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.

품종별 감꽃 동결건조 분말의 유효성분 분석

김준한 ( Jun Han Kim ),박석희 ( Seok Hee Park ),문혜경 ( Hye Gyeong Mun ),이인선 ( In Seon Lee ),김종국 ( Jong Kuk Kim ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2006 한국식품저장유통학회지 Vol.13 No.6

감 품종별(도근조생, 고종시, 갑주백목, 차랑, 월하시, 상주둥시)로 감꽃을 개화기에 채취하여 동결건조 분말화한 감꽃분말에 함유된 유효성분을 분석, 비교하였다. 조지방 함량은 도근조생이 57.26%로 가장 높은 값을 보였으며, 유리당 조성은 fructose가 95~310 mg%, glucose는 75~281 mg%, sucrose가 7~28 mg%의 함유량을 나타내었고, 유기산 중 malic acid가 갑주백목(6월4일)에 225 mg%로 가장 많았고, tartaric acid도 189 mg%로 가장 많았다. 유리아미노산 중 hydroxy-L-proline은 월하시에 25.33 mg%, L-citrulline은 상주둥시(5월28일)가 58.83 mg%, L-threonine은 상주둥시(5월28일)가 11.88 mg%로 가장 많았다. 페놀산으로 caffeic acid는 갑주백목(6윌4일)이 1946 μg/100 g, phydroxybenzoic acid는 상주둥시(5월29일)가 417.8 μg/100 g, protocatechuic acid는 갑주백목(6월1일)이 181.1 μg/l00 g으로 가장 많았다. 따라서 감꽃에도 감이나 감잎에 못지않게 유용한 식품성분들과 기능성 성분들이 다량 함유되어 있어 새로운 식품 및 기능성 신소재로서의 가치가 매우 높다고 할 수 있다. This study was carried out to analyze useful components in freeze-dried persimmon flower powder made from six cultivars. The cultivars were Dogunjosang, Kojongsi, Kabjubaekmok, Chalang, Weolhasi and SangjuDungsi. Powder of persimmon flower was prepared by milling after freeze drying at -70℃. Crude lipid was the highest in Dogunjosang (57.26%). Major free sugars of the persimmon flowers were fructose (95~310 mg%), glucose (75~281 mg%)and sucrose (7~28 mg%). Major organic acids were malic acid (225 mg% in Kabjubaekmok (Jun. 4th)) and tartaric acid (189 mg% in Kabjubaekmok (Jun. 4th)). Predominant free amino acids were hydroxy-L-proline(25.33 mg% in Weolhasi), L-citrulline (58.83 mg% in SangjuDungsi (May 28th)) and L-threonine (11.88 mg% in SangjuDungsi (May 28th)). Major phenolic compounds in the persimmon flowers were caffeic acid (1,946 μg/100g in Kabjubaekmok (Jun. 4th)), p-hydroxybenzoic acid(418 μg/100g in SangjuDungsi (May 29th)) and protocatechuic acid(181 μg/100g in Kabjubaekmok(Jun. 1st)). The results suggest that persimmon flowers be potential materials as useful food ingredients.

Clinical usefulness of infrared thermal imaging as a non-invasive screening test for diagnosis of vascular malformations

( Chihyeon Sohng ),( Jun Hong Park ),( Won Kee Lee ),( Jun Young Kim ),( Yong Hyun Jang ),( Weon Ju Lee ),( Seok-jong Lee ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Infrared thermal imaging (ITI), aka thermography, has been used widely in medicine, but been studied rarely its clinical application in vascular malformations (VMs). Objectives: This study investigated validity and usefulness of ITI as a new screening test to differentiate between capillary malformation (CM) and arteriovenous malformation (AVM). Methods: This study included 50 patients with VMs who conducted ITI between 2011 and 2018. They were divided into two groups; CM and AVM, and those with Parkes-Weber syndrome (PWS) were also included in AVM group. Temperature difference (ΔT) between lesional and contralateral non-lesional area was compared using ITI to calculate the maximum ΔT (ΔTmax). The receiver operating characteristic (ROC) curve was then plotted to determine optimal cutoff value of ΔTmax. Results: Of the total 50 patients, 34 were finally diagnosed with CM, and 16 AVM (12 pure AVM, and 4 PWS). AVM group had significantly higher ΔTmax (2.57±1.23°C) than CM group (0.69±0.50°C).The area under the curve of ΔTmax for diagnosis of AVM versus CM was 0.938. The sensitivity and specificity were showed 87.5% and 94.1% (LR+, 14.87; LR-, 0.13) in cutoff value of ΔTmax 1.39°C, and 81.3% and 97.1% (LR+, 27.62; LR-, 0.19) in cutoff value of ΔTmax 1.42°C. Conclusion: The value of ΔTmax measured by ITI was useful to distinguish AVM from CM, so ITI can be employed as a new non-invasive differential screening test for uncertain VMs.

태권도 체육 수업에 대한 고등학생들의 인식도 조사 연구

박준석,조인철,고영철 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.4

The purpose of this study is to establish the educational ideology of Taekwondo by basing on male and female high school students' interest level of Taekwondo in physical education class conducted in school. The subjects were 947 students, including 544 boys and 403 girls, from four different high schools in Gyeonggi province, Busan and Seoul, where Taekwondo lesson was offered. For data analysis, t-test was conducted to find out the differences between the boys and girls, and Chi-square test was used to verify the level of significance. The results from this study is listed as below: Firstly, for the nasality of Taekwondo in physical education, 31.7% answered "so-so" as the highest result. Secondly, concerning whether the educational objectives for each grade were selected to meet their expectations and needs, 38.5 percent found it not quite satisfying and also 34.0 percent of subjects were not considering themselves to be interactive or alert in Taekwondo class. Thirdly, concerning if Taekwondo in physical education is practicing both practical and theory, 36.0% answered "so-so", and concerning if Taekwondo related books are brief and logical so that it is easy to understand, 34.5% answered "so-so" as the highest result. Forthly, concerning if Taekwondo in physical education is helping improve their health and strength, 33.8% answered "so-so", and concerning if it is helping improve their manners and social relations, 34.3% answered "so-so" as well. Lastly, 41.9% perceived the related educational setting in their schools to be "so-so", and 32.7% perceived the improvement effort of conducting Taekwondo in physical education in school as "so-so".

21세기의 테러에 대한 동향과 대응방안

박준석 龍仁大學校 武道硏究所 2004 武道硏究所誌 Vol.14 No.2

It is that operations which centralize in national intelligence service by support of nation are cooperate with private organization public organization and academic worlds. Especially it is going to understand and public information with strengthen of systems, expansion of equipments of terror and factor of environment opposition of plans of terrors and educations are nation, private organization, academic worlds. Further, professional men with theory of terror and practical affairs are as fast as possible coming forwarded in university with security service.

한국 금융기관의 시설경비·경호 현항과 개선방안

박준석,최진영 龍仁大學校 武道硏究所 2004 武道硏究所誌 Vol.14 No.2

In this paper, examine present status of financial institution s facility in USA and Japan which are known as advanced countries of private security industry, and analyze face subject and controversial points. And then, grope improvement plan for efficient security and problems of Korean financial institution s security. As results of study, for improved self-security of financial institutions, followings are the financial institution self-security plans and confrontation plan of private security companies. First, among the financial institutions, crime is increasing to community bank which security is vulnerable relatively than major banks. This is evidence that advanced security equipments are effective to control the will of crime. Therefore, financial institution should install advanced security equipments under the sense of duty that manage customer s property safely by oneself, and cooperate with private security company for better crime prevention activities. Second, criminals are usually propel crime at opening, changing time at lunch, and at closing hour. Because, employees of financial institution are not paying much attention in those loose time. Therefore, non-window personnel s supports are must be provided to make circumstance that window personnel works at right position certainly when starting time or shifting time. Third, when crime is occurred, non-window personnel must issue alarm quickly and request cooperation of the police or private security company. Especially, one of the important suggestion by this paper is that alarm should be issued to in and out side of financial institution along with the police and private security company and establish citizen arrest system which helps arrest criminals by citizen or related agents in neighbor area. Fourth, Security must be managed as multiple system such as automatic alarm device on building walls and vault to issue the alarm when there are unusual noises or vibration of vault because in case of single alarm he, F criminals cut off the alarm line, it could be open state to crime. So, must establish multi alarm system and make criminals not to accomplish crime by delaying entry time. Fifth, to customer who withdrawal cash or check more then certain amount, escort service should be introduced and escort to destination safely as customer protection system even if customer does not ask for. And Followings are confrontation plan of private security companies. First, confrontation ability at initial stage is not enough. Under current security system, it is very hard to reach the spot with crime time even If go out as fast as possible. Therefore, manage manless automatic monitor system thoroughly and set multi-channel warning system so that alarm may issue around police station or private security' company as well as banking facilities neighborhood in case of panic button is pressed in window, and must grope plan of total citizen criminal prevention system that can request neighborhood inhabitants' cooperation. If systematic and synthetic management is accomplished in window, crime can be prevented in some degree. In other words, most of crime at window can be prevented by alarm management system at window, cooperation system with professional security agents and insuring window security agents, etc. Second, securing professionalism of professional security team is urgent. Most of private security company's manpower are not qualified, and it is that they are not much helpful when actual situation occurred. Also, it is truth that their role is limited to carry out preventive patrol activity. Therefore, professional training and education to financial facility staff is required. Moreover, should recruit specially trained manpower at military or police, and it is necessary to consider plan that confront properly in initial state of crime. And the most important thing is holding back criminal's crime wills thru security staffs periodic and systematic confrontation training abut financial facilities crime. Third, professional security school is necessity to educate and train private security staff by each fields. As a plan to this idea, utilizing education and training system of existing school or military, and newly establish professional education and training institute to cultivate professional security staffs. Especially, for financial facility, must aim at operation of the most advanced security equipments. And for cash-in transit vehicles, must used wireless transmitter equipped vehicles and bags obligatorily, so that it is possible to trace the location when it is robbed.

바렉터 다이오드를 이용한 높은 격리도를 갖는 Diplexer 스위치 설계 및 구현

박준석,강명수 국민대학교 생산기술연구소 2004 공학기술논문집 Vol.27 No.-

In this paper, using diplexer structure and varactor diode controlled by reverse bias voltage for diplexer switch gives possibilities to improve isolation and current characteristics. I have newly designed switch with high isolation by application varactor diode corresponding to capacitor of diplexer. The low-pass filter for proposed tunable diplexer passes the microwave signal in the bandwidth for wireless cellular network systems and high-pass filter passes it in the bandwidth for wireless personal communication services (PCS) network systems. As the capacitance of the low-pass filter increases, the cut-off frequency can be moved to low frequency, so that the switch is on state in cellular bandwidth and off state in the PCS bandwidth, in contrast to, as the capacitance for attenuation characteristic of high-pass filter increases, it can be moved to high frequency, so that the switch is off state and on state in the cellular bandwidth, it is possible to improve isolation and current consumption characteristics by application diplexer design methods and varactor diode. I expect that the tunable diplexer circuit and design methods should be able to find applications on MMIC and low temperature copired ceramic (LTCC).

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.

알코올 사용과 스트레스와의 관련성

전진용,오동열,구민성,이준석,천근아,박웅섭,김상아 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.4

Objectives : This study was designed to assess the relationship between alcohol use and stress. Methods : The study subjects were 1,261 people who drink among the 2,565 people who lived in Gangneung. We investigated the sociodemographic characteristics, Short Form-12 (SF-12), Global Assessment of Recent Stress (GARS) and Alcohol Use Disorder Identification Test (AUDIT). Results : In Problem drinking group the GARS was significantly positively associated with the AUDIT (p=0.02). In Social drinking group sex (p<0.001) and age (p=0.02) is significantly associated with the AUDIT. Conclusion : This study showed the significantly positively association between stress and alcohol use. We think that the intervention and active management of the stress can prevent the alcohol problem.

한국 민간보안.시큐리티 산업의 발전방안

박준석 용인대학교 2006 용인대학교 논문집 Vol.24 No.-

The device for the important assignment of the healthy bringing up and the preservation of public peace should be examined, first in legal, systemic term, second the terms of quality improvement for security, guard, security guard, third the terms of cooperate important for private, security, guard, security guard, forth total security system expulsion, change of people, paradigm shift about private security , guard, crime prevention, expulsion and supporting. When considering real term, a policeman on special guard assignment system and private security guard , system's combining or unifying should be set up quickly to take a role of partner. Lastly, the access will be needed such as security industry's variety, speciality, education, guarantee of job, well fare etc like America lessen risk management system's loss, spread out. So, it is needed to access security total consulting industry, government, organization(military, police, security service, national intelligence service etc) and it is considered cooperate system of security company related area(education organization, academy world) and government organization (military, police, security service, national intelligence service) is very necessary soon. Risk management manual, D.B. expulsion should be variously developed.