네트워크 코딩의 병렬처리 성능비교

최성민,박준상,안상현,Choi, Seong-Min,Park, Joon-Sang,Ahn, Sang-Hyun 한국정보처리학회 2012 정보처리학회논문지 C : 정보통신,정보보안 Vol.19 No.4

네트워크 코딩(Network Coding)은 통신망의 성능 향상에 도움을 줄 수 있으나 이의 소프트웨어적 구현은 부호화/복호화 단계에서 매우 큰 지연시간을 유발할 수 있어 이를 줄일 수 있는 병렬화된 구현이 필수적이라 할 수 있다. 본 논문에서는 랜덤 리니어 네트워크 코딩(Random Linear Network Coding)과 랜덤 리니어 네트워크 코딩의 단점을 보완하고자 최근 제안된 파이프라인 네트워크 코딩(Pipeline Network Coding)의 병렬처리 성능을 비교한다. 또한, 네트워크 코딩의 CPU에서의 병렬처리 기법과 GPGPU(General Purpose Graphics Processing Units)에서의 병렬처리 기법을 비교하여 네트워크 코딩의 사용 시 그 파라미터에 따라 적절한 병렬처리 기법을 선택할 필요성이 있음을 보여준다. Network coding has been shown to improve various performance metrics in network systems. However, if network coding is implemented as software a huge time delay may be incurred at encoding/decoding stage so it is imperative for network coding to be parallelized to reduce time delay when encoding/decoding. In this paper, we compare the performance of parallelized decoders for random linear network coding (RLC) and pipeline network coding (PNC), a recent development in order to alleviate problems of RLC. We also compare multi-threaded algorithms on multi-core CPUs and massively parallelized algorithms on GPGPU for PNC/RLC.

치과용 지르코니아 블럭의 착색시간에 따른 색조변화 관찰

최성민,남상용,Choi, Sung-Min,Nam, Sang-Yong 대한치과기공학회 2011 대한치과기공학회지 Vol.33 No.3

Purpose: The current study focused on investigating color change of dental zirconia block with respect to the block coloring time. Methods: Three types of dental zirconia blocks(Zirtooth, Pearl-HT, D-Max) were tinted with coloring agent under four different time condition (0 minutes, 1 minutes, 10 minutes, 30 minutes). The quantitative evaluation of the tinted dental zirconia blocks was conducted with spectrophotometer. Results: The Zirtooth and D-Max blocks showed lower H value. The Pearl-HT blocks showed poor reflectivity(L value). Conclusion: The study of color change of zirconia block, which consists the substructure of all ceramic Crown, is applicable for deciding appropriate coloring condition when fabricating one layer ceramic Crown or double layer ceramic Crown.

나노구조 분석을 위한 하나로 40m 소각중성자산란장치 개발

최성민,김태환,이지환,한영수,이창희,Choi Sung-Min,Kim Tae-Hwan,Lee Ji-Hwan,Han Young-Soo,Lee Chang-Hee 한국진공학회 2005 Applied Science and Convergence Technology Vol.14 No.3

소각중성자산란 (Small-angle neutron scattering, SANS)은 물질의 내부 나노구조 분석에 매우 중요한 실험방법론이다. 본 논문에서는 30MW HANARO 연구용 원자로의 냉중성자 연구시설에 설치하기 위하여 한국과학기술원과 한국원자력연구소가 공동으로 개발 중인 40m SANS장치의 개념설계 결과를 보고한다. 장치의 설계 최적화를 위한 전산모사를 수행하였으며, 이를 바탕으로 40m SANS 장치의 주요설계 인자를 결정하였다. 40m SANS 장치의 가능한 Q-range는 $0.0005\;\AA^{-1}-1.0\AA^{-1}$ 이며, 이는 세계 최고 수준의 SANS Q-range에 해당된다. 각 Q-range에 따른 시료위치에서의 중성자 속을 계산하였으며 전산모사에 사용된 냉중성자원이 구현될 시 세계적 수준의 값을 얻을 수 있을 것으로 예상된다. Small-angle neutron scattering (SANS) is a very powerful techniques for nanostructure characterization. In this paper, we report the conceptual design and technical description of the 40 in small angle neutron scattering (SANS) insoument which is being developed by KAIST and KAERI for installation at 30 MW HANARO research reactor. For the optimal design of 40 m SANS, a series of computer simulation were pe.to.mod. The Q-.ange of the 40m SANS inst.ument is $0.0005\;\AA^{-1}-1.0\AA^{-1}$ which is a world top-class SANS Q-range. When the cold neutron spectrum used in the simulation is realized, the neutron flux at sample position is expected to be comparable to the current state-of-art SANS instrument in the world.

수열법으로 성장한 ZnO Nanorod/ZnO/Si(100)의 특성

정민호,진용식,최성민,한덕동,최대규,Jeong, Min-Ho,Jin, Yong-Sik,Choi, Sung-Min,Han, Duk-Dong,Choi, Dae-Kue 한국재료학회 2012 한국재료학회지 Vol.22 No.4

Nanostructures of ZnO, such as nanowires, nanorods, nanorings, and nanobelts have been actively studied and applied in electronic or optical devices owing to the increased surface to volume ratio and quantum confinement that they provide. ZnO seed layer (about 40 nm thick) was deposited on Si(100) substrate by RF magnetron sputtering with power of 60 W for 5 min. ZnO nanorods were grown on ZnO seed layer/Si(100) substrate at $95^{\circ}C$ for 5 hr by hydrothermal method with concentrations of $Zn(NO_3)_2{\cdot}6H_2O$ [ZNH] and $(CH_2)_6N_4$ [HMT] precursors ranging from 0.02M to 0.1M. We observed the microstructure, crystal structure, and photoluminescence of the nanorods. The ZnO nanorods grew with hexahedron shape to the c-axis at (002), and increased their diameter and length with the increase of precursor concentration. In 0.06 M and 0.08 M precursors, the mean aspect ratio values of ZnO nanorods were 6.8 and 6.5; also, ZnO nanorods had good crystal quality. Near band edge emission (NBE) and a deep level emission (DLE) were observed in all ZnO nanorod samples. The highest peak of NBE and the lower DLE appeared in 0.06 M precursor; however, the highest peak of DLE and the lower peak of NBE appeared in the 0.02 M precursor. It is possible to explain these phenomena as results of the better crystal quality and homogeneous shape of the nanorods in the precursor solution of 0.06 M, and as resulting from the bed crystal quality and the formation of Zn vacancies in the nanorods due to the lack of $Zn^{++}$ in the 0.02 M precursor.

한국 아동의 수면시간과 체질량지수

최성민(Sung-Min Choi),서완석(Wan-Seok Seo),성형모(Hyung-Mo Sung),구본훈(Bon-Hoon Koo),김경근(Kyung-Keun Kim),김소연(So-Yeun Kim),최소정(So-Jeong Choi),이종훈(Jong-Hun Lee) 대한소아청소년정신의학회 2009 소아청소년정신의학 Vol.20 No.3

Objectives:We conducted this study to investigate the relationship between sleep duration and body mass index (BMI), in Korean children. Methods:We performed a cross-sectional analysis of data collected on 3,639 boys and girls (aged 7-12) in Daegu, Korea. The data included each child’s age, sex, weight, height, extracurricular activities, bedtime, wake-up time, sleep latency, total sleep duration, parents’ occupations, and parents’ educational levels. The relationship between sleep duration and each variable was examined via analysis of variance (ANOVA). Results:The analysis showed an association between short sleep duration and high BMI. Boys showed a graded inverse relationship between sleep duration and BMI. However, there was no significant corresponding result for girls. In the total sample, hours of computer use, time when the computer was turned off, time when the television was turned off, mother’s bedtime, and hours of extracurricular activity were associated with longer sleep duration. No association was found between sleep duration and hours of watching television, child’s wake-up time, or educational level of the parents. Conclusion:The results of this study show an inverse relationship between a child’s sleep duration and BMI;thus, children with shorter sleep duration tend to have higher BMIs.

한국 제다의 전승 및 제다 문화재 지정에 관한 인문학적 고찰

최성민(Sung min Choi) 국제차문화학회 2016 차문화ㆍ산업학 Vol.34 No.-

병원의료종사자들의 환자안전문화 인식

최성민 ( Sung Min Choi ),이경란 ( Gyeong Ran Lee ),이미진 ( Mi Jin Lee ),김은미 ( Eun Mi Kim ),박형숙 ( Hyoung Sook Park ) 부산대학교 간호과학연구소 2016 글로벌 건강과 간호 Vol.6 No.1

Purpose: In this descriptive study, we determined the perceptions of patient safety culture among health professionals, including nurses, doctors, medical technicians, and hospital administrative staff. Methods: A questionnaire survey was used to collect data; specifically, we distributed questionnaires to 317 health professionals working for P National University Hospital in B Metropolitan city and P National University Hospital in Y City. The mean and standard deviations of the degree of awareness of patient safety culture were analyzed using t-tests and ANOVAs. Post-hoc comparisons were made with Scheffe``s test. Results: The mean score for perception of patient safety culture among study subjects was 3.43 out of 5, indicating that it was in the average range. When analyzing by position, nurses, medical technicians, and administrative staff tended to have better perceptions of patient safety culture than did doctors (F=22.13, p<.001). Furthermore, perceptions among health professionals appeared to vary by their age, education level, years of working in the current hospital, weekly work hours, work unit, attendance of safety education in the past year, number of patient safety education sessions attended in the past year, and awareness of the importance of accurate reporting procedures for safety accidents. Conculsion: As this study confirms, medical professionals’ prior experience with patient safety education, number of training sessions attended, and awareness of the reporting procedures for safety accidents influence their perceptions of the patient safety culture. Therefore, patient safety education should be promoted in line with the characteristics of each occupation. Additionally, it is recommended that cultures encouraging health professionals to actively attend the necessary training be established in hospitals.

Development of Hybrid-FDM Process Using Automatic Tool Changer for Multi-Material Production and Post-Processing

최성민(Sung Min Choi),샤오젠(XiaoJian),박인백(In Baek Park),이석희(Seok Hee Lee) Korean Society for Precision Engineering 2016 한국정밀공학회지 Vol.33 No.3

국소온열치료용 듀플렉스 스테인리스 스틸 발열체에 의한 혈관세포와 골세포의 온도에 따른 성장률 변화 관찰

최성민(Sung-Min Choi),김영곤(Young-Kun Kim) 한국콘텐츠학회 2009 한국콘텐츠학회논문지 Vol.9 No.11

본 연구는 국소온열요법(Local Hyperthermia)에 사용되는 발열체(Thermo-rod)의 온도에 따른 세포성장률의 변화를 관찰하고자 한다. 연구에 사용된 발열체는 듀플렉스 스테인리스 강(Duplex Stainless Steel)을 이용하여 개발되었다. 세포성장률을 관찰하기 위하여 CPAE세포와 Osteoblast세포를 이용하였다. 각각의 세포를 well에 분주 후 3일, 6일, 9일, 12일, 15일 동안 배양만 한 군을 대조군으로 하고 well에 발열체를 식립 후 세포를 분주하여 3일 간격(3일, 6일, 9일, 12일, 15일)으로 하루 30분 유도가열을 실시하여 15일 간 배양한 군을 시험군으로 하였다. CPAE세포와 Osteoblast세포의 성장률을 관찰한 결과 두세포 모두 3일의 대조군과 시험군 모두 세포 성장률이 급격이 상승하다 6일의 대조군과 시험군 모두 급격히 감소하고 9일과 12일 그리고 15일의 대조군과 시험군의 성장률은 불규칙하게 감소하였다. 이러한 성장률 관찰 결과 두종의 세포 모두 약 41℃의 온도를 가한 시험군과 온도를 가하지 않은 대조군의 차이가 없다. 따라서 CPAE세포와 Osteoblast세포는 발열체에 의한 온도(약 41℃)에 영향이 없는 것으로 판단된다. We investigated the cell growth rate according to the change of temperature of the Thermo-rod used for the local hyperthermia therapy. For this study, we fabricated the Thermo-rods (TR) using Duplex Stainless Steels having magnetic properties as well as non magnetic properties. To evaluate cell growth rates up to 15 days, we conducted cell proliferation test using cell counting methods. For the tests. the CAPEs and Osteoblats were seeded on the 6-well plates with the induction heated thermo-rods 30 mins a day for 15 days with 2 days interval and without induction heated thermo-rods as control group respectively. We calculated cell growth rates, 6 hours after heating. From the results, in case of CAPEs and Osteobalsts seeded groups, the cell growth rates in all groups increased drastically for 6 days after seeding, but decreased irregularly after 6 days. In conclusion, the cell growth rates showed no significant difference among all groups ,and it indicated that there were no effects of temperate (41℃) on cell growth rates.

기억의 종말로서의 죽음 판타지 -이연주 논(論)-

최성민 ( Choi Sung-min ),김장원 ( Kim Jang-won ) 한국문학치료학회 2016 문학치료연구 Vol.41 No.-

시를 특정한 역사적 상황과 관련지어 읽어낸다는 것은 문학이라는 것이 만들어내는 가능세계와 감각으로 체험할 수 있는 현실세계라는 두 가지 이질적 세계를 중첩시켜 파악한다는 것이다. 시 텍스트에 드러난 세계와 역사적·정치적 세계를 포개어놓고 독해함으로써 텍스트가 발산해내는, 혹은 담고 있는 두 가지 의미망을 모두 잡아내려하는 시도이다. 이연주는 1990년대 초반, 아주 짧은 기간 활동했던 시인이다. 1980년대의 뜨거움과 1990년대 말의 암울함에 묻혀 주목받지 못했거나, `신세대` 담론에 의해 경제적 호황과 더불어 진행된 대중문화의 부흥기 정도로 기억되는 이 시대가 실상은 매우 암울한 환멸이 가득 찼던 시대였음을 그 시대와 함께 종말을 맞이했던 이연주의 시가 숨죽여 노래하고 있다. 이연주의 시들에서는 사회적 가치의 붕괴나 사회적·정치적 문제를 개인적인 이야기나 가족의 이야기로 환원되어 드러남으로써, 사회적 담론에 대한 정신분석학적 접근이 가능하도록 하고 있다. 이연주의 시 텍스트에 등장하는 주체들은 가장 극단적인 고통과 좌절, 절망을 겪은, 혹은 겪고 있는 나약한 개인들이다. 이들의 고통은 사회적 상황이 그들에게 강요한 것이었으며, 시간이 흐르면 해결되는 것이 아니라 보다 큰 정신적 상처로 `기억` 속에 스며들게 될 것이었다. 이연주의 시는 이 시대의 암울함을 속죄양처럼 끌어안고 있던 텍스트였다. 디스토피아적 세계관과 환멸적 시선, 날것이나 다름없는 `몸`의 언어 표현력은 이연주의 시를 여타의 시들과 차별화할 수 있는 지점들이며, 재평가가 필요한 이유이다. We live in the actual world that we can experience with our senses. Literature shows the possible world. The meaning of a poem is generated by the gap between the possible world and the actual world. By comparing the world that exists in a text with the real world, the meaning of the text is shown more clearly. Lee Yeonju is a poet of the early 1990s. The early 1990s saw the Korean Renaissance of mass culture. Seotaiji is an icon of 1990s mass culture. The early 1990s sat between the heat of the 1980s and a fin-de-siecle mood. Lee Yeonju kept a cool voice to sing those times, filled with gloominess and disillusionment. Lee Yeonju`s poems place the shocking collapse of social value and political philosophy into individual stories. This makes psychoanalysis of social discourse possible. Lee Yeonju`s protagonists are vulnerable and have gone through extremely painful experiences. Those experiences result from social conditions and leave individual traumas. As time goes by, the pain does not disappear, but penetrates memories. Lee Yeonju`s poems sing the gloominess of the time by being scapegoats in and of themselves. She showed an excellent ability to express dystopian and disillusioning perspective bluntly. The time has come to reevaluate Lee Yeonju`s poems.