• Journal of Periodontal and Implant Science
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• 제39권3호
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• pp.321-329
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• 2009

Purpose: The purpose of this study was to evaluate the bone regeneration of particulated hydroxyapatite(HA) and block type of hydroxyapatite graft in rabbit calvarial defects. Methods: An 8 mm calvarial circular defects were created in sixteen young adult New Zealand white male rabbits (weight $3.0{\sim}3.5kg$). Each defects were filled with Bio-Oss, particulated HA and block type HA. Sham surgery control defects were filled with blood clots. The specimens were harvested at 4 weeks and 8 weeks for histologic and histomorphometric evaluation. Results: Histomorphometric analysis demonstrated statistical differences in defect closure, new bone formation, and bone density of the four groups. Block type of HA group showed increased bone formation and bone density at 4 weeks and 8 weeks compared with Bio-Oss group or sham surgery control group(p<0.05). Conclusions: Block type of HA is an effective material for osteoconduction in rabbit calvarial defects, which may acts as a guide in use of these products in human application.

• The Korean Journal of Pain
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• 제13권1호
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• pp.93-96
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• 2000

Background: Psoas compartment block with local anesthetics and corticosteroids is one of the treatments which provides long term analgesia of the lower back and anterior thigh unilaterally, and its technical easiness and safety allows blind application without C-arm guidance in the out-patient clinic. This study aimed to evaluate the mean of the depth from the skin to the psoas compartment, and its correlation to the following attributes: age, weight, height and PI (Ponderal Index). Methods: We investigated 28 patients who underwent psoas compartment block. All blocks were performed using Chayen's method (punctured at the point of 3 cm caudally and 5 cm laterally from the 4th lumbar vertebral spinous process) with a 22 G, 8 cm Tuohy needle under C-arm guidance. We recorded the depth from skin to the psoas compartment, height, weight and PI (weight (kg)/height (cm)$\times100$ (%)). Data were analyzed using the Pearson product-moment correlation coefficients. The correlations between the depth and other attributes identified by p-value of less than 0.05 were considered statistically significant. Results: The mean depths from skin to the psoas compartment were $6.02{\pm}0.28$ cm in men, $5.44{\pm}0.22$ cm in women. There is no significant correlation between the depth and other patient's attributes. Conclusions: The mean depths from skin to the psoas compartment may be one of the guide for psoas compartment block in outpatient clinics without C-arm guidance.

• 화약ㆍ발파
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• 제37권2호
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• pp.14-21
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• 2019

개별요소법은 절리가 발달한 불연속 암반의 모델링에 매우 유력한 수치해석적 방법이다. 또한 발파 후 큰 변위가 일어나는 단계에서의 모델링에도 효과적이다. 개별요소법에서 각 요소는 강체로 가정하고, 요소 간 약간의 중첩을 허용하여 접촉 변위로부터 상호 작용력을 계산한다. 개별요소의 경계로 정의되는 절리의 강성은 블록요소 상호 간의 거동을 결정하는 중요한 변수로서 변형의 크기와 파괴 양상에 영향을 준다. 그러나 요소 간 과도한 중첩으로 인한 수치해석적 불안정성을 방지하기 위해서 어떤 준정적인 문제에 있어서는 실제 절리 물성과 관계없이 임의로 선정된 절리 강성 값이 사용되기도 한다. 해석의 주된 관심사가 정밀도 높은 변형의 크기 예측이냐, 불연속체의 파괴 양상이나 파괴 후 파괴된 블록들의 거동 예측이냐에 따라, 절리 강성에 대한 입력 자료 값은 결과에 큰 영향을 주지 않을 수도 있고, 심각한 예측 오류를 가져올 수도 있다. 본 연구는 개별요소법을 이용한 수치해석 모델링에서 절리 강성 값이 해석 결과에 미치는 영향을 이해하고 입력자료 선정 지침에 도움을 주고자 수행되었다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제26권2호
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• pp.19-30
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• 2020

Purpose: The ratio of the visually impaired is gradually increasing due to various causes such as natural aging, accidents, and environmental changes. Therefore, this study has two folds. Firstly, it aims to analyze the current satisfaction level with information facilities for the visually impaired. Secondly, it aims to examine the factors affecting the satisfaction with indoor information facilities. Through this study, it helps to identify problems of information facilities for the visually impaired and it works as a practical data for further improvements. Methods: For 50 visually impaired people, a telephone survey was conducted on the satisfaction with the braille blocks, braille signboards, braille information boards with tactile map, audio guide devices, and safety egress devices. Microsoft Excel and SPSS 26.0 were used for the analysis. Results: It was confirmed that the overall satisfaction with the indoor information facilities was very low. The more the visually impaired people recognized the installation standards, and the better the maintenance was, the higher the satisfaction. In the case of braille blocks and braille signboards, the effect of information transfer on satisfaction was relatively high. In the case of audio guide device and safety egress device, the standard suitability influenced satisfaction. Implications: The low level of satisfaction with the overall information facilities can impede visually impaired people from receiving practical help through the information facilities. Factors influencing the satisfaction level of each facility were identified, which makes it possible to prepare effective improvement measures.

• 한국시뮬레이션학회논문지
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• 제17권3호
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• pp.85-94
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• 2008

본 연구는 컨테이너 터미널에서 사용될 수 있는 교착방지를 위한 알고리즘 개발을 목표로 하였다. 기존의 교착방지 알고리즘은 많은 계산시간을 소요한다는 단점을 극복하기 위하여 본 연구에서는 하나의 경로에 대해서 예약스케줄을 작성하여 두고 반복적으로 사용하는 예약 스케줄 표 방식을 제안하였다. 시뮬레이션 실험 결과 예약 스케줄 표 방식은 그때그때의 주행경로에 대한 예약스케줄링을 위하여 계산시간이 필요 없기 때문에 AGV의 실시간 운영을 위하여 유용한 방식임을 알 수 있었다.

• The Korean Journal of Pain
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• 제9권1호
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• pp.210-214
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• 1996

Thoracic sympathetic ganglion block(TSGB) with alcohol is a traditional method for treating a variety of disease at pain clinics. But it is a difficult block to perform requiring both skill and experience. Therefore, we performed a thoracic endoscopic cauterization to evaluate the efficacy of this method. A patient suffering sever forearm and hand pain due to radius fracture of the right arm, one and half years earlier, was referred to several different orthopaedic department of various hospitals with continued aggravated symptoms. He was then admitted to our hospital's orthopaedic department. Our diagnosis, confirmed by thermography, revealed reflex sympathetic dystrophy. Patients was therefore referred to the pain clinic where treatment consisted of endoscopic thoracic sympathetic cauterization under general anesthesia. Patient was intubated with Robertashow 37 Fr. double lumen tube left sided. Left lateral and slight head up position was applied to make lesion side up. Incisions were made to penetrate trocas 5 mm diamether on 4 th intercostal space along mid axillary line and midclavicular line. Negative pressure suction on ipsilateral lung and CO2 insufflation under 10 mmHg was applied to reduce lung size. Cauterization on thoracic sympathetic chain at T3 level was done under endoscoic guide. 24 Fr. chest tube was inserted. Patient's symptoms cleared and he was satisfied with the results of this treatment.

• The Korean Journal of Pain
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• 제19권1호
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• pp.68-71
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• 2006

Background: Stellate ganglion block (SGB) is a selective sympathetic blockade that affects the head, neck and the upper extremities. It is an important method that has been frequently used in pain clinics due to its wide range of indications. But there were some problem with performing SGB at C6 or C7. Thus, various techniques have been recently introduced to successfully perform SGB; among them, there is the oblique approach. This study was performed to evaluate the effectiveness of the oblique approach for performing SGB in C7. Methods: Forty six patients with sudden hearing loss were studied. In group I, the patient underwent C7 oblique SGB with 1% mepivacaine (3 ml) under fluoroscopic guidance. In group II, the patients underwent the C7 classical anterior approach SGB with 1% mepivaine (5 ml) under fluoroscopic guidance. We compared the occurrence of Horner's syndrome, the side effects and the changes of temperature of the skin of the hand. Results: The rate of Horner's syndrome was 81.5% in the group I and 84.2% in the group II. The rate of incurring increased skin temperature (${\geq}34^{\circ}C$) of the fingers was 77.7% and 79.4% in each group, respectively. Conclusions: The C7 oblique approach for SGB showed the same SGB effect compared with the C7 anterior approach for SGB, and there were also fewer complications. We conclude that C7 oblique SGB may be a beneficial method for treating patients with this particular malady.

• Geomechanics and Engineering
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• 제12권4호
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• pp.723-738
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• 2017

Rock is a heterogeneous material, which introduces complexity in the analysis of rock slopes, since both the existing discontinuities within the rock mass and the intact rock contribute to the degradation of strength. Rock failure is often catastrophic due to the brittle nature of the material, involving the sliding along structural planes and the fracturing of rock bridge. This paper proposes an advanced discretization method of rock mass based on block theory. An in-house software, GeoSMA-3D, has been developed to generate the discrete fracture network (DFN) model, considering both measured and artificial joints. Measured joints are obtained from the photogrammetry analysis on the excavation face. Statistical tools then facilitate to derive artificial joints within the rock mass. Key blocks are searched to provide guidance on potential reinforcement measures. The discretized blocky system is subsequently implemented into a discontinuous deformation analysis (DDA) code. Strength reduction technique is employed to analyze the stability of the slope, where the factor of safety can be obtained once excessive deformation of slope profile is observed. The combined analysis approach also provides the failure mode, which can be used to guide the choice of strengthening strategy if needed. Finally, an illustrated example is presented for the analysis of a rock slope of 20 m height inclined at $60^{\circ}$ using combined GeoSMA-3D and DDA calculation.

• 대한치과보철학회지
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• 제34권4호
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• pp.746-754
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• 1996

개교증, 절연부 파절, 변색등 심미적 요인으로 라미네이트를 설측연장시 연장길이에 따른 파절강도를 알아보기위해 발거된 60개의 상악 전치의 순면에 3개의 seating form을 형성하고sheet wax를 사용하여 가로 5mm $^*$세로 5mm $^*$두께 0.9mm의 block을 형성하고, 각 군에 따라 I군 : 0.5mm, II군 : 1mm, III군 : 2mm, IV군 : 0mm로 설측 연장 길이를 달리하여 block을 형성 이를 인상채득하여 내화모형을 제작하였다. 여기에 라미네이트용 도재를 2회에 걸쳐 축성 통법대로 소성 제작하였다. block에 맞추어 contouring하고, 내화매몰재를 제거 sandblast처리를 시행하였다. 그후 레진시멘트로 합착하였다. 절치간 각도를 127도로 특별히 제작된 holding device를 이용하여 인스트론 만능시험기에 시편을 거상하고, 분당 0.5mm cross head speed로 파절강도를 측정하여 다음과 같은 결과를 얻었다. 1. 각 군의 평균파절강도는 대조군인 설면으로 연장치 않은 IV군에서 86.95Mpa, 0.5mm 연장한 I군에서 44.98Mpa, 1.0mm연장한 II군에서 27.47Mpa, 2.0mm연장한 III군에서 19.61Mpa의 순으로 나타났다. 2. 모든 실험군 사이에는 통계적으로 유의성 있는 차이를 나타냈고(p<0.01), 이러한 실험 결과로 미루어 보아 라미네이트 디자인시, 설면으로 연장치 않거나, 절연부의 피개가 불가피한 경우에는 설면으로 0.5mm 연장하는 것이 파절 강도면에서 유리하다고 사료된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.635-636
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• 2012

In the present work, investigations by high frequency resonance technique for diagnosis of defect frequencies of linear motion unit are reported. Raw vibration signature of the moving parts at different speeds of operation has been demodulated. Envelope detected spectrum is analyzed to evaluate various defect frequencies and their energy levels. Experimentally evaluated frequencies are compared with theoretically determined defect frequencies. These frequency values and their energy levels are used to monitor intrinsic condition of linear motion unit as well as to establish severity of existing/developed defects on the LM guide and inside the LM block. Relative comparisons of linear motion units of the same type are made at various operating speeds under identical conditions of operation on the basis of identified defect frequencies and severity of defects.