와전류법을 이용한 크랭크샤프트 크랙 검사

정성훈(Sunghoon Jeong),김광희(Gwanghee Kim),이희범(Heuibom Lee) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

Material in automotive industry has changed to reduce cost of manufacturing. In that aspect, micro-alloyed steel used for material of crankshaft has substituted quench and tempered steel to have equal quality and result in a drop in cost. The quench and tempered steel is usually treated by heating. But micro-alloyed steel which just add alloying elemnts such as vanadium, boron and so on is applied without overall heat treatment. The surface of crankshaft made with micro-alloyed steel is locally processed by induction hardening. The process can cause a crack on grinded surfaces because of residual tensile stress. Therefore crack inspection is required. Magnetic testing is used manually in line. Magnetic testing is subjective to detect defects. Eddy current(EC) testing use electronic signal automatically and is objective to detect cracks. In this paper, it is estimated that eddy current method is valid.

샤프트 표면결함 검출을 위한 비전검사 시스템 개발

정성훈(Sunghoon Jeong),류성희(Sung Hee Yoo),정대현(Dae Hyeon Joung),이희범(Heui Bom Lee) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

The quenched and tempered steel is usually treated by heat treatment. But micro-alloyed steel including alloying elements such as vanadium, boron and so on is applied without overall heat treatment. The surface of crankshaft made with micro-alloyed steel is locally processed by induction hardening. The process can cause a crack on grinded surfaces when residual tensile stress is higher than strength of the material. Therefore crack inspection is required. Various inspection methods such as magnetic testing and eddy current testing have been used for detecting surface defects of shaft in automobile engine and transmission. Magnetic testing is to see fluorescent lines by condensed magnetic particles on defects and can have an error because of worker’s subjective judgment. Eddy current testing is difficult to be flexible because it should have many sensors to detect surface defects. Also, it has limitation in detection ability because the higher sensor sensitivity is the more noise is included. The eddy current sensor can detect cracks above a depth of 0.1mm. In this paper, it is investigated that vision inspection method is valid in ability of detection, classification, measurement of surface defects such as crack, contamination, scratch, and pores.

노인의 신체활동 수준과 의료이용의 관계

정성훈 ( Sunghoon Jeong ),김홍수 ( Hongsoo Kim ) 대한보건협회 2020 대한보건연구 Vol.46 No.3

연구목표 : 본 연구는 노인의 신체활동 수준과 의료이용의 관계를 분석하는 것을 목적으로 한다. 연구방법 : 본 연구는 한국의료패널 제9차(2015년)자료의 65세 이상 노인 2,997명을 대상으로 국제신체활동설문지(IPAQ)를 활용하였다. 본 연구에서는 IPAQ을 활용하여 신체활동 수준을 비활성, 최소 활성, 활성의 세 가지 범주로 나누고 신체활동수준과 의료이용의 관계에 대해 다중로지스틱회귀분석과 음이항회귀분석을 수행하였다. 연구결과 : 한국 노인의 신체활동 수준은 비활성 50.5%, 최소 활동 41.2%, 활동 8.3%로 나타났고 신체활동 수준이 높아짐에 따라 의료이용률, 입원횟수 및 일수가 감소하는 것으로 나타났다. 결론 : 노인의 신체활동 수준과 의료이용과는 부의 상관관계가 있다. 추가적인 인과관계 연구가 필요하며, 노인을 위한 건강증진 정책으로 신체활동수준 개선 전략이 지속적으로 추진되어야 한다. Objectives : The purpose of this study was to analyze the relationship between Physical Activity Level (PAL) and health care utilization in the older adults. Methods : This study used the International Physical Activity Questionnaire (IPAQ) for 2,997 older adults aging 65 or above in the 9th data of the Korea Health Panel (2015). Multiple logistic and negative binomial regression analyses were performed to analyze the relationship between PAL and health care Utilization by dividing into three categories: inactive, minimally active, and active. Results : PAL of the Korean older adults were shown to be 50.5% for inactive, 41.2% for minimally active, and 8.3% for active. As PAL increased, health care utilization, hospitalization, and days of inpatient were shown to decrease. Conclusion : There is a negative correlation between the PAL of older adults and health care Utilization. Causal research will be needed and the strategies for improving PAL should be continuously driven as a health promotion policy for older adults.

SAF를 위한 자동계획기법 구현 사례

김정윤,최대회,이상진,정성훈,Kim, Jungyoon,Choi, Daehoe,Lee, Sangjin,Jeong, Sunghoon 한국시뮬레이션학회 2014 한국시뮬레이션학회 논문지 Vol.23 No.4

Our Automatic Replanning enables simulation entities to execute goal oriented behavior planning by dynamic behavior linking. Existing methods especially in Semi-Automated Forces (SAF) are mainly executing strict plans which are given at initial stage, thus they are not effective to cope with contingencies especially in a human in the loop simulation where humans interrupt. Moreover, those usually suffer from explosion of behavior combination in attempt to describe all possible countermeasures, and such combinations may be prone to being inconsistent to the situations. Our method generates behavior sequence in which behavior are linked from the goal in the manner of back-propagation. Each behavior has tags of pre/post-conditions. The tags are linked dynamically according to a certain contingency. The method is being applied to a national defense research project to show feasibility. 본 연구는 모의개체로 하여금 동적행위연결을 통한 목적지향 행위계획을 수행토록 하는 기법의 구현사례로서 재계획기법을 소개한다. 기존의 행위처리기법, 특히 Semi-Automated Forces (SAF)에서는 모의 초기에 주어진 정해진 계획을 단순히 수행하는 수준에서 크게 벗어나지 않는다. 따라서 인간의 판단 같은 예측불허 상황이 발생하는 (Human in the loop) 모의에서 기존 기법은 상황대처에 미흡하다. 또한 그러한 기법은 돌발상황 대응을 위한 광범위한 경우의 수를 고려하다보면 행위조합 폭증 문제를 겪을 수 있으며, 그러한 조합이 상황에 부합하지 않을 수 있다. 재계획기법은 역전파(back-propagation)를 활용, 목표달성을 위해 필요한 행위들을 검색, 연계하는 자동계획기법 구현사례이다. 이 기법은 행위에 태그(pre/post-conditions)를 부여, 동적으로 행위들을 연결한다. 본 논문은 기법의 실효성 입증을 위해 국방분야의 연구과제에 적용된 성과를 소개한다.

한국형 헬기의 다중센서 위협 시뮬레이터 설계 및 구현

박헌우(Hunwoo Park),정용웅(Yongwoong Jeong),정성훈(Sunghoon Jeong),노상욱(Sanguk Noh),고은경(Eunkyoung Go),김숙경(Sookyung Kim) 한국정보과학회 2008 한국정보과학회 학술발표논문집 Vol.35 No.1

전장환경에서 헬기는 헬기생존체계의 다양한 센서를 통하여 수집한 데이터를 기반으로 헬기에 대한 위협을 식별한다. 헬기의 성공적인 임무 수행 및 생존을 위하여 헬기에 대한 위협을 반복적으로 확인할 수 있는 시뮬레이터의 구현은 필수적이다. 본 논문에서는 (1) 헬기의 센서가 수신하는 위협요소를 정의하는 온톨로지 생성기, (2) 전장환경과 유사한 위협을 다양한 분포로 생성하는 위협자료 생성기 및 (3) 다양한 전장 시나리오에서 센서들이 수집한 데이터를 통합하여 위협의 방향과 정도를 사용자에게 실시간으로 보여주는 그래픽 화면표시기를 개발한다. 구현한 헬기의 다중센서 위협 시뮬레이터는 다양한 위협을 생성하는 자동 시나리오 생성기를 이용하여 위협 개체의 탐지 및 분류를 반복적으로 수행한다. 위협 시뮬레이터를 활용한 실험에서 동일한 위협에 대한 통합 정확도를 측정하였다.

섬망 치료에서 Aripiprazole과 Haloperidol의 효과 : 무작위 개방 연구

이준영(Joonyoung Lee),조현영(Hyunyoung Jo),정운선(Unsun Chung),이병대(Byung Dae Lee),이양현(Yanghyun Lee),정성훈(Sunghoon Jeong) 대한생물치료정신의학회 2007 생물치료정신의학 Vol.13 No.2

Objectives:Delirium is a common condition frequently seen in consultation-liaison psychiatry. Antipsychotic drugs are the primary treatment for symptoms of delirium. Typical antipsychotics, especially haloperidol, have been used as the mainstay of pharmacological treatment of delirium. With the introduction of atypical antipsychotics, the clinical usefulness of these medication has also been investigated for delirious patients. The purpose of this randomized, open-clinical trial is to compare the clinical efficacy and tolerability of haloperidol and aripiprazole for the treatment of delirium. Method:45 patients with a diagnosis of delirium were enrolled between July 2005 and May 2007 in this study. They were randomly assigned to be treated with a flexible-dose regimen of haloperidol or aripiprazole. The Korean version of Delirium Rating Scale(K-DRS) and other measures related with delirium had been used repeatedly until the K-DRS score reached 12 or less which we defined as the criteria for recovery from delirium. 22 subjects in haloperidol group and 19 in aripiprazole group completed the study. Results:The mean dosage of antipsychotics for delirium was 3.0±1.6㎎ of haloperidol and 5.5±1.5㎎ of aripiprazole which was relevant to 150.5±83.6㎎ and 73.7±20.9㎎ of chlorpromazine respectively. Aripiprazole was effective to subside the delirium symptoms at less dosages than haloperidol. There were no significant group differences in the score of K-DRS, K-DRS-R-98 and MMSE-K at baseline as well as final assessments. There was no significant difference in duration of treatment and clinical improvement between the groups. Most of the patients were well tolerated to the adverse events of each antipsychotic drug but only two patients in haloperidol group showed extrapyramidal symptom. Conclusion:Aripiprazole may be more useful than haloperidol in patients with delirium because of its safety and low dose effectiveness, especially in aged patients. Further double-blind placebo-controlled studies with a large sample size will be necessary.