Effects of Variation of Heat Flux Released from the Meniscus on the Surface Shape of the Solidified Shell During Continuous Casting

Yong‑tae Kim,Kyung‑woo Yi 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

Mold oscillations, widely used in continuous casting for infiltrating the mold flux between the mold and the solidified shell,change periodically the heat flux from the meniscus to mold. These variations of the heat flux affect the solidification behaviornear an initial solidification position. Because the surface shape of the solidified shell is influenced by the initial solidificationbehavior, it is important to understand the relation between the mold oscillation, the heat flux and initial solidificationbehavior. In the present study, we developed a numerical model that simulates the flow and thermal behavior of the moldflux near the meniscus. Using this model, we analyze the effects of the variations of the heat flux from the meniscus on theinitial solidification position and suggest the formation mechanism of the oscillation marks (OMs) and the hooks. Also, wewill present quantitative results about the depth of the OMs and the length of the hooks at the conditions used in the presentstudy. The factors that influence the hooks’ types and the causes of the irregularity of the shell surface are also discussed.

Genome-wide investigation of a Korean synthetic breed, Woori-Heukdon using the Illumina PorcineSNP60K BeadChip

Yong‑Min Kim,Ha‑Seung Seong,Jung‑Jae Lee,Da‑Hye Son,Jin‑Su Kim,Soo‑Jin Sa,Young‑Sin Kim,Tae‑Jeong Choi,Kyu‑Ho Cho,Joon‑Ki Hong,Jung‑Woo Choi,Eun‑Seok Cho 한국유전학회 2020 Genes & Genomics Vol.42 No.12

Background: Woori-Heukdon (KWH) is a Korean synthetic pig breed generated using Chookjin-Duroc (KCD), Chookjin-Chamdon (KCC), and their crossbreds. Currently, there is a severe lack of studies investigating the Korean breed populations including wild boars (KWB) throughout the genome. Objective: This study was performed to investigate the genetic characteristics of Korean pig populations at the genome-wide level. Methods: Using the SNP dataset derived from genotyped and downloaded datasets using the Illumina PorcineSNP60K BeadChip, we compared the genomes of 532 individuals derived from 23 pig breeds to assess the genetic diversity, inbreeding coefficient, genetic differentiation, and population structure. Results: KWB showed the lowest average expected heterozygosity (HE = 0.1904), while KWH showed the highest genetic diversity (HE = 0.02859) among Korean populations. We verified that the genetic composition of KWH, showing USD of 74.8% and KCC of 25.2% in ADMIXTURE analysis. In population structure analyses, KCC was consistently shown to be separated from other pig populations. In addition, we observed gene flow from Western pigs to a part of Chinese populations. Conclusion: This study showed that Korean native pigs, KCC have genetic differences in comparison with Chinese and Western pigs; despite some historical records and recent genetic studies, we could not find any clear evidence that KCC was significantly influenced by Chinese or Western breeds in this study. We also verified the theoretical genomic composition of KWH at the molecular level in structure analyses. To our knowledge, this is the first genomic study to investigate the genomic characteristics of KWH and KCC.

Effects of the Ultrasound Treatment on Reaction Rates in the RH Processor Water Model System

Yong‑tae Kim,Kyung‑woo Yi 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1

Ruhrstahl–Heraeus (RH) processor is widely applied to the refining process to produce steel with very low carbon contents. In this study, to investigate the effect of ultrasound treatment on RH decarburization process, we have developed two kinds ofthe water models simulated the RH process and study the removal rate of dissolved oxygen. The one is the RH water modelof 1/8 size of actual RH degasser simulated the late-stage of the RH process when surface reaction and plume reaction mainlyoccur. Through this model, it is found that the ultrasound treatment accelerates dissolved oxygen removal reaction and thistendency is maintained even at low concentrations. Also, the results show that there is a difference in the degassing efficiencydepending on the frequencies and the positions of the ultrasonic transducer. Also, to simulate the Early-stage Reaction ofthe process including the inner-site reaction which is difficult to investigate through the RH water model, the other watermodel has been developed (the RH-ER water model). This model shows that the ultrasound treatment facilitates the earlystagereaction including inner-site reaction, like the RH water model. These results show that the addition of the ultrasoundtreatment can accelerate decarburization reaction during RH process compared to conventional process.

The 21st Century Christian Mission in Asian Universities

( Yong-woo Park ) 한국대학선교학회 2005 대학과 선교 Vol.8 No.-

We live in a global world. The development of transportation and communication has brought countries closer together and has created true 24 hour global village. The 21st century is totally different from the previous century in many ways of life. The emergence of knowledge industries such as IT, BT, and NT are changing ethical standards. The achievement of Professor Hwang Woo-suk``s stem cell study caught the world by surprise despite ethical issues. Nevertheless, no matter how much knowledge industries and science develops man is dependent on religion. This is because man does not know what happens tomorrow and is uncertain of the future. Also, an issue that pertains to the missionary work of a certain university may be a common issue faced by all universities in Asia. In this dissertation I laid out the challenge and necessity of religious education today as an introduction, the situations of religious freedom at schools in Korea, countries accepted religion as an official curriculum, Christian mission programs in various colleges and universities in Asia, and for the conclusion I suggested the desirable ways for the future and some proposals for the development of some Christian subjects and chapel programs to be used together in Asian colleges and universities.

Improvement of Desulfurization Efficiency via Numerical Simulation Analysis of Transport Phenomena of Kanbara Reactor Process

Yong‑Joon Lee,Kyung‑Woo Yi 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.4

The Kanbara reactor (KR) process is a mechanical stirring method that reacts hot metal with desulfurization flux; it is a widelyimplemented desulfurization method in contemporary steel production. This study aimed to develop a new impeller profilefor improving the desulfurization efficiency of the KR process. We implemented operational data analysis, a computationalfluid dynamics simulation based on the operational data and performed testing and analysis with impeller models on-site aproduction facility. Operational data from the production facility was gathered over a 3-year period. Seven impeller modelswith varying impeller blade width (top and bottom), height, inclination, and curvature (curved, straight, and combination)were simulated. The results were analyzed to determine the optimal conditions. A new impeller design was selected for onsiteoperational testing to investigate the in situ desulfurization efficiency over 350 charges, and the results corroborated thepredictions by the numerical simulations. It is expected that the proposed process modification can be successfully used forimproving industrial desulfurization efficiency.

항정신병약물 사용 중인 정신분열병 환자에서 올란자판으로의 교체 방법에 관한 연구(II) : Comparison of Safety 안전성 비교

안용민,권용실,권준수,민성호,박두병,양문정,소형석,송종호,신윤식,우행원,유범희,이홍석,정한용,한창환,김용식 大韓神經精神醫學會 2002 신경정신의학 Vol.41 No.5

연구목적: 이 다기관 공동임상연구는 사용 중인 항정신병약물을 ’직접 교체 방법’또는 ’시작-감량 교체 방법’중 한 가지 방법으로 올란자핀으로 교체한 후, 안정성 측면에서 두 교체 방법 간의 비교와 교체후의 변화를 관찰하기 위한 것이다. 방법: 국내 13개 병원의 입원 및 외래에 내원한 환자들 중 ICD-10 지단기준으로 정신분열병에 해당되며, 임상적으로 항정신병약물 교체가 필요한 환자를 대상으로 하였다. 두 가지 교체 방법 중 한 가지를 무작위로 피험자에 적용하였으며, ’직접 교체 방법’에 배정된 경우에는 사용중인 항정신병약물을 일시에 중단하고 10㎎의 올란자핀을 바로 투여하였고, ’시작-감량 교체 방법’에 배정된 경우는 10㎎의 올란자핀 투여하고 2주에 걸쳐서 기존 약물을 감량하여 중단하였다. 올란자핀 사용기간은 총 6주이며, 용량은 5∼20㎎ 범위로 제한하였다. 한정성 평가를 위해서 체중, 생명징후, 자발적인 이상반응 복, 실험실 검사 그리고 Simpson-Angus Scale(SAS), Barnes akathisia rating scale(BARS), Abnormal involuntary movement scale(AIMS). Liverpool University neuroleptic side effect rating scale(LUNSERS)등을 이용하였다. 결과: 총 103명의 정신분열병 환자를 대상으로 하였다. 사용한 올란자핀의 용량, 벤조디아제핀의 병용률, 탈락률과 탈락 사유, 자발적인 이상반응 보고, 생명징후, 실험실 검사 그리고 대부분의 부작용 척도 상에서 임상적으로 의미 있는 차이를 두 교체 방법간에 발견하지 못하였다. 다만 AIMS의 감소는 ’직접 교체 방법’군에서 보다 적었고, 항콜린제의 병용률은 ’시작-감량 교체 방법’군에서 보다 많았다. 기저 상태에서 전체 피험자의 SAS와 BARS 점수는 각각 3.5점과 1.8점이었으며 70% 이상의 피험자가 고프로락틴 혈증을 보였다. 올란자핀으로 교체한 후, SAS, BARS, AIMS 점수의 유의한 감소가 있었으며 고프로락틴 혈증을 보인 피험자 분율도 약 30%이하로 감소하였다. 그러나 교체 방법과 상관없이 올란자핀 교체 후 유의한 체중 증가가 있었다. 결론: 이 연구를 통해 교체 방법에 관계없이 비교적 안전하고 용이하게 올란자핀으로 교체 할 수 있음을 알 수 있었다. 그리고 기존 항정신병약물을 올란자핀으로 교체함으로써 일부 부작용들을 줄일 수 있음을 간접적으로 관찰할 수 있었다. 하지만 이 연구는 여러 제한점과 문제점을 지니고 있기 때문에 보다 체계적인 연구를 통해 검정이 필요하리라 생각된다. Objectives: This multicenter clinical trial involving 13 hospital sites compared the safely of switching to olanzapine between ’direct switching method’ and ’start-tapering switching method’. Method: This study included both inpatients and outpatients who fulfilled the criteria for schizophrenia as defined in the ICD-10, and were in need to be appropriate for switching antipsychotics. Subjects were randomly assigned to one of the two switching methods. For ’direct switching method’group, previous antipsychotics were abruptly discontinued and 10㎎ of olanzapine was administered, and previous antipsychotics was gradually tapered for 2 weeks. Olanzapine was used for 6 weeks and the dose was adjusted within the range of 5-20㎎. The safety of switching to olanzapine was measured with vital sings including body weight, adverse events reported spontaneously, laboratory tests, and various scales such as Simpson-Angus Scale(SAS), Barnes Akathisia Rating Scale(BARS). Abnormal Involuntary Movement Scale(AIMS), and Liverpool University Neuroleptic Side Effect Rating Scale(LUNSERS). Results: 103 patients were switched to olanzapine in this study. The comparison between two switching methods did not show any significant difference in the dosage of olanzapine used, the concomitant use of benzodiazepine, the rate and reasons of drop-out, the adverse events, vital signs, laboratory tests, and most scales for measuring side-effects. However, the decrease in AIMS scores was significantly lower in ’direct switching method’ group, and the concomitant use of anticholinergics was comparatively greater in ’start-tapering switching method’ group. At baseline, SAS and BARS scores were 3.5 and 1.8 points respectively, and more than 70% of the subjects showed hyperprolactinemia. After switching to olanzapine, SAS, BARS, and AIMS scores were significantly decreased and the proportion of the patients with hyperprolactinemia was also decreased to less than 30%. However significant weight gain after the treatment of olanzapine was observed regardless of switching method. Conclusion: This study may suggest that switching to olanzapine can be done with relatively high safety regardless of switching methods and olanzapine can significantly decrease some side-effects induced by other antipsychotics.

교사들의 공통과학 실험 · 실습 선호도 조사 분석

정원우,이윤종,강용희,윤일희,이우붕,손종경,김중욱,강동진,권용주 慶北大學校 師範大學 科學敎育硏究所 1999 科學敎育硏究誌 Vol.23 No.-

The purpose of this study is to investigate the status of the experimental and practical education in high school general science. The present status and reasonable management of the experimental and practical education in high school general science were evaluated by the questionaires. To do this, 146 science teachers in Korea are administered questionaires. The frequency of the experimental and practical items in the seven kind of general science text books were investigated. The problems and the reasonable management for experimental and practical education were proposed in this paper.

소아의 상완골 원위부 과간 골절

이우석,정환용,김우식,김용찬,전택수,김남현,김규태 대한골절학회 2004 대한골절학회지 Vol.17 No.4

상완골 원위부 과간 골절은 소아에서는 매우 드물게 발생되는 골절로 대부분 주관절의 굴곡상태로 주관절 후방부에 직접적인 충격에 의해 발생하는 것으로 보고되고 있다. 전위가 없거나 경미한 경우 도수적 정복술 혹은 도수적 정복술 후 경피적 핀고정술을 시행하며, 전위가 심한 골절이거나 도수적 정복술이 불가능한 경우 관혈적 정복술 후 핀고정술을 시행하는 것으로 알려져 있다. 저자들은 전위된 상완골 원위부 과간 골절 환아 2예에서 각각 도수적 정복술과 관혈적 정복술 후 K 강선 고정술을 시행하여 만족한 결과를 얻었기에 보고하는 바이다. Intercondylar fractures of the distal humerus are very rare in children. The pattern of the fracture would suggest that the mechanism of injury involves a fall directly on the flexed elbow. Most agree that the undisplaced fracture can be managed conservatively. With increasing displacement and comminution, the opinions tend to differ. We suggest that closed reduction with percutaneous K wire pinning and open reduction with percutaneous K wire pinning offer a satisfactory methods by which to treat displaced intercondylar fracture in children.

부산시 용호동 정책이주단지 주거공간의 내·외부 변용 특성에 관한 연구

김용운(Kim, Yong-Woon),유재우(You, Jae-Woo) 대한건축학회 2014 대한건축학회 학술발표대회 논문집 Vol.34 No.2

증폭원리를 이용한 초정밀 나노스테이지 개발

최수창,김용우,김진근,박정우,이득우 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

The laser-interferometer and capacitive displacement sensors were used to increase the resolution of the feedback system for stage used for measuring and processing the system. However, it was difficult to obtain high-resolution measurements, considering the measuring method and structural characteristics. This study developed a inverse magnification type stage to evaluate characteristics. Therefore, we introduced a nano-stage with a magnification mechanism for the position feedback system.