• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1303-1309
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• 2003

This paper presents the static and dynamic measurements for the strength and motion characteristics as well as the improved procedures to assess strength of wheel loaders. Two scenarios for static measurement were decided by which cylinder was actuating. The dynamic measurement was performed for two types of motion, that is, simple reciprocation of the working devices and actual working motion including traveling, digging and dumping. The measured items were stresses, cylinder pressures and strokes. Stress induced by bucket working showed higher level than that by boom working. The measured cylinder speeds were relatively superior to the design speeds. Working stress histories were thought to be closer to static rather than dynamic. A fully assembled FE model was prepared for structural analysis. In this paper, a more simple method was suggested to avoid nonlinearity caused by heave of rear frame under digging forces. Also how brake affected on structural behavior and digging force was examined closely in relation with tire pressure. It was confirmed that the overall stress level of wheel loader during turning traveling with loaded bucket was far lower than the yield stress of material.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.51-55
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• 2009

Purpose: Excessive apocrine gland secretion and bacterial decomposition cause axillary osmidrosis, which results in physical discomforts and social problems of patients. Many surgical procedures have been introduced such as skin excision and simple closure, local flap, skin graft, subcutaneous shaving and liposuction method, but the result was not satisfactory to patients and several complications, such as symptom recurrence, hematoma, seroma, delayed wound healing, skin flap necrosis and scarring remain as problems. Methods: For the purpose of reducing these problems, we employed combination treatment of liposuction and rasping method. From January 2006 to February 2008, Total 54 patients were treated with this procedure for bilateral axillary osmidrosis. Results: Follow - up evaluation period was from 2 months to 12 months, and the results were satisfactory. In our method, the length of skin incision is less than 1 cm, so the resultant scar is negligible. Apocrine glands in subcutaneous tissue were mostly removed by liposuction apparatus and remained other glands in subdermal area were mostly removed by rasping. The recurrence rate and postoperative complication were minimal. Conclusion: Our method is very simple, short operation time and excellent results without specific complication.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.763-766
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• 2005

The restoration of the fingernail is not simple in case of amputated distal fingertip which involved the pulp and nail. The nail should maintain a length of at least 2 mm from the eponychium for an adequate grip and decent appearance. Various methods to reconstruct the fingernail bed are available. The nail bed graft from amputated finger or great toe, and free onychocutaneous flap are commonly used. The nail bed of the injured tip tends to be atrophied, deformed and failed as a graft. And the great toe is often turned down as a donor. We have restored satisfactorily the nail beds of three injured finger tips with eponychial cutaneous flaps. The pulps were reconstructed with either a reverse dorsal digital island flap or free pulp graft. Repeated again. A mean follow- up was six months. The nail grew up to the average of 3.7 mm. All patients were satisfied with the length of the nail and met with good cosmetic results. An eponychial cutaneous flap is useful to restore the nail of the distal fingertip amputation. The procedure is relatively simple and morbidity is minimum.

• 대한의용생체공학회:의공학회지
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• 제26권3호
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• pp.129-132
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• 2005

It is one of the most important issues to determine a target brain image that gives a common coordinate system for a constructing population-based brain atlas. The purpose of this study is to provide a simple and reliable procedure that determines the target brain image among the group based on the inherent structural information of three-dimensional magnetic resonance (MR) images. It uses only 11 lines defined automatically as a feature vector representing structural variations based on the Talairach coordinate system. Average characteristic vector of the group and the difference vectors of each one from the average vector were obtained. Finally, the individual data that had the minimum difference vector was determined as the target. We determined the target brain image by both our algorithm and conventional visual inspection for 20 healthy young volunteers. Eighteen fiducial points were marked independently for each data to evaluate the similarity. Target brain image obtained by our algorithm showed the best result, and the visual inspection determined the second one. We concluded that our method could be used to determine an appropriate target brain image in constructing brain atlases such as disease-specific ones.

• 대한미생물학회지
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• 제19권1호
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• pp.79-83
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• 1984

To determine the existence of anti-HLA antibodies finally in 220 human placental extracts to be proved negative antiserum by previous anti-HLA A,B,C antibody screening procedure, the present study was performed by fractionation of immunoglobulins using saturated ammonium sulfate and by simple batch method on DEAE cellulose. Thereafter using known 150 T-lymphocyte panels, complement-dependent microlymphocytotoxicity test was performed to observe the existence of anti-HLA antibodies and the degree of the antibody response of the concentrates. The following results were obtained: 1. Of total 141 placental sera concentrated 45 cases(31.9%) were showed significant anti-HLA A,B,C antibody response after concentration(Excellent, 19(13.5%), Good, 3(2.1%), Weak, 23(16.3%)). 2. Anti-HLA specificities of placental sera obtained after concentration were A2, A24, B13, B27, B44, B51, CN1, C7. 3. A new type C new-1 anti-HLA antibody that is only expressed in Korean people, was obtained. 4. 79 placental sera purrified by simple batch method using DEAE cellulose were showed negative anti-HLA antibody responses.

• 한국통신학회논문지
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• 제34권9B호
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• pp.892-899
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• 2009

주파수 분할 재사용 기법은 셀룰러 시스템의 성능을 향상시키기 위한 기술이다. 주파수 분할 재사용 기반시스템에 대한 기존 연구에서는 호의 발생과 채널 선택 과정을 설명하고 있지 않다. 따라서 본 논문에서는 단말의 채널 선택 과정을 설명하고 주파수 분할 재사용 기반 시스템의 성능을 분석한다. 성능은 채널 사용률과 호 차단 확률로 나타낸다. 본 논문의 결과는 차후 주파수 분할 재사용 기반 시스템의 성능 분석에 추가되어 실제적인 시스템의 성능 분석을 가능하게 할 것이다.

• Journal of Oral Medicine and Pain
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• 제17권1호
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• pp.19-29
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• 1992

Fear at the dental treatment is a problem not only for patient but for dentist as well, because the anxious patient often require more item, even for simple procedures. The anxiety level in response to dental procedures was evaluated through a simple questionnaire, Corahs, DAS. 783 female and 790 male outpatients were studied at the Dept. of Oral Diagnosis, PNUH from 1988 to 1989. The obtained results were as follows : 1. The anxiety level in female was significantly higher than that in male, and patients in 10s and 30s showed more anxious than those in other groups. 2. Housewives and pupils revealed higher level of anxiety. 3. The anxiety level in 524 (ICD) was the highest in all diseases, inspite of no difference among various diseases. 4. There was significantly higher level of anxiety in the patient of Orthodontics and Pedodontics than those of other departments. 5. There was no difference in anxiety level between acute and chronic group. 6. Dental phobes were more in female than in male.

• Geomechanics and Engineering
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• 제1권3호
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• pp.193-204
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• 2009

A 10.4-m high highway embankment retained behind mechanically stabilized earth (MSE) walls is under construction in the northeastern part of the Indian state of Bihar. The structure is constructed with compacted, micaceous, grey, silty sand, reinforced with polyester (PET) geogrids, and faced with reinforced cement concrete fascia panels. The connections between the fascia panels and the geogrids failed on several occasions during the monsoon seasons of 2007 and 2008 following episodes of heavy rainfall, when the embankment was still under construction. However, during these incidents the MSE embankment itself remained by and large stable and the collateral damages were minimal. The observational data during these incidents presented an opportunity to develop and calibrate a simple procedure for estimating rainfall induced pore water pressure development within MSE embankments constructed with backfill materials that do not allow unimpeded seepage. A simple analytical finite element model was developed for the purpose. The modeling results were found to agree with the observational and meteorological records from the site. These results also indicated that the threshold rainwater infiltration flux needed for the development of pore water pressure within an MSE embankment is a monotonically increasing function of the hydraulic conductivity of backfill. Specifically for the MSE embankment upon which this study is based, the analytical results indicated that the instabilities could have been avoided by having in place a chimney drain immediately behind the fascia panels.

• 대한산업공학회지
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• 제17권2호
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• pp.131-142
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• 1991

The concept of criterion function is proposed as a framework for comparing the geometric and computational characteristics of various nonlinear programming approaches to linear programming such as the method of centers, Karmakar's algorithm and the gravitational method. Also, we discuss various computational issues involved in obtaining an efficient parallel implementation of these methods. Clearly, the most time consuming part in solving a linear programming problem is the direction finding procedure, where we obtain an improving direction. In most cases, finding an improving direction is equivalent to solving a simple optimization problem defined at the current feasible solution. Again, this simple optimization problem can be seen as a least squares problem, and the computational effort in solving the least squares problem is, in fact, same as the effort as in solving a system of linear equations. Hence, getting a solution to a system of linear equations fast is very important in solving a linear programming problem efficiently. For solving system of linear equations on parallel computing machines, an iterative method seems more adequate than direct methods. Therefore, we propose one possible strategy for getting an efficient parallel implementation of an iterative method for solving a system of equations and present the summary of computational experiment performed on transputer based parallel computing board installed on IBM PC.

• 전력전자학회논문지
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• 제3권1호
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• pp.53-60
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• 1998

본 논문은 비디오 카메라 및 프로젝션 TV 등 영상 기기의 요소 부품인 캠코더용 Iris Assembly에 있어서 동작원리, 구성부품의 특성, 동작특성 해석과 각 요소부품의 개발시 중요 Know-how 등을 언급한다. 저전력용으로 소형이지만 간단한 구조로 만들기 위한 자계회로를 실현하였다. 특히 잔류 자계의 영향과 동작 시간의 관계를 실험적으로 규명한다. 소형 정밀부품의 국산화 개발에 있어서 필요한, 간편한 구동 시스템 원리와 그로 인해 발생하는 비선형성 토오크의 문제점 및 개발 공정 등을 설명하고, 각 부품의 Burr 최소화를 위한 점검 요소, 소형 요소 부품의 공정 등을 다룬다.