• 보건행정학회지
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• 제8권1호
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• pp.1-14
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• 1998

Analysis of practice variations has been one of important issues in trying to contain costs as well as to manage quality in health care. This study was conducted to provide statistical model for analysing variations in inpatient costs by type of hospitals. Four K-DRGs including Cesarean section, appendectomy, cataract extraction, and pediatric pneumonia with CC class 0 were selected, and means and dispersions of inpatient procedure and operation costs were simultaneously compared between type of hospitals. The results indicated that joint modelling of means and dispersions by gamma distribution was a very useful analytic tool for identifying factors which might have relationship with variations in inpatient costs. This model can be expanded to test the significance of several independent variables in analysing cost variations. In surgical conditions, means and unit variations of procedure and operation costs showed consistent pattern which was tertiarty hospital, general hospital, and hospital in descending order. Different findings were identified in pediatric pneumonia, from which mean and unit variation of procedure and operation cost was the highest in general hospital. The practical implication of this difference could not be drawn from this study. It will be done by further sophisticated researches. In order to develop health policy for cost containment and quality management in Korea, it is essential to find out manageable factors affecting variations in practice patterns which include characteristics of population, providers, regions, and so on. The statistical model presented in this study will give health services researchers useful insights for future investigations in analysing cost variations.

• 대한토목학회논문집
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• 제33권6호
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• pp.2381-2391
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• 2013

일반적으로 에너지파일의 열적 성능에 영향을 주는 중요한 인자로 지반의 열 물성, 열 교환기 형태, 운용방법, 파일 간 열 간섭 등이 고려될 수 있다. 본 연구에서는 지반의 실제 조건을 반영한 수치모델을 통해 이들 인자들이 미치는 영향을 살펴보았다. 지반의 포화 정도에 따라서 파일의 열 교환율은 최대 3배까지 차이를 보였으며, 열 저항은 최대 8.7%의 차이가 발생하였다. 또한 열 교환기 유형이 파일의 열 성능에 영향을 주며, 3U-Type이 W나 U-Type에 비해 상대적으로 높은 열 효율을 보였다. 운용방법에 있어서, 부분가동 시(8시간 가동, 16시간 휴지) 연속가동에 비해서 약 20%의 열효율을 보전할 수 있으며, 장기적인 열 축적현상을 방지하는데 유리하다. 지반의 조건에 따라 군 말뚝에 의한 열 간섭 정도가 달라지는데, 지반이 포화상태에서 건조 상태로 갈수록 군 말뚝에 의한 열 간섭효과는 감소한다. 일반적인 지반조건에서 열 교환 감소율 1%미만을 유지하는 적정 이격 거리는 U-Type에서 최대 3.2D, W-Type에서 최대 3.6D, 3U-Type에서 최대 3.7D로 산정되었다.

• Journal of Biosystems Engineering
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• 제9권1호
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• pp.22-33
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• 1984

Husk separator is an indispensable equipment in rice milling plants. However, any basic research on the designing and operating criteria of the husk separator have rarely been conducted in Korea. According to the survey results reported recently, grain loss occurs in the process of rice husk separation at custom rice milling plants in Korea and the performance of husk separator has also not been identified. With this regard this study was conducted with a typical commercial husk separator to investigate the effect of the operational factors such as feed rate, blower speed and opening ratio on the velocity distribution in the air duct and the performance of the separator. The results are summerized as follows: 1. The average wind velocity in the primary air duct increased linearly with the blower rpm and the size of air inlet port in both cases of double type and single type operations. 2. The coefficient of variation in the horizontal wind velocities in the primary air duct was the minimum when the opening ratio was 0.22 ($0.052m^2$ of air inlet port) in both cases of single type and double type operations regardless of the blower speeds used in this test. The average wind velocity at the upper part of air duct was greater by 2-5 m/s than the velocity at the bottom part in double type operation. In case of single type operation, however, the average velocity in the middle part was greater than the upper or bottom part when the opening ratio was greater than 0.74. 3. The relationship between the overall effectiveness of separation(Ed for double type and Es for single type) and the average wind velocity (Va) in the primary air duct was expressed in the following quadratic functions. $$Ed=-190.84+106.18Va-10.052Va^2$$ ($r^2$ = 0.97782) $$Es=-223.76+106.23Va-9.1935Va^2$$ ($r^2$ = 0.97029) The average wind velocity required to obtain the overall effectiveness of separation more than 80% ranged from 4.04 m/sec to 5.84 m/sec in case of double type operation, and from 4.70 m/sec to 6.20 m/sec in case of single type. 4. An optimum wind velocity can be obtained with an increase in the blower speed or the size of air inlet port as presented in Figure 8. There was a tendency that the faster the blower speed, the narrower the control range of the air inlet port. 5. The feed rates (1850kg/hr and 2100kg/hr) adopted in this experiment did not bring about a significant difference in both the overall effectiveness of separation and the power consumption. 6. The energy consumption increased cubically with the blower speed but linearly with the size of the air inlet port. On the basis of the results described in items 1, 3, and 6, it would be more economic to adjust the size of the air inlet port larger with a relatively low blower speed than to adjust the size smaller with a relatively high speed.

• Journal of Korean Neurosurgical Society
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• 제30권4호
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• pp.501-508
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• 2001

Objectives : Hemifacial spasm is painless uncommon disorder characterized by involuntary paroxysmal movement on one side of face. It is known that hemifacial spasm is mainly due to pulsatile compression by vessels at the root exit zone(REZ) of the facial nerve. Microvascular decompression at REZ of the facial nerve has become the standard treatment modality for hemifacial spasm. The authors have analized patients with hemifacial spasm treated with microvascular decompression to evaluate operation result and clinical course after operation. Patients and Methods : From 1992 to 1999, 41 patients with hemifacial spasm underwent this operation. Retrospective analysis of operation results and clinical recovery patterns was done. The length of observation had been more than 6 months in all cases. Results : The ratio of male to female was 1:1.4, and age at operation ranged from 24 to 66 years. Their mean age was 47.6 years and the mean preoperative duration of symptoms was 7.2 years. Most common offending vessels were AICA in 18 cases(48%) and second most common were PICA in 13 cases(31.7%). The rest of them were 3 case in vertebral artery, and 7 cases(13%) in multiple offending vessels. Patterns of improvement after surgery could be divided into 4 clinical types. There was complete recovery in 3 days after operation in 24 cases(58.6%, Immediate complete recovery). There was complete recovery in 3 days after operation, and symptom was recurred partially, which was gradually subsided in 2 weeks after operation in 4 cases(9.8%, Delayed complete recovery type I). There was partial recovery after operation and symptom was compretely disappeared gradually in 6 months after operation in 7 cases(17.1%, Delayed complete recovery type II). Finally, there was partial recovery after operation, and symptom was somewhat remained after 6 months later(14.5%, Delayed partial recovery). Conclusion : In conclusion, microvascular decompression for hemifacial spasm is a safe and reliable treatment modality with good results of improvement and there are 4 recovery patterns in clinical course after operation in our series. Therefore, follow-up observation after microvascular decompression is necessary to evaluate the operative results and complication, especially in the delayed resolved cases.

• 한국산림과학회지
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• 제102권2호
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• pp.229-238
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• 2013

효율적인 임목수확작업 기술의 보급과 임목수확작업시스템을 구축하기 위해 타워야더 및 스윙야더 등에 의한 전목집재작업시스템과 굴삭기 그래플 등에 의한 단목집재작업시스템의 작업비용을 비교 분석하였다. 전목집재 작업시스템에서 작업비용을 산정한 결과, 체인톱에 의한 벌목작업비용이 2,099원/$m^3$, 타워야더에 의한 전목집재작업비용이 28,286원/$m^3$, 스윙야더에 의한 전목집재작업비용이 18,265원/$m^3$, 굴삭기 그래플 및 체인톱에 의한 조재작업비용이 18,939원/$m^3$, 바퀴식 미니포워더에 의한 소운재 및 집적 작업비용이 20,484원/$m^3$, 굴삭기 그래플 및 소형 운재차에 의한 소운재 및 집적 작업비용이 12,701원/$m^3$으로 나타났다. 또한, 단목집재작업시스템에서 작업비용을 산정한 결과, 체인톱에 의한 벌목 및 조재 작업비용이 10,160원/$m^3$, 굴삭기 그래플에 의한 단목집재작업비용이 7,567원/$m^3$, 굴삭기 그래플에 의한 지엽수집작업비용이 6,982원/$m^3$, 굴삭기 그래플에 의한 작업로개설비용이 3,040원/$m^3$, 바퀴식 미니포워더에 의한 소운재 및 집적 작업비용이 20,484원/$m^3$, 굴삭기 그래플 및 소형 운재차에 의한 소운재 및 집적작업비용이 12,701원/$m^3$으로 나타났다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.94-100
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• 1997

The purpose of this study is to investigate the effects of operation factors of a typical main spindle system on its efficiency. Among important factors, material type of ball-bearing, bearing-lubricant type and main spindle bearing preload are taken into considered.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.14-18
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• 1987

In this paper, a system program is introduced for the effective operation of revolute type robot manipulator. The I system program consists of several modes and specific functions. These modes and functions are flexible and easy to use because the structure is modular and conversational. This program had implemented and verified the efficiency together with a five axes robot.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.405-406
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• 2011

• 한국농공학회지
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• 제16권4호
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• pp.3600-3610
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• 1974

Experimental work of batch-type dryer was conducted to develop its optimurm operating conditions by analyzing the major factors which affect the drying performance. A laboratory batch-type dryer was constructed and tested for various levels of heated-air rates, and depths of grain deposit. Tong-il rice variety having the initial moisture content of approximaely 23 per cent in wet basis was used for the experiment. The criteria selected for establishing the optimum operating condition were the drying performance rate, the thermal efficiency, and the operational cost of the dryer. The results of the study are summarized as follows: 1. The performance rate of dryer for a specific operating condition was defined as total amount of material dried per hour when the moisture content of grains in the upperlayer reaches to 16 per cent in wet basis. The optimum operating conditions as viewed in the rate of drying performance could be justified by functional realtionship between the depth of grain deposit and air flow rate. In other words, there was a definite depth of grain deposit for a given air-rate which make the dryer performance maximum. The optimum grain depth for the batch-type dryer with 3.3㎡ loading area and with the attached axial fan was about 35cm. 2. The thermal efficiency for the dryer was evaluated by the ratio of the latent heat required to evaporate the grain moisture to the heat input required to raise the ambient air-temperature to 40 degree centigrade. The optimum operating condition as viewed in term of thermal efficiency analyzed was that grater depth and lower air flow-rate may be desirable. This condition is contracted with the optimum condition as viewed by the dryer performance rate. 3. The annual operating cost of batch-type dryer was analyzed for different annual hour of use and for different operation condition. The optimum condition as viewed in terms of operating cost was almost identical to one as viewed in terms of dryer performance rate. Therefore, the most economical use of batch-type dryer for the same annual operating hours can be obtained when the dryer operated in the condition of maximum dryer performance rate. Increasing the annual operating hour may be desirable to cut down the dryer operation cost, since the annual hour of dryer use is much sensitive to the operating cost than any peractical conditions of dryer operation. 4. The most desirable operational condition as justified by combining all the criteria, dryer performance rate, thermal efficiency and annual operating cost, could be concluded to operate the dryer in the condition of maximum performance rate. The condition in general is identical to the lowest operation cost for a given annual operating hour.

• 대한전자공학회논문지
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• 제25권5호
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• pp.528-535
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• 1988

This paper presents a constructing theory of variable arithmetic operation systems for computing multiplications and multiplicative inverse in GF(2**m) based on a modulo operation of degree on elements in Galois fields. The proposed multiplier is composed of a zero element control part, input element conversion part, inversion circuit, and output element conversion part. These systems can reduce reasonable circuit areas due to the common use of input/output element converison parts, and the PLA and module structure provice a variable property capable of convertible uses as arithmetic operation systems over different finite fields. This type of designs gives simple, regular, expandable, and concurrent properties suitable for VLSI implementation. Expecially, the multiplicative inverse circuit proposed here is expected to offer a characteristics of the high operation speed than conventional method.