Numerical Analysis of Radio‑Frequency Inductively Coupled Plasma Spheroidization of Titanium Metal Powder Under Single Particle and Dense Loading Conditions

Jun‑Seok Nam,Eonbyeong Park,Jun‑Ho Seo 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.4

In order to allow more practical prediction of RF (radio-frequency)–ICP (inductively coupled plasma) spheroidizationresults of titanium metal powder, numerical analyses under single particle and dense loading conditions were carried outand the results were compared. First, both of the numerical results for Ar inductively coupled plasma with the power levelof 30 kW revealed that the injected particles can experience not only spheroidization by melting, but also size reduction byevaporation. In addition, this size reduction was found to strongly depend on the initial sizes of the injected particles, due tothe relatively short heating time. For example, the 100 μm Ti particles were computed to hardly experience size reduction byevaporation regardless of feeding rates. However, relatively small Ti particles < 100 μm can be rapidly heated up to boilingpoints during the short flight of plasma, resulting in the size reduction by the surface evaporation. In particular, numericalresults under dense loading condition showed that the final sizes of these small Ti particles can be changed depending onthe feeding rate. For example, a single 60 μm Ti particle was calculated to be a 51 μm spherical Ti particle due to the excessiveheating. However, with the increase of feeding rate up to 1.0 kg/h, the final sizes of the as-treated Ti powder couldbe improved to 55 μm due to the plasma temperatures decreasing through complicated plasma–particle interactions. Bypredicting the relationships between the feeding rates and the initial diameters of Ti powders at a given plasma power level,numerical modellings under single particle and dense loading conditions can help in optimizing the RF–ICP spheroidizationprocess of titanium metal powder.

국내은행 데이터베이스마케팅전략에 관한 연구

徐俊奭 慶一大學校 1999 論文集 Vol.16 No.4

Recently, there has been rapid increase in database marketing between domestic banks and foreign banks, reflecting the change of world and domestic economic enviroment. The purpose of this study are 1) to find out comparative study on database marketing among Korean, Japanese and American banks 2) to evaluate possible implications for Korean banks's database marketing strategy and consider the effcient countermeasures of Korean banks.

한국만화산업의 수출경쟁력 강화방안에 관한 연구

徐俊奭,徐敏敎 慶一大學校 1999 論文集 Vol.16 No.4

Recently, there has been rapid increase in Korean firms' export of cartoon products, reflecting the change of world and domestic economic environment. The purpose of this study are 1) to find out results of comparative study on cartoon industry between Korea and Japan 2) to evaluate possible implications for Korean firms' export of cartoon products and consider the effcient countermeasures of Korean firms.

응급실에서 소아환자의 진정제로서 케타민(Ketamine)의 사용

서정필,박준석,황태식,장석준,김승호 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Ketamine use in emergency room has been increased. It has rapid onset of action and appropriate duration of action. It does not need endotracheal intubation and produces potent analgesia, sedation, and amnesia. The object of this study is to determine the safety and the degree of physician's satisfaction in relation to ketamine use. Materials and Methods: This is a prospective study using protocol. Pediatric trauma patients who need sedation were given IM ketamine(4 ㎎/㎏) and atropine(0.01 ㎎/㎏) in a same syringe. Monitoring of patients was done by EM residents and complications of ketamine use were recorded. Physician's satisfaction was also recorded after the procedure. Results: Intramuscular ketamine was administered 54 times, mainly for laceration repair. Physicians completed protocol for 51 of treated children. The median time for onset of sedation was 6.5±2.4 min, and duration of action was 32.4±10.8 min. Hypersalivation occurred in 9.8%(n=5); random movement 3.9%(n=2), emesis during procedure(n=1), emesis at home(n=1), and transient oxygen desaturation(n=1). All were quickly identified and treated without specific airway management and sequelae. Of 84% of physicians was satisfied with ketamine use for pediatric sedation. Conclusion: Intramuscular ketamine can be administered safely and satisfactorily in emergency room to facilitate pediatric procedures in conjunction with a defined protocol and appropriate monitoring.

경호상황에서 태권도기법의 적용방법에 관한 연구

박준석,서민학 龍仁大學校 武道硏究所 2004 武道硏究所誌 Vol.15 No.1

This study shows how to apply Taekwondo as a Protectional Martial Art Generally every learning territory is divided into cultural and social science and natural science. In the same manner, the study of guarding should be broken into parts so as to make the most of guarding characteristics. I think that Protection Martial Art will develop in learning because it can motivate Taekwondo participants to study it. I will attempt to show a developing study of Taekwondo as a Protection Martial Art. A Guard is a final method in which deals with each kind of threats. The timing, the place and the way of attempt to inflict an injury is decided by the attactor. The situation of attact is also has many variables. If there isn't a Guard Martial Art or the bodyguard is irresolute, it is difficult to control the attactor. Therefore, the ultimate aim of Protection Martial Art is not only to protect a guarded person from danger through complete training, but also facing an attact and controling it effectively. In order to insure the guarded person's life from the harmer, the bodyguard has to perform his duty from a high degree of training. So training in Protection Martial Art is a necessary condition. When the bodyguard faces an attact and deals with it, he has to grasp and meet the situation - the environment, the direction and the way of attact. Also recognize the a kind of weapon, the attactor's skill and ability and so on. A high degree of guard technics and Guard Martial Art is essential to face and deal with an attact. Owing to establish Protection Martial Art systematically, this shows how to apply Taekwondo training technics to Protection Martial Art and how to deal with a situation of guarding in the event of attact by using basic technics from Taekwondo. First, by studying the system of Protection Martial Art based on Taekwondo, I developed Taekwondo training technics as a Protection Martial Art. Second, "Stance posture" should be neat and sharp. I intend to show the posture-"Parallel Stance"- which is easy to offend and defend in every direction. Moreover it is more developed than it was. Third, I show a desirable "Stance posture" as a guard's position, so that the guard can deal with the dangerous situation promptly and properly. Fourth, I try to show the way how to control an accidental occurance by using a based action and an applied action from Taekwondo as a guard technic. Therefore, I think that the system of Protection Martial Art based on Taekwondo should be studied and Taekwondo should be established as a Protectional martial art. Training Taekwondo as a Protectional martial art enables one to handle any unexpected situation by mastering its theory and basic skills. I consider that we should practice Taekwondo technics through a real model to deal with various dangerous situations.

독성물질의 세포사 기전 및 세포사 유발물질의 검색법 개발에 관한 연구(Ⅰ) : 독성물질로 인한 파킨슨병 모델에서의 세포사 기전 연구 Study on the cell-death mechanisms of toxin-induced parkinsonism

강태석,김종민,서경원,김영옥,김준규,오재호,이윤동,김규봉,오정자,송연정,임종준,전범석,문전옥,최광식 식품의약품안전청 2000 식품의약품안전청 연보 Vol.4 No.-

MPTP 독성물질이 도파민성 신경세포에 선택적으로 작용하여 산화성 손상에 의한 신경세포사를 일으키는 것을 이용하여 파킨슨병의 동물모델을 만들고, 이를 통해서 아폼토시스를 비롯한 포사의 기전에 대한 연구 및 너코틴의 신경세포 보호효과 여부를 판정하는 실험을 병행하고자 하였다. 파킨슨꾐의 동물모델을 MPTf 독성 물질을 이용하여 확립하였으며, MPTP(30mgag, i.p.)를 투여한 후 1, 2,3, 4, 5일째 흑질 조직을 채춰하여 tarm로 박걸하여 tyrosine hydroxylase 면역조직화학염색을 수행하여 cell countif우한 결과, control은 57.635ce11s, 1일째 친.OfDells,2일째 57.9±6cells,3일릴 없.3±죠ells, 4일째 49.0츠3cells, 5일째 39.4±Scells료 4, 3일째 뚜렷한 신경세포 수의 감소를 보였다. 신경세포사 기전 규명을 위한 아폼토시스 분걱에서는 벼PTP 투여 후 1, 2, 3, 4, 5일째 조직을 채취하여 Hoechst staining, TUNEL staining을 수곡하였는데 양성 반응을 보인 신경세포는 관찰되지 않아. 아폼토시스로 인한 세포사가 관찰되지 않았다. bIPTP 파킨슨병 동물모델에서 nicotine 보호효과 탐색에 관한 실험은 nicat푸e 0.2mgAg을 5일 퐁안 투여 후 리『fP(30mgag)를 CS7Bt/6 마은스에 복강 내주사로 nicotine과 병용 투여한 후 1, 2, 3, 4, 5일째 뇌를 적출하땄다. 신경세포사가 뚜렷이 관찰되기 시작하는 4, 5일째의 신경세포 수의 감소 정도를 20. 30% 정도 약화시키는 경향을 보였으나, nicotine 보호효과에 대한 추가 실헝이 현재 수행 중에 있다. The cause of Parkinson's disease (PD) is largely unknown. However, free radical toxicit? may plaf a role ip. the degeneration of substantia nigra, which is the Hajorfocus of pathological damages in PD. Recently, a neuroprotective effect of nicotine in PD has been suggested. Therefore, the mechanism of neurodegenerafion and protective potential o( nicotine in PD were investigated in the experimental modeB of Pll using a neurotoxin, C57BL/6mice were administered with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg,j.p.). The degree of neurodegenerafion was determined by immunohistochemical stainiHB oftyrosine hydroxylase (TH). TH-positive cells on nigral sections were found 56.0 ±4, 57.9 ±6,52.315ce11s, 49.0±3cells, and 39,4±Scells at days 1, 2, 3, 4, 5, respectively (controls : 57.6±Scells). Hoechst and TUNEL staining showed no evidence of apoptosis. The exandnation on themice co-adrunistered with nicotine(0.2mgAg) and MPTP(30mgag) revealed a tendency ofnicotine protective effects. At days 4 and 5, the degree of TH-positive cells was decreased by20-30%, In corclusiffn, the role of apoptosis was not evidenced in this MPTP modeB of PB.The possible proteccon by nicotine should be elucidated with further studies.

캘리포니아주의 관상동맥 우회술 위험도보정 결과평가 사례 연구

윤석준,서현주,박형근 한국의료QA학회 2004 한국의료질향상학회지 Vol.11 No.1

정신분열병 환자에서의 한국어판 사회적응 척도의 개발 : 신뢰도 및 타당도 연구

김철권,서지민,김상수,조진석,하준선,김정옥,변원탄 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.6

연구목적: 정신분열병 환자의 사회적응 정도를 측정하는데 사용되는 사회적응 척도의 한국어판을 개발하기 위함이다. 방 법: 사회적응 척도를 번역한 후 정신분열병 환자 67명과 정상인 78명을 대상으로 신뢰도와 타당도를 검증하였다. 결 과: 자료분석 결과 검사-재검사 신뢰도는 0.85, 검사자간 신뢰도는 0.89, 내적 일치도는 0.87로 높은 수치였다. 변별 타당도를 검증하기 위하여 정신분열병 환자군과 정상 대조군을 비교한 결과 정신분열병 환자군에서 사회적응 정도가 유의하게 낮았다. 구성 타당도를 알아보기 위하여 10개 영역간의 상관관계를 측정한 결과 성적적응 영역을 제외한 모든 영역들에서 유의한 상관관계를 보였다. 본 척도의 전반적 평가 영역 결과와 GAF 결과간의 상관성을 통해 간접적으로 검증한 공존 타당도 역시 유의하였다. 결 론: 한국판 사회적응 척도는 우수한 신뢰도와 타당도가 입증되었고 나아가 정신분열병 환자의 사회적응 정도를 평가하는데 유용하게 사용되어질 수 있을 것이다. Objectives: The purpose of this study was to develop the Korean version of the Social Adjustment Scale Ⅱ-Revised Version(KSAS Ⅱ-RV) in the schizophrenics. Methods: KSAS Ⅱ-RV was administered to 67 schizophrenic patients and 78 matched normal controls for examining the reliability and validity. Results: Data analysis showed statistically significant reliabilities and validities of KSAS Ⅱ-RV. The test-retest reliability, inter-rater reliability, and internal consistency for total scores of KSAS Ⅱ-RV were 0.85, 0.89. and 0.87, respectively. Evidence for discriminant validity of KSAS Ⅱ-RV comes from the results that the mean scores of schizophrenic patients were significantly high than those of normal controls. Construct validity was assessed by calculating the 10 inter-subareas correlations of the KSAS Ⅱ-RV, and all except the sexual adjustment area were statistically significant. Significant correlations between the global area scores of KSAS Ⅱ-RV and those of Global Assessment of Functioning Scale lend support for the concurrent validity of this instrument indirectly. Conclusions: KSAS Ⅱ-RV was found to be a valid and reliable instrument which can be used to evaluate the degree of social adjustment in the schizophrenic patients.

주의력결핍 과잉행동장애 아동의 지적수준에 따른 정신병리와 실행기능의 차이

천은진,서완석,이종범,김진성,구본훈,송창진,성형모,배준용,배대석 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.4

To investigate psychopathoIogy and executive functions of attention deficit hyperactivity disorder (ADHD) children according to intelligence level, this study included 197 ADHD children who visited the outpatient department of neuropsychiatry of YeungNam University Medical Center, from July 2000 to June 2002. The children were divided into groups based on their intelligence levels. They were compared by the Personality Inventory for Children (PIC), Conncers' Continuous Performence Test (CPT), and Wisconsin Card Sorting Test (WCST). There were significant differences in PIC, on the subscales of verbal development, socialization and autism. In the CPT, there was no significant difference. In the WCST, there were significant differences in the total number of errors, the number of perseverative errors, the number of completed categories and the number of trials needed to complete the first category. Considering these results, the intelligence level of ADHD children is related to their disabilities and behavioral symptoms.Executive functions such as abstract thinking, categorization, working memory and flexibility had significant relationship to the intelligence levels of ADHD children. Therefore, the intelligence level of children with ADHD influences the higher executive functions of regulating attention and information processing rather than attentional functions and capacity alone.

버스 정차시간 분석

강영균,서준석,고승영 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

The time spent by passengers to board and alight buses is an important component of the total bus travel time. On average, about one fifth of the total travel time of a bus is spent at bus stop. If this stopped time due to boarding and alighting could be reduced, the saving of total travel time would be reduced also, and this contributes to the efficiency of route operation and vehicle fleet usage. So, this paper defined several kinds of times which are measured in this research of passenger boarding time, alighting time and acceleration - deceleration time. Also, this paper developed a model for bus boarding and alighting time as a function of factors such as fare system, vehicle design and the difference of travel time, and to get the value of bus acceleration -deceleration time in particular factors such as vehicle design and bus stop design.