 나타나는, 40~80Km의 깊이에서 훗카이도 아래로 태평양판이 섭입하는 것이 발견되었다. 모호 불연속면아래에서 높은 Vp/Vs 이상대의 발견은 Moriya(1994)에 의해 제안된, 쿠릴 열도(Okhotsk Plate 혹은 North American Plate)가 NE 일본 열도(Amurian Plate 혹은 Eurasian Plate)와 충돌하고, 동시에 태평양판이 훗카이도의 Central Tectonic Axis($142^{\circ}{\sim}143^{\circ}E$)와 Hikada Mountain Range(HMR) Corner를 따라 지체구조력의 균형을 이루는 두 개의 판 아래로 섭입하고 있는, 표면 삼중 충돌 가설의 증거이다. 낮은 Vp와 Vs는 장력을 나타내는 지진 메커니즘의 표현인 Central Tectonic Axis을 따라 동쪽과 서쪽에서 발견되었다. 이들 현상은 이 지역에서의 낮은 부게 중력 이상값과 일치한다. 이것은 왜 큰 지진의 대부분이 훗카이도의 3개의 지체구조력의 3중 접합점에 의해 지체구조력의 균형이 깨어지는, 훗카이도 바깥쪽에서 일어나는지 알 수 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.653-658
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• 2001

In this study, a new practical method of predicting the sound absorption coefficient for multiple perforated-plate sound absorbing system was developed using transfer matrix method. In order to validate the proposed method, the absorption coefficients calculated by transfer matrix method for single perforated plate were first compared with the absorption coefficients measured by SWR method according to different porosity, hole diameter, and thickness of the perforated plate. Based on the comparison results, transfer matrix method was further applied to double and triple perforated plates to evaluate the absorption coefficients. The experimental results showed that the absorption coefficients from transfer matrix method generally agreed well with the corresponding absorption coefficients from SWR method. However, due to the limitations of the impedance model used in this study, the measured values were differed with the calculated values for small porosity, hole diameter, and thickness in size of the perforated plate indicating the need of impedance model development for multiple perforated-plate sound absorbing system covering wide ranges of porosity, hole diameter, and thickness of the perforated plate.

• 전자공학회논문지
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• 제53권7호
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• pp.11-16
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• 2016

탄화규소(Silicon Carbide)는 와이드 밴드 갭 물질로써 실리콘(Si)에 비해 고전력, 고주파, 고온 소자용 반도체 물질로서 각광받고 있다. 탄화규소를 이용하여 만든 반도체 소자 중 특히 쇼트키 배리어 다이오드는 현재 가장 많이 사용되는 전력반도체 소자로써 스위칭 속도가 매우 빠르고 낮은 온저항 특성을 가지는 소자이다. 하지만 컨텍 엣지에서의 전계집중으로 인해 항복전압이 낮아지는 단점이 있다. 이를 해결하기 위해 다양한 엣지 터미네이션 기술이 제안되고 있는데, 본 논문에서는 최적의 항복전압을 갖기 위한 이중 필드 플레이트(Double Field Plate) 소자 구조를 제안하였다. 측정결과 제작한 소자는 온저항을 유지한 채 38% 향상된 항복전압을 나타내었다. 제안한 소자 특성 검증을 위해 소자를 설계 및 제작한 후 전기적 특성을 측정하였으며, 이중 필드 플레이트 구조는 길이와 두께가 서로 다른 필드 플레이트를 겹쳐 올림으로써 구현하였다.

• Journal of Korean Neurosurgical Society
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• 제55권1호
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• pp.12-17
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• 2014

Objective : Anterior cervical discectomy and fusion (ACDF) is often complicated by subsidence, pseudoarthrosis, kyphosis, and graft donor site morbidities. To decrease the occurrence of these complications, various types of cages have been developed. We designed this retrospective study to analyze and compare the efficacy and outcomes of ACDF using double cylindrical cages (DCC) (BK Medical, Seoul, Korea) versus an anterior cervical plating system with autogenous iliac crest grafts. Methods : Forty-eight patients were treated with autograft and plating (plate group), and 48 with DCC group from October 2007 to October 2011. We analyzed construct length, cervical lordotic curvarture, the thickness of the prevertebral soft tissue, segmental instability, and clinical outcomes. Results : There were no significant differences between the two groups with regard to the decrease in construct length or cervical lodortic curvature at the 3-, 6-, and 12-month follow-ups. The prevertebral soft tissue was thinner in the DCC group than the plate group immediately after surgery and at the 3-, 6-, and 12-month follow-ups. The difference in interspinous distance on flexion-extension was shorter in the plate group than the DCC group at the 3- and 6-month follow-ups. However, there was no significant difference in this distance between the two groups at the 12-month follow-up. Conclusion : A double cylindrical cage is a good alternative for fusion in patients with cervical degenerative diseases; the surgical method is relatively simple, allows good synostosis, has less associated prevertebral soft tissue swelling, and complications associated with autografting can be avoided.

• 한국해양공학회지
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• 제25권3호
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• pp.1-10
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• 2011

This paper estimates the residual longitudinal strength of a damaged double hull VLCC (Very Large Crude Carrier) under combined vertical and horizontal bending moments using Smith's method. The damage estimated in this study occurred due to collision or grounding accidents. The effects of the randomness of the yield stress, plate thickness, extent of damage, and the combination of these three parameters on the ultimate hull girder strength were investigated. Random variables were generated by a Monte Carlo simulation and applied to the double hull VLCC described by the ISSC (International Ship and Offshore Structures Congress) 2000 report.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.173-176
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• 2003

Progressive failure analysis of steel composite double T-beam is performed to investigate the mechanical effects of steel composite fabricated in the webs of double-T beam to replace concrete placing forms. The analysis is based on nonlinear finite element scheme considering material nonlinearities of concrete, reinforcing bar and PS steel. Four-parameter strength envelope defines the hardening and softening phenomena of concrete with consideration of the various levels of confining pressures. Rankine maximum strength criterion defines the elasto-plasticity of PS steel and reinforcing bar, and Von Mises $J_2$ failure criterion for steel plate which wraps the concrete webs of double T-beam. A 6m long two-span steel composite double T-beam is analyzed and compared with the experimental results.

• 한국정밀공학회지
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• 제21권2호
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• pp.195-202
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• 2004

This paper presents the fabrication and evaluation of mechanical behavior for a peristaltic micropump by flow simulation. The valve-less micropump using the diffuser/nozzle is consists of the lower plate, the middle plate, the upper plate and the tube that connects inlet and outlet of the pump. The lower plate includes the channel and the chamber, and the plain middle plate are made of glass and actuated by the piezoelectric translator. Channels and a chamber on the lower plate are fabricated on high processability silicon wafer by the DRIE(Deep Reactive Ion Etching) process. The upper plate does the roll of a pump cover and has inlet/outlet/electric holes. Three plates are laminated by the aligner and bonded by the anodic bonding process. Flow simulation is performed using error-reduced finite volume method (FVM). As results of the flow simulation and experiments, the single chamber pump has severe flow problems, such as a backflow and large fluctuation of a flow rate. It is proved that the double-chamber micropump proposed in this paper can reduce the drawback of the single-chamber one.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.284-290
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• 2012

Open reduction and anatomic reduction can create better function for the temporomandibular joint, compared with closed treatment in mandible fracture surgery. Therefore, the double miniplate fixation technique via mini-retromandibular incision was used in order to make the most stable fixation when performing subcondylar fracture surgery. Those approaches provide good visualization of the subcondyle from the posterior edge of the ramus, allow the surgeon to work perpendicularly to the fracture, and enable direct fracture management. Understanding the biomechanical load in the fixation of subcondylar fractures is also necessary in order to optimize fixation methods. Therefore, we measured the biomechanical loads of four different plate fixation techniques in the experimental model regarding mandibular subcondylar fractures. It was found that the loads measured in the two-plate fixation group with one dynamic compression plate (DCP) and one adaption plate showed the highest deformation and failure loads among the four fixation groups. The loads measured in the one DCP plate fixation group showed higher deformation and failure loads than the loads measured in the two adaption plate fixation group. Therefore, we conclude that the selection of the high profile plate (DCP) is also important in order to create a stable load in the subcondylar fracture.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.276-278
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• 2007

Many processes have been introduced to join PE pipes, but most of these methods have lots of disadvantages such as costs and lack of reliability, etc. Recently due to the benefits of cost, safety and reliability, the but welding has been paid much attention to join PE pipes. In case of butt welding, the heat plate which is used to melt PE pipes is the most critical equipment. In this study, after designed secondary developed heat plate of new shape, the PE double wall pipes were but-welding by using the developed heat plate and secondary developed heat plate and comparison of weld-zones and tensile test were performed. As results of tensile test, tensile strengths using secondary developed heat plate were measured higher $1.17{\sim}1.5$ than using developed heat plate.