• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.73-77
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• 1992

환봉소재의 정밀절단을 위한 고속 환봉절단 공정에 있어서 절단금형은 공정중 막대한 타격력을 받기 때문에 금형의 파손방지 및 내구성향상을 위한 금형설계 기술이 절실히 요구되고 있다. 이같은 절단금형의 최적설계를 위해선 타격시 램이 금형에 가하는 충격력에 대한 예측이 필수적이므로 본 연구에서는 환봉절단 공정에 대한 동역학적 해석을 통해 충격력과 접촉시간을 이론적으로 구하였으며 이를 기존의 이론값과 비교한 결과, 보다 정확한 충격력의 예측이 가능하였다. 그리고 본 이론을 국내 최초로 개발된 환봉절단 장치에 적용하여 타격속도, 절단저항, 램과 금형의 하중비 등의 인자들과 충격력 사이의 관계를 밝혀냄으로써, 향후 최적금형 설계를 위한 데이터 베이스를 구축하였다.

• The Monthly Diabetes
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• s.289
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• pp.19-25
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• 2013

당뇨병은 비외상성 하지 절단의 가장 중요한 원인 질환이다. 당뇨병성 족부병변은 당뇨병 환자의 발에 발생하는 모든 문제를 포괄적으로 의미하고 보행 장애나 하지절단을 가져오는 중한 합병증에 속하며 족부병변의 발생률은 당뇨병성 만성합병증에 대한 지속적인 교육과 관리를 통해 점차 감소추세이지만 5.3~10.5% 정도로 아직도 적지 않게 보고되고 있다.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.118-126
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• 2005

Abrasive waterjet (AWJ) cutting is an emerging technology for precision cutting of difficult-to-machining materials with the distinct advantages of no thermal effect, high machinability, high flexibility and small cutting forces. This paper investigated theoretical and experimental cutting characteristics associated with abrasive waterjet cutting of quartz GE214. It is shown that the proper variations of several cutting parameters such as waterjet cutting pressure, cutting speed and cutting depth improve the roughness on workpiece surfaces produced by AWJ cutting. From the experimental results by AWJ cutting of quartz GE214, the optimal cutting conditions to improve the surface roughness and precision were proposed and discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.367-371
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• 2010

가뭄 발생원인은 기후학적인 인자(온도, 바람, 상대습도 등)들과 밀접한 관계를 갖고 있으나, 가장 큰 원인은 강수부족이라고 말할 수 있다. 따라서 가뭄은 정상수준 이하의 강수 상황이 연속적으로 발생하여 나타나며, 설정된 절단수준에 대해 가뭄의 지속기간, 심도, 발생간격 등을 정의한 후 이에 대한 시계열 분석을 수행하여 가뭄의 특성을 분석한다. 본 연구에서는 가뭄 절단수준의 변화에 따른 한반도 내 가뭄의 특성분석을 위하여 하나의 절단수준으로 고정된 경우의 가뭄특성과 각 년도 월별 특성을 고려하여 절단수준이 지속적으로 변화하는 경우로 구분하여, 가뭄특성의 변화를 분석하였다. 또한 위 두 가지 경우에 대해 각각 가뭄해소 여부를 판단하여 총 4가지 경우에 따른 가뭄 특성을 분석하였다. 가뭄 절단수준의 변화 및 가뭄 해소여부에 따른 한반도 내 가뭄 특성을 분석하기 위해, 가뭄의 지속기간, 심도의 기초통계량 등을 산정하여 비교 분석하였다. 본 연구는 한반도 내의 가뭄특성을 보다 정확하게 해석하기 위해서는 다양한 가뭄정의에 따라 가뭄 해석결과가 나타내는 상대적 차이를 비교할 필요성이 있음을 증명하였다.

• Journal of Chest Surgery
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• v.35 no.3
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• pp.223-226
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• 2002

Background: Thoracoscopic sympathicotomy is an effective treatment in essential hyperhidrosis. However, many patients suffer from compensatory hyperhidrosis. Compensatory hyperhidrosis is a very uncomfortable problem, but the mechanisms underlying compensatory hyperhidrosis are not completely understood. Material and Method: From May 1999 to June 2001, 25 cases of thoracoscopic sympathicotomy at the 2nd rib for facial hyperhidrosis and 116 cases of thoracoscopic sympathicotomy at the 3rd rib for palmar hyperhidrosis were performed in 141 patients. All of the patients were divided into noncompensatory sweating(NCS) and compensatory sweating(CS) group. Each group was investigated according to age, sex, body surface area(BSA), level of sympathicotomy and occupation. Result: The global rate of compensatory hyperhidorsis were 64.5%(91/141). There was no difference between the two groups for BSA, level of sympathicotomy and occupation. Mean age showed 23.2 years old in NCS group and 26.4 years old in CS group(p=0.09). In CS group, 46 cases were male(50.5%) and 45 cases were female(49.5%) and in NCS group, 19 cases were male(38.0%) and 31 cases were female(62.0%) (p=0.16). Conclusion: There were no available statistical data, but there was the fact that old age and male patients had the tendency for compensatory hyperhidrosis. If we have more patient group and consider the patient's family history or psychiatric problems, we will have more valuable data for compensatory hyperhidrosis.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.922-927
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• 2004

Abrasive waterjet (AWJ) cutting is an emerging technology for precision cutting of difficult-to-machining materials with the distinct advantages of no thermal effect, high machinability, high flexibility and small cutting forces. This paper investigated theoretical and experimental cutting characteristics associated with abrasive waterjet cutting of quartz GE214. It is shown that the proper variations of several cutting parameters such as waterjet pressure, cutting speed and cutting depth improve the roughness on workpiece surfaces produced by AWJ cutting. From the experimental results by AWJ cutting of quartz GE214, the optimal cutting conditions to improve the surface roughness were proposed and discussed.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.112-115
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• 2006

본 논문에서는 무인 생산 공정의 선삭 가공 시 발행하는 칩의 처리에 관한 연구를 수행하였다. 선삭시 발생되는 칩은 부품의 정밀도와 표면 조도를 저하시키는 등 품질 저하와 함께 생산성을 저해하는 요소가 되기도 한다. 이러한 칩을, 칩 브레이커를 사용하여 작은 곡률 반경으로 절단함으로써 칩 제거를 효율적으로 제어한다. 그와 함께, 다구찌 기법을 적용하여 최적의 조건으로 칩 브레이커 형상 설계 인자를 도출하는데 그 목적이 있다.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.179-184
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• 1994

In this study a nondimensional parameter, feed/land length(F/L) was introduced, and using this parameter, cutting performance and chip breaking characteristics of the groove and the land angle type chip formers were assessed. Specific cutting energy consumed and shape of broken chip with its breaking cycle time were appraised to find out the ranges of F/L value where efficient cutting and effective chip breaking could be achieved. C type chip was found out to be the most preferable in terms of cutting efficiency.

• Journal of Korea Water Resources Association
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• v.33 no.4
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• pp.437-446
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• 2000

THe drought analysis is performed by applications of truncation level method and conditional probability concept for hydrologic time series in Han river basin. The distributed trend of conditional probability is determined using kriging method for the time series. This study uses daily flowrate, monthly rainfall, and daily high temperature data sets. The daily flowrate data of 12 years(1986~1997) is used for the analysis. Also, the 14 years' data sets(1986~1999) for monthly rainfall and daily high temperature obtained from the National Weather Service of Korea are used in this study. In the cases of flowrate and rainfall data sets, the estimated value corresponding to the truncation level is decreased as the truncation level is increased but in the high temperature data, the value is increased as the truncation level is increased. The conditional probability varies according to the observations and sites. However, the distributed trend of drought is similar over the basin. As a result, the possibility of the drought is high in the middle and lower parts of Han river basin and thus it is recommended the distributed trend of drought be considered when the plan or measures for drought are established.

• Korean journal of food and cookery science
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• v.3 no.2
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• pp.68-74
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• 1987

Objective and subjective methods were performed together for TPA analysis of acorn mook, and their correlations were analyzed. As the result of sensory evaluation, hardness and fracturability were most important factors for prediction of preference. Meanwhile, compression test with Instron Universal Testing Machine revealed that P1(maximum peak in first bite) was very effective factor representing the cheracteristics of first bite, and that P2 the latter peak in first bite) was valuable for prediction of characteristics of second bite.