대규모 병렬기계 흐름생산의 재일정계획

정남기,유철수,김종민,최정길,Chung, Nam-Kee,Yoo, Chul-Soo,Kim, Jong-Min,Choi, Jeong-Gil 대한산업공학회 1996 산업공학 Vol.9 No.2

A scheduling system is developed for a parallel machine flow shop which reflects the situations of the manufacturing processes in the tire industry. The schedule is generated via simulation using heuristic rules to get satisfaction on such constraints as due dates, demands, work-in-process, process capacity, set-up times and scheduling speed. This system, constructed with relational DB, SQL and C language, consumes less than 10 minutes of PC simulation to handle real size problems.

SSD 수명 관점에서 리눅스 I/O 스택에 대한 실험적 분석

정남기(Nam Ki Jeong),한태희(Tae Hee Han) 대한전자공학회 2015 전자공학회논문지 Vol.52 No.9

낸드 플래시 기반의 SSD (Solid-State Drive)는 HDD (Hard Disk Drive) 대비 월등한 성능에도 불구하고 쓰기 회수 제한이라는 태생적 단점을 가지고 있다. 이로 인해 SSD의 수명은 워크로드에 의해 결정되어 SSD의 기술 변화 추세인 SLC (Single Level Cell) 에서 MLC (Multi Level Cell) 로의 전환, MLC에서 TLC (Triple Level Cell) 로의 전환에 있어 큰 도전이 될 수 있다. 기존 연구들은 주로 wear-leveling 또는 하드웨어 아키텍처 측면에서 SSD의 수명 개선을 다루었으나, 본 논문에서는 호스트가 요청한 쓰기에 대해 SSD가 낸드플래시 메모리를 통해 처리하는 수명관점의 효율성을 대변하는 WAF (Write Amplification Factor) 관점에서 Host I/O 스택 중 파일 시스템, I/O 스케줄러, 링크 전력에 대해 JEDEC 엔터프라이즈 워크로드를 이용해 I/O 스택 최적 구성에 대해 실험적 분석을 수행하였다. WAF는 SSD의 FTL의 효율성을 측정하는 지표로 수명관점에서 가장 객관적으로 사용한다. I/O 스택에 대한 수명 관점의 최적 구성은 MinPower-Dead-XFS로 최대 성능 조합인 MaxPower-Cfq-Ext4에 비해 성능은 13% 감소하였지만 수명은 2.6 배 연장됨을 확인하였다. 이는 I/O 스택의 최적화 구성에 있어, SSD 성능 관점뿐만 아니라 수명 관점의 고려에 대한 유의미를 입증한다. Although NAND flash-based SSD (Solid-State Drive) provides superior performance in comparison to HDD (Hard Disk Drive), it has a major drawback in write endurance. As a result, the lifetime of SSD is determined by the workload and thus it becomes a big challenge in current technology trend of such as the shifting from SLC (Single Level Cell) to MLC (Multi Level cell) and even TLC (Triple Level Cell). Most previous studies have dealt with wear-leveling or improving SSD lifetime regarding hardware architecture. In this paper, we propose the optimal configuration of host I/O stack focusing on file system, I/O scheduler, and link power management using JEDEC enterprise workloads in terms of WAF (Write Amplification Factor) which represents the efficiency perspective of SSD life time especially for host write processing into flash memory. Experimental analysis shows that the optimum configuration of I/O stack for the perspective of SSD lifetime is MinPower-Dead-XFS which prolongs the lifetime of SSD approximately 2.6 times in comparison with MaxPower-Cfq-Ext4, the best performance combination. Though the performance was reduced by 13%, this contributions demonstrates a considerable aspect of SSD lifetime in relation to I/O stack optimization.

KOMPSAT-2/3/3A호의 영상융합에 대한 품질평가 프로토콜의 비교분석

정남기 ( Nam-ki Jeong ),정형섭 ( Hyung-sup Jung ),오관영 ( Kwan-young Oh ),박숭환 ( Sung-hwan Park ),이승찬 ( Seung-chan Lee ) 대한원격탐사학회 2016 大韓遠隔探査學會誌 Vol.32 No.5

Many image fusion quality assessment techniques, which include Wald`s, QNR and Khan`s protocols, have been proposed. A total procedure for the quality assessment has been defined as the quality assessment protocol. In this paper, we compared the performance of the three protocols using KOMPSAT- 2/3/3A satellite images, and tested the applicability to the fusion quality assessment of the KOMPSAT satellite images. In addition, we compared and analyzed the strengths and weaknesses of the three protocols. We carried out the qualitative and quantitative analysis of the protocols by applying five fusion methods to the KOMPSAT test images. Then we compared the quantitative and qualitative results of the protocols from the aspects of the spectral and spatial preservations. In the Wald`s protocol, the results from the qualitative and quantitative analysis were almost matched. However, the Wald`s protocol had the limitations 1) that it is timeconsuming due to downsampling process and 2) that the fusion quality assessment are performed by using downsampled fusion image. The QNR protocol had an advantage that it utilizes an original image without downsampling. However, it could not find the aliasing effect of the wavelet-fused images in the spectral preservation. It means that the spectral preservation assessment of the QNR protocol might not be perfect. In the Khan`s protocol, the qualitative and quantitative analysis of the spectral preservation was not matched in the wavelet fusion. This is because the fusion results were changed in the downsampling process of the fused images. Nevertheless, the Khan`s protocol were superior to Wald`s and QNR protocols in the spatial preservation.

한국인 산모에서 B형 간염 바이러스의 보유율 변화에 관한 연구

오은아 ( O Eun A ),정숙애 ( Jeong Sug Ae ),정만 ( Jeong Man ),심승식 ( Sim Seung Sig ),양인애 ( Yang In Ae ),최관수 ( Choe Gwan Su ),정남기 ( Jeong Nam Gi ) 대한내과학회 1990 대한내과학회지 Vol.38 No.6

N/A In an attempt to investigate the yearly changes of the HBsAg carrier rate by observing the HBsAg positive rate in full-term pregnant women who are definitely related to the vertical transmission of the hepatitis B virus, as well as to analyze the epidemiologic factors which influence the HBsAg positive rate in pregnant women, we tested HBsAg and checked the histories of about 20 epidemiologic factors in 10,359 prgnant women .who delivered at St. Columban`s Hospital in Mokpo City from April 1, 1985 to June 30, 1989. The results were as follows: 1) Overall HBsAg positivity in all 10,359 pregnant women was 7.9%. 2) The positive rate of HBsAg was unrelated to the frequency or degree of alcohol drinking,smoking, income, nutritional state, hygiene, education, religion, occupation, locality or, injections at home in pregnant women. 3) The positive rates of HBsAg were higher in cases who had acupuncture, venereal disease, who had more than four siblings, and who worked as an institutional worker or hospital staff. The positive rates of HBsAg increased significantly in cases who had blood transfusions(0.025<p<0.05), who had injections at hospitals(p<0.005), who had no hepatitis B vaccination(p<0.005), who had a family history of liver disease(p<0.001) and who were much older(p<0.005). 4) The positive rate of HBsAg was decreased significantly from 9.2% to 7.0% for five years(p<0.001). There were several factors which influence the HBsAg positivity every year. First, the rate of hepatitis B vaccination increased significantly(p<0.001), second, the number of pregnant women who had more than six siblings increased significantly(0.025<p<0.05) and third, the number of pregnant women who had acupuncture decreased significantly(p<0.001). But the number of pregnant women who were over 30 years old increased significantly(p<0.001). 5) The positive rate of HBsAg increased significantly from 7.2% to 13.0% as the age increased(p<0.005). There were several factors which influenced HBsAg positivity by age group. Although the rate of hepatitis B vaccination increased significantly in the older age groups(p<0.001), the positive rate of HBsAg increased more in the older age groups because the numbers of pregnant women who had acupuncture(p<0.001) and a family history of liver disease(p<0.005) increased significantly. The results suggest that the number of HBV carrier pregnant women in Korea decreased progressively every year. Although the rate of hepatitis B vaccination increased significantly, it was not so effective due to the small total number. The number of pregnant women who had acupuncture and a family history of liver disease increased significantly, especially those over 30 years old. So it is important to have a nationwide program of hepatitis B immunization and to educate people on how to interfere with the transmission route in order to eradicate hepatitis B in Korea.

TOC 와 6 시그마의 협력 방안

정남기(Nam Kee Chung),정문기(Moon Ki Jeong) 한국품질경영학회 2001 품질혁신 Vol.2 No.1

6시그마 품질경영 활동은 고객관점에서 품질의 결함을 찾고 이를 향상시킴으로써 고객만족과 수익향상에 큰 기여를 한 것이 사실이다. 그렇지만 품질개선 활동을 확장하여 경영전략으로 발전시키는 데에는 몇가지 문제점들이 지적되고 있다. 경영성과 척도로서 시그마 수준을 일률적으로 적용하는 것이 그 예이다. TOC(Theory of Constraints)는 시스템 사고에 의한 경영전략을 제시하는 이론이다. 이 논문은 TOC의 관점에서 6시그마의 한계를 조명하고, TOC와 6시그마의 상호협력방안을 모색해 본다.

응용논문 / ISO 9000 품질시스템에서 형상관리의 구현에 관한 연구

정남기(Nam Kee Chung),최정길(Jeong Gil Choi),김영식(Young Sik Kim),박상규(Sang Kyu Park),김재전(Jae Jon Kim),황부현(Bu Hyun Hwang) 한국품질경영학회 2000 품질경영학회지 Vol.28 No.2

FOCUS - 멀티스케일 구조를 갖는 저비용·고성능 연료전지 촉매

유성종,정남기,Yu, Seong-Jong,Jeong, Nam-Gi 한국과학기술단체총연합회 2014 과학과 기술 Vol.545 No.-

NIR 관련 논문 통계 분석에 의한 NIR 원격탐사의 기술 및 활용분야 고찰

백원경,박숭환,정남기,권수경,진원지,정형섭,Baek, Won-Kyung,Park, Sung-Hwan,Jeong, Nam-Ki,Kwon, Sookyung,Jin, Won-Ji,Jung, Hyung-Sup 대한원격탐사학회 2017 大韓遠隔探査學會誌 Vol.33 No.5

본 연구에서는 NIR(Near-Infrared) 원격탐사 자료를 이용한 연구의 결과인 논문을 분석함으로써 NIR의 기술 및 활용 연구 분야를 체계적으로 정리하고, 이후 NIR 영상을 활용한 연구의 흐름과 방향을 정립하는 데에 목표가 있다. 이를 위하여 최근 5년간의 국내 저널들과 활용 분야 SCI저널, 기술 개발 분야 SCI저널에 대하여 NIR 활용 연구에 관하여 사례조사를 실시하였다. 선별작업 이후 총 281편의 논문에 대하여 분석을 수행하였으며 통계 분석을 위해 분류와 소분류로 구분하여 우세한 연구 추세를 살펴보았다. 그 결과 논문 작성을 수행한 연구자들의 소속은 대학이 약 60% 이상으로 가장 높았다. 적용 분야의 경우 국외에서 육지 50%, 환경 30% 그리고 재해 11%의 분포를 나타냈다. 한편 국내의 경우 육지 55%, 환경 24%, 재해 10%의 분포를 보였다. 육지에 대한 국내 연구 사례는 임업과 농업이 각각 47%, 28%로 가장 높은 비율을 차지했다. 그 외에 국토관리(17%), 지질/자원과 관련하여 나머지 8%를 차지했다. NIR을 활용한 재해 관측은 산사태, 가뭄, 기상재해, 홍수 등에 활용되었다. 여기서 특히 기상재해는 황사에 관한 연구 결과로 국내의 실정이 반영된 것으로 보인다. 하지만 국내의 연구 사례 중 산불 탐지에 관한 결과가 존재하지 않았다. 국내의 실정을 고려해 볼 때에 이에 관한 추가적이고 활발한 연구가 수행될 필요가 있어 보인다. 이 통계적 논문 분석 자료가 향후 우리나라의 NIR 기술 개발과 활용 분야 확장에 도움이 될 기초 자료로 활용될 수 있기를 기대한다. In this study, we analyzed the paper about NIR (Near-Infrared) remote sensing data and systematically summarized the research and application fields of NIR. To do this, we conducted a case study on the use of NIR in domestic journals, and SCI journals in the field of technology development for the last 5 years. After selection, a total of 281 journals were analyzed. For the statistical analysis, the classification was divided into subclasses and the dominant research trends were examined. As a result, the researchers who wrote the papers made the highest score of about 60% or more at university. In the field of application, 50% of land, 30% of environment, and 11% of disaster were distributed on SCI journals. In Korea, on the other hand, 55% of land, 24% of environment and 10% of disasters were distributed. In addition, 17% of the national land management and 8% of the geological / natural resources. Disaster observation using NIR was used for landslide, drought, weather disaster and flood. In particular, meteorological disasters are a result of study on Asian dust. However, there were no results of forest fire detection in Korea. Considering the domestic situation, it seems necessary to carry out additional and active research on this. It is expected that this statistical analysis data will be used as basic data to help expand the NIR technology development and utilization field in Korea in the future.

아리랑 2호/3호 영상을 이용한 영상융합 비교 분석

오관영(Oh, Kwan Young),정형섭(Jung, Hyung Sup),정남기(Jeong, Nam Ki),이광재(Lee, Kwang Jae) 한국측량학회 2014 한국측량학회지 Vol.32 No.2

간장 및 담도 : 산모와 신생아에서 B 형 간염표식자에 (肝炎標識子) 관한 연구

박광숙(Kwang Sook Park),최관수(Gwan Su Choi),정원재(Won Jae Jeong),김지운(Ji Woon Kim),정남기(nam Ki Joung),장영호(Yung Ho Chang) 대한소화기학회 1986 대한소화기학회지 Vol.18 No.1

N/A To analyze frequency and severity of liver disease in 3rd trimester and full term Korean pregnant women, to observe the prevalence of HBV markers in pregnant women and newborn infants at delivery and to evaluate the effect of HBV on fetus, newborn infants and pregnant women. We received the findings of the physical examination and history taking, and did SGPT and HBV markers with EIA method at intervals in 2,873 pregnant women who delivered at St. Columbans Hospital in Mokpo City from April 1st, 1985 to March 31st, 1986. The following results were obtained: 1) The overall HBsAg positivity in all 2,873 pregnant women was 8.3% 2) Among 2,873 pregnant women, 5 cases in 3rd trimester and 6 cases in full-term pregnant women showed typical acute viral hepatitis B and most of them were normal in their follow-up tests. 32 cases who shoWed mild elevation of SGPT were normal in their follow-up tests. But it was difficult to differentiate between a course of acute or chronic hepatitis and mild liver dysfunctions during pregnancy. 3) Among 195 HBsAg positive pregnant women, 76 cases(39.0%) were HBeAg positive, 65 cases(33.3%) were HBeAg negative and 54 cases(27.7%) were Anti-HBe positive. 4) Mother to infant transmission of HBV markers at delivery was as follows: Positive rate of HBsAg was 10.0% or 14 infants in 140 pregnant women. Positive rate of HBeAg was 17.8% or 8 infants in 45 cases. Positive rate of anti-HBs was 88.9% or 16 infants in 18 cases. Positive rate of anti-HBc was 96.2% or 125 infants in 135 cases. Positive rate of anti-HBe was 100% or 35 infants in 35 cases. 5)We evaluated the HBV markers in newborn infants 3 groups according to the maternal HBeAg/Anti-HBe status at delivery in 107 HBsAg positive pregnant women. Out of 38 HBeAg positive women, 6 infants(15.8%) were positive for HBsAg and HBeAg, 31 infants (81.6%) were negative for HBsAg, HBeAg and anti-HBe. Out of 39 HBeAg reative women, 2 infants(5.1%) were positive for HBsAg and negative for HBeAg, 31 infants(79.5%) were negative for HBsAg, HBeAg and anti-HBe. Out of 30 anti-HBe positive women, 3 infants (10.0%) were positive for HBsAg and anti-HBe, negative for HBeAg, 22 infants(73.3%) were negative for HBsAg and HBeAg, positive for anti-HBe. HBV markers in newborn infants corresponded to their mothers degree of infection. 6) Among 2,873 pregnant women, vve found 135 cases of prematurity, 6 cases of still birth cases of intrauterine death, 56 cases of congenital anomaly and 122 cases of severe physiologic jaundice. We also found in the past history 75 cases of prematurity, 18 cases of stillbirth, 36 cases of intrauterine death, 14 cases of congenital anoma!y, 34 cases of infantile death and 444 cases of spontaneous abortion. There was no significant incrcase in frequency of adverse effects of HBV according to the mothers HBsAg positivity status. 7) Positive rate of HBsAg was 16.4% in 61 cases who showed toxemia of pregnancy. Positive rate of HBsAg was 8.1%. In 2, 812 cases who showed no toxemia of pregnancy. There was significant increase of toxemia of pregnancy in HBsAg carrier(0.01<P<0.025). Positive rate of HBsAg was 14.7% in 109 cases who bled more than 500 cc postpartum hemorrhage. Positive rate of HBsAg was 8.1% in 2812 cases who bled less than 500cc postpartum hemorrhage. There was significant increase of postpartum hemorrhage in HBsAg carrier(0.01<p<0.005). Severity of hyperemesis was unrelated to HBsAg positivity. 8) We observed the course and severity of hepatitis during pregnancy. Among 5 cases in 3rd trimester and 6 cases in full term pregnant women, only one case showed elevation of SGPT for more than 6 months. Among 19 non-pregnant women, one case in 15 patients of acute viral hepatitis and 3 cases in 4 patients of chronic viral hepatitis showed elevation of SGPT for more than 6 months. There was no significant difference in couse, severity and prevalence of HBV markers between pregnant and non-pregnant women.