• 한국지반공학회논문집
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• 제21권8호
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• pp.73-84
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• 2005

본 논문에서는 피에조콘 관입시험 결과와 상재하중으로부터 점토의 비배수전단강도를 간단히 예측하기 위한 피에조콘 인공신경망 모델 구축에 대하여 기술하였다. 피에조콘 인공신경망 모델의 구축을 위하여 먼저 국내 8개 지역에서 수행된 피에조콘 관입시험 결과와 불교란 시료에 대해 수행된 비압밀-비배수 삼축압축실험(UU)으로 얻어진 비배수전단강도 결과를 바탕으로 데이터베이스가 구축되었으며 오차역전파 알고리즘에 의하여 다층 구조를 갖는 최적 인공신경망 모델이 구성되었다. 구성된 인공신경망 모델은 모델 구축 시에 사용되지 않은 새로운 검증자료에 대해 비배수전단강도 예측을 수행하고 실내시험 결과와 비교함으로써 모델의 타당성이 검증되었다. 또한 피에조콘으로부터 비배수 전단강도의 예측을 위해 제안된 기존의 경험적 방법으로 예측된 비배수전단강도와 제안된 모델의 예측결과를 비교하였다. 인공신경망 모델들은 사용된 전달함수에 따라 단일 은닉층 내에 존재하는 최적 뉴우런 개수는 다르지만 학습자료와 검증자료에 대해 공통적으로 결정계수 $R^2=0.69\~0.72$ 범위의 예측정확도를 보여 국내 연약지반에서 피에조콘 관측결과들과 비배수전단강도 간의 비선형적 상관관계를 정의하는 데에 유용함을 알 수 있었다. 또한 구성된 인공신경망 모델은 지역적인 조정(site calibration)을 필요로 하는 기존의 경험적 방법들에 비하여 전 지역에서 고르게 예측신뢰성이 높으며 이는 학습과정을 통하여 각 지역의 지반공학적 특성을 일반화하는 데에 성공했기 때문으로 인공신경망 모델이 국내 전 지역에서 적용될 수 있는 일반화된 모델로 발전할 수 있음을 의미한다.

• Archives of Plastic Surgery
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• 제36권5호
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• pp.583-590
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• 2009

Purpose: In the cases of a vascular compromised condition in an injured lower extremity, soft tissue coverage with free tissue transfer presents a challenging problem to the reconstructive surgeon. For this reason, cross - leg flaps are still used in unusual circumstances. Advances in surgical technique has made the cross - leg free flap possible although it may require long operation time along with significant donor site morbidity. Therefore, a pedicled cross - leg muscle flap may be an alternative treatment modality when local flap or free flap is not possible. Methods: Twelve patients(9 males and 3 females) underwent the operation between October of 2001 and December of 2008. The patients' age ranged from 6 to 82 years. The unusual defects included the regions such as the knee, popliteal fossa, distal third of the tibia, dorsal foot, and the heel. Indications for the cross - leg gastrocnemius flap are inadequate recipient vessels for free flap(in eight cases), extensive soft tissue injuries(in three cases) and free flap failure(in one case). The muscle flap was elevated from contralateral leg and transferred to the soft tissue defect on the lower leg while both legs were immobilized with two connected external fixator systems. Delay procedure was performed 2 weeks postoperatively, and detachment was done after the establishment of the adequate circulation. The average period from the initial flap surgery to detachment was 32 days (3 to 6 weeks). Mean follow - up period was 4 years. Results: Stable coverage was achieved in all twelve patients without any flap complications. Donor site had minimal scarring without any functional and cosmetic problems. No severe complications such as deep vein thrombosis or flap necrosis were noted although mild to moderate contracture of the knee and ankle joint developed due to external fixation requiring 3 to 4 weeks of physical treatment. All patients were able to walk without crutches 3 months postoperatively. Conclusion: Although pedicled cross - leg flaps may not substitute free flap surgery, it may be an alternative method of treatment when free flap is not feasible. Using this modification of the gastrocnemius flap we managed to close successfully soft tissue defects in twelve patients without using free tissue transfers.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.147-148
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• 2002

This study made use of four kinds of mating balls that were made with stainless steel but subjected to different annealing conditions in order to achieve different levels of hardness. In all load conditions, testing results demonstrated that the harder the mating materials, the lower the friction coefficient was. Conversely, the high friction coefficient found in soft martensite balls appeared to be caused by the larger contact area between the DLC film and the ball. Raman Spectra analysis showed that the transferred materials were a kind of graphite and that the contact surface of the DLC film seemed to undergo a phase transition from carbon to graphite during the high friction process.

• 천문학회지
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• 제27권1호
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• pp.45-53
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• 1994

We present the calculation of X -ray spectra produced through Compton scattering of soft X-rays by hot electrons in the spherical shell geometry, using fully relativistic Monte Carlo simulation. With this model, we show that the power-law component, which has been observed in the low luminosity state of low-mass X-ray binaries (LMXBs), is explained physically. From a spectral. analysis, we find that spectral hardness is mainly due to the relative contribution of scattered component. In addition, we see that Wi en spectral features appear when the plasma is optically thick, especially in the high energy range, $E{\gtrsim}100keV$. We suggest that after a number of scattering the escape probability approaches an asymptotic form depending on the geometry of the scattering medium rather than on the initial photon spectrum.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.115-118
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• 1998

ATM(Asynchronous Transfer Mode)을 기반으로한 BSC(Base Station Controller)를 이용한 무선 이동통신망에서는 크게 MSC, BSC, BTS로 구성 되어진다. BSC는 MSC(Mobile Switch Center)와의 STM-1급 (155.52Mbps) 정합이 이루어지며, 여러 BTS(Base Transceiver Subsystem)와 T1(1.544Mbps)/E1(2.048Mbps)급 정합이 이루어져 호연결, 관리, 제어 및 MT(Mobile Terminal)의 soft-handoff를 담당한다. BSC내의 저속 가입자 I/F에서는 BTS와 BSC내의 ATM switch와의 정합을 수행하면서 VPI/VCI변환, BSC 내부 cell format으로 변환, 그리고 UPC(Usage Parameter Control)등이 이루어진다. 본 논문에서는 ATM switch를 이용한 BSC 내부의 저속 가입자 I/F의 구현에 관해서 살펴본다.

• 대한미세수술학회:학술대회논문집
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• 대한미세수술학회 1992년도 제12차 학술대회
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• pp.66-66
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• 1992

• Archives of Reconstructive Microsurgery
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• 제9권2호
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• pp.154-157
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• 2000

Author report a case of double metatarso-phalangeal joint transplantation to the elbow joint in the 31 years old female patient who have large bone defect associated with skin and soft tissue defect. The donor joints were second and third metatarso-phalangeal joint as double joint transfer fashion to enhance stability of graft. The graft based on dorsalis pedis vessel to anastomosed with radial artery of recipient site. The result is unsatisfactory because of long lasting lateral instability of reconstructed elbow joint in spite of 40 degree flexion motion and fair axial stability. We can conclude that joints from foot can not be an effective donor for biologic joint arthroplasty of elbow joint even though double metatarso-phalangeal joint were harvested.

• Clinics in Shoulder and Elbow
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• 제17권3호
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• pp.145-150
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• 2014

In the patients of retracted massive rotator cuff tears, there are much of difficulty to functional recovery and pain relief. Nevertheless the development of treatment, there are still debates of the best treatments in the massive rotator cuff tears. Recenlty various of treatments are introduced; these are acromioplasty with debridement, biceps tenotomy, great tuberoplasty with biceps tenotomy, partial repair, mini-open rotator cuff repair, arthroscopic rotator cuff repair, soft tissue augmentation, tendon transfer, flap, hemiarthroplasty, and reverse total shoulder arthroplasty. That there is no difference of result for reverse total shoulder arthroplasty between patients who have massive rotator cuff tear without arthritis and patients who have cuff tear arthropathy. Reverse total shoulder arthroplasty is one of reliable and successful treatment options for massive rotator cuff tear. Especially it is more effective for patients who have a pseudoparalysis.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.489-498
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• 2005

In this study, the shaft resistance of drilled shafts socketed into weathered-and soft-rocks was examined by the constant normal stiffness(CNS) test. Large scale model tests were performed for different unconfined compressive strength, socket roughness, initial normal stress, and normal stiffness for identifying shear load transfer characteristics. Through comparisons with previous studies, it is found that the results by the present approach is good agreement with the general trend observed by existing empirical and analytical results.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2001년도 가을 학술발표논문집 Vol.28 No.2 (3)
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• pp.328-330
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• 2001

본 논문에서는 가정용 PC상에서 별도의 장치 없이 구축할 수 있는 다중 이미지 전송 시스템을 구현한다. 구현한 시스템은 한 대의 PC에서 여러 대의 카메라를 사용하여 이미지를 캡춰하는 장점이 있다. 또한 PC에서도 많은 부하를 주지 않아 시스템의 안정성을 보장한다. 네트워크의 상황에 따라 적절하게 대처함으로써, 영상의 전송율을 일정하게 유지한다. 정지 영상을 이용한 시스템이지만, 동영상의 경우와 거의 차이가 없다. 본 논문의 보안시스템은 간단한 구조와 저렴한 비용으로 인해, 일반인도 쉽게 구축할 수 있다. 산업재해감시, 상가의 도난방지, 유치원의 아동관찰 등의 여러 용도로 쓰일 수 있다.