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.

스포츠 매니지먼트활동에서 매니저들의 책임 수행에 관한 연구

박준석,김정묵,정석현,조영웅,이영성 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

Sport has taken a position as significant influence all over the world for a long time. These days, sport must exist with us in order to provide pleasure, so people have a tendency to expect it what happens to them. Therefore, a number of sport teams and competitions are able to stimulate people to be interested in sport. Sport event, information, equipment, and sport player management need systems which accompany with security and pleasure because the systematical managements establish security, and help sport players not to make an error that is a fountain of good quality game. Thus, sport players improve their ability, so the audience are willing to pay to see the game. In order to extend the power of sport influence, sport should be organized in terms of managing sport processes well. Unfortunately, the system of management for sport is not still adequate and organized in Korea. In other words, many materials must be sporadic, and newspapers or magazines have treated of sport management with fragmentary knowledge so far. Today, systematical management is essential to all segments of the sport industry, professional or amateur, school or club, private or government at any level community or individual. Hopefully, this research will be instructive as a starting point to derive a special quality of sport management which is suited to korea sport market by comparing to other management systems in order to formulate organized management industry.

한국 민간경비업체의 마케팅전략개선방안

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

Korea's private security guard industry has made rapid progress since the early 1960s and has been realizing security and crime prevention around our lives since the 1980s. Despite its high quantitative growth and remarkable external progress compared with its short history, however, relatively few researches have been done on the area of qualitative growth, i.e. on ways of strengthening its competitiveness through diversification of security guard management enterprises. Private security is a high value-added industry whose high growth may be expected in future. Apart from its quantitative growth so far, aggressive market-oriented approaches and service marketing strategies through management system diversification for its qualitative growth are required for the industry. In order to realize this research goal, this study has been conducted by carrying out literature researches and analyses via interviews with some relevant people. As a result, the following ways of improving the service marketing of the private security guard industry have been suggested. First, differentiation and specialization are required for the product strategy segment. Differentiated and specialized guarding of facilities through excellent human resources are required. As for the guarding of machines, composite and digitalized products suitable for the characteristics of market segmentation need to be developed. Moreover, security guard companies should establish their own branded images, increase their market share by using their products and human resources, and adopt a brand superiority strategy. They need to develop new products suitable for the digital era. Research and development and investment should be continued in order to create new products. It is necessary to develop various and differentiated products after segmenting target markets for products. For the sake of the qualitative improvement of products (services), security guard companies need to strengthen cooperation between the relevant business and academic circles and their cooperative system with the police to improve their crisis management ability and keep their after-sales service and reward systems in best condition. Second, as for the price strategy segment, it is necessary to take into consideration the market structure where businesses are divided into large and small companies. Large companies need to find new overseas markets and offer expensive products (services) on the basis of their excellent material and human resources while small companies should gain price competitiveness by developing differentiated products (services) based on their business circumstances. They also need to enhance their price competitiveness through new products. They should reduce the relative importance of cost and develop new products proper to the business levels of respective companies to find new markets and gain price competitiveness. The money saved by reducing labor costs through outsourcing, etc. should be used for a new project or a price differentiation strategy. Third, as for the distribution strategy segment, security guard companies need to employ and train excellent human resources and establish a segmented indirect distribution network by expanding their dealership and sales agent networks. Brisk electronic commerce is necessary because of increasing Internet users. Electronic commerce makes it possible to provide support for the distribution networks of private security guard companies, which are centered around Seoul and surrounding areas, and to expect cost effectiveness related to security guard service performance due to expansion of sales agent networks on the part of small security guard companies. It is getting easier for Korean private security guard companies to advance abroad because many Korean companies of other business lines are making brisk inroads into overseas markets. They can expect synergies from selling new products developed in Korea to foreign countries or advancing abroad by setting up a joint venture with foreign companies. Fourth, as for the sales promotion strategy segment, sales people must specialize in their sales activity area since most private security guard companies pursue sales promotion activity focusing on sales people. Security guard companies should try to increase the efficiency of sales people s sales activity by employing and training excellent human resources, and positively adopting an ability-based annual salary system and an incentive system. They also need to use aggressive publicity and advertisement strategies through mass media to instill brand awareness in people so that they may be interested in buying products. Small companies must use a sales promotion strategy through the Internet in order to reduce costs. Advertising or publicizing products on the Internet makes it possible for them to provide services for their customers at low cost without the inconvenience of any limited time and space. They also can make direct product publicity and advertisements through events or mailing services. The Internet and electronic commerce are becoming more and more important as a means of business and will be a useful tool for securing future and potential customers.

공조시스템을 적용한 석실 고분내 온ㆍ습도 분포

전용두,이금배,박진양,고석보,전희호 公州大學校 工學硏究院 生産技術硏究所 2005 論文集 Vol.13 No.-

Although the importance of good conservation of historic sites including ancient royal tombs is well aware, still not much attention has been paid for the facilities and systems to preserve those historic sites, which includes precious artifacts as wall paints and carved works, etc. Even the general understanding about the environment of the underground space of tombs is not satisfactory. In Korea, researchers have recently begun addressing the above issue and are making efforts to develop suitable HVAC(heating, ventilating and air-conditioning) systems for conservation of tombs. An experimental investigation was carried out to study the behavior of the HVAC system installed for a tomb. This tomb resembles in size and shape the original stone built tomb of Baek-je Dynasty, which dates back to 6th Century in southwest part of Korean peninsula. In this study, an HVAC system for a tomb(D×W×H=1.3m×3.0m×1.2m) was installed to maintain sui표 indoor conditions for conservation of tomb. The temperature and humidity inside the tomb were measured different of the setting. Finally, performance of the HVAC system is presented and discussed.

경부 청소술 후의 승모근기능

박준명,박동식,정광익,이언석,노영수 大韓再活醫學會 1998 Annals of Rehabilitation Medicine Vol.22 No.2

국내기업의 테러위협국가 위협의 예방과 과제

박준석 용인대학교 인문사회과학연구소 2009 인문사회논총 Vol.- No.16

As a plan for protection and prevention of domestic enterprises, mutual intimate cooperation in the need to change perception of CEOs, the institutionalization of the companies' counter-terrorism measures system, the cooperation in international agreement or mutual assistance, the help of academic world and private security industries, the necessity for enactment of counter-terrorism laws, the status and directions against the terrorism and stationing and education of experts, and protection of exchanging cultures, sports, and education and visits should be formed. As an option for protecting domestic enterprises getting into state sponsors of terrorism against threat of terrorism, there is the necessity that National Intelligence Service (Integrated Center against Terrorism) organizes integrated management system with administrative organs which are related to itself such as KOTRA, KCCI, KITA, KOICA, embassies, consulate offices, the police, and the military. Moreover, as a protection, it is necessary to make experts at the terrors and security be on duty all times focusing on the state sponsors of terrorism such as Africa and the Middle East to not only prevent also restore and cope with terrorism. Following above, formating network of information of domestic companies entering into states sponsors of terrorism, and studying of cultural, religious, and linguistic parts have to be controlled under the national crisis management. Additionally, the long-termed mutual cooperation between domestic enterprises should be researched. Also, in resources diplomacy of current government, it is considered that the domestic industries' system of protection, prevention, confrontation, and recovery for legal, systematic, administrative, integrated crisis management should be gradually studied.

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).

한국에서 온라인서비스제공자의 법적 책임론이 나아갈 방향

박준석 慶熙大學校 경희법학연구소 2008 경희법학 Vol.43 No.3

The legal theory or regulation on the secondary liability of Online Service Provider is roughly divided into two parts, liability requirement and liability limitation requirement. For the OSPs’ liability requirement portion, Korean court seems to have taken unified position in both users’ copyright infringement case and defamation case, pointing out that Joint Tort-feasors rule in Article 760, Clause 3 of the Korean Civil Act is the statutory ground for OSPs liability requirement. For the liability limitation portion, meanwhile, there has been inconsistency of liability limitation requirement in Korean Copyright Act and The Act on Promotion of Information and Communications Network Utilization and Data Protection, thereby making OSPs in Korea suffer from unnecessary legal uncertainty. OSPs’ secondary liability rules in Korea should not follow the US model in which it has been traditionally divided between copyright infringement and defamation. Korea has not differentiated copyright infringement case from other infringement cases including defamation in the secondary liability requirement portion, whereas US has done. Moreover, it can’t be missed that there is a plausible argument for the unification of OSPs’ liability limitation rules even in US. Therefore, OSPs’ secondary liability rules in Korea should be unified over all infringement areas by users, regardless of copyright infringement, defamation, etc., to settle the legal uncertainty in Korea, mentioned above. While the best way would be a new unified law on OSPs’ secondary liability limitation, if it would be severely hard, the second best way to do so is to make immediate amendments harmonizing OSPs’ liability limitation clauses in both acts, Korean Copyright Act, Article 102 & 103 and the Act on Promotion of Information and Communications Network Utilization and Data Protection, Article 44-2. It’s a wrong conception at least in OSPs’ secondary liability area, the way of thinking that defamation cases related to the freedom of speech should be treated differently from copyright infringement cases at all times. In addition, the following differences just can be merely secondary considerations, but never make it very hard to unify OSPs’ secondary liability rules; i) online defamation is usually done through Bulletin Board System rather than Peer to Peer network which has been one of main devices for online copyright infringement, ii) it’s harder in online defamation case to judge the legality of the information at issue and control illegal information than in online copyright infringement case, iii) there is a relatively stronger need to identify direct infringers in online defamation than in online copyright infringement because the former case has relatively fewer infringers than the latter and only the former case has irreparable harm which can’t be compensated by monetary remedies.