The advent of big data has brought about the need for analytics. Natural language processing (NLP), a field of big data, has received a lot of attention. Topic modeling among NLP is widely applied to identify key topics in various academic journals. The Korean Society of Industrial and Systems Engineering (KSIE) has published academic journals since 1978. To enhance its status, it is imperative to recognize the diversity of research domains. We have already discovered eight major research topics for papers published by KSIE from 1978 to 1999. As a follow-up study, we aim to identify major topics of research papers published in KSIE from 2000 to 2022. We performed topic modeling on 1,742 research papers during this period by using LDA and BERTopic which has recently attracted attention. BERTopic outperformed LDA by providing a set of coherent topic keywords that can effectively distinguish 36 topics found out this study. In terms of visualization techniques, pyLDAvis presented better two-dimensional scatter plots for the intertopic distance map than BERTopic. However, BERTopic provided much more diverse visualization methods to explore the relevance of 36 topics. BERTopic was also able to classify hot and cold topics by presenting ‘topic over time’ graphs that can identify topic trends over time.

Most of real-world decision-making processes are used to optimize problems with many objectives of conflicting. Since the betterment of some objectives requires the sacrifice of other objectives, different objectives may not be optimized simultaneously. Consequently, Pareto solution can be considered as candidates of a solution with respect to a multi-objective optimization (MOP). Such problem involves two main procedures: finding Pareto solutions and choosing one solution among them. So-called multi-objective genetic algorithms have been proved to be effective for finding many Pareto solutions. In this study, we suggest a fitness evaluation method based on the achievement level up to the target value to improve the solution search performance by the multi-objective genetic algorithm. Using numerical examples and benchmark problems, we compare the proposed method, which considers the achievement level, with conventional Pareto ranking methods. Based on the comparison, it is verified that the proposed method can generate a highly convergent and diverse solution set. Most of the existing multi-objective genetic algorithms mainly focus on finding solutions, however the ultimate aim of MOP is not to find the entire set of Pareto solutions, but to choose one solution among many obtained solutions. We further propose an interactive decision-making process based on a visualized trade-off analysis that incorporates the satisfaction of the decision maker. The findings of the study will serve as a reference to build a multi-objective decision-making support system.

Topic modeling has been receiving much attention in academic disciplines in recent years. Topic modeling is one of the applications in machine learning and natural language processing. It is a statistical modeling procedure to discover topics in the collection of documents. Recently, there have been many attempts to find out topics in diverse fields of academic research. Although the first Department of Industrial Engineering (I.E.) was established in Hanyang university in 1958, Korean Institute of Industrial Engineers (KIIE) which is truly the most academic society was first founded to contribute to research for I.E. and promote industrial techniques in 1974. Korean Society of Industrial and Systems Engineering (KSIE) was established four years later. However, the research topics for KSIE journal have not been deeply examined up until now. Using topic modeling algorithms, we cautiously aim to detect the research topics of KSIE journal for the first half of the society history, from 1978 to 1999. We made use of titles and abstracts in research papers to find out topics in KSIE journal by conducting four algorithms, LSA, HDP, LDA, and LDA Mallet. Topic analysis results obtained by the algorithms were compared. We tried to show the whole procedure of topic analysis in detail for further practical use in future. We employed visualization techniques by using analysis result obtained from LDA. As a result of thorough analysis of topic modeling, eight major research topics were discovered including Production/Logistics/Inventory, Reliability, Quality, Probability/Statistics, Management Engineering/Industry, Engineering Economy, Human Factor/Safety/Computer/Information Technology, and Heuristics/Optimization.

Companies struggle to make their best products with high quality and service at a competitive price in global markets. However, customer needs and requirements keep changing with a variety of situations. Companies that face the changes can not stay the same and make an effort to adapt themselves to new circumstances. They would probably review the overall management system that is currently implementing to improve management efficiency. Among other things, quality might be considered to be a crucial element if they are manufacturing industries to be sustained in global markets. KSA (Korean Standards Association) is a government- affiliated organization under the Ministry of Trade, Infrastructure, and Energy. It is a Korean standards provider for quality and service industry. KSA confers national commendations for organizations, quality circles, artisans, QCEC (Quality Competitive Excellent Company), and the most honorable KNQA (Korean National Quality Award) every year. KSA established KNQA on the basis of Malcom Baldrige National Quality Award, Deming Prize, and European Quality Award. Research on quality awards shows that there are many similarities in the framework. Although KSA summarizes two factors for 13 evaluation indicators in the quality competitive excellent model of QCEC, the categorization is ambiguous to explain them according to earlier studies. We performed a deep analysis of foreign quality awards and background for KNQA and QCEC. We conducted a content analysis of KNQA and QCEC and matched evaluation items that were closely related. We proposed a quality competitiveness model with three factors, Technology, System, and Tools, summarizing 13 evaluation indicators in QCEC. Based on audit data for six years from 2012 to 2017 we carried out a confirmatory factor analysis for the proposed model by examining the model validity and fitness.

Quality management has become an pervasive philosophy in most sectors of business. Specific movements such as statistical quality control, quality circle, total quality management, and quality management system have become embedded in business organizations. Only the companies with competitive edge can survive in the competition in global market. KSA(Korean Standards Association) established in 1962 has launched all kinds of quality education, quality standard certification service for business, and KNQA(Korean National Quality Award) system. This article considers quality competitiveness excellent company award among KNQA. We performed a statistical analysis of audit data for quality competitiveness excellent company for three years, from 2015 to 2017. By using ANOVA and two sample t-tests, the average scores of 13 evaluation fields were significantly different depending on company size and type. We proposed ways to improve the current hall of fame system. We discovered that the average scores of 13 evaluation fields in the audit data according to years and hall of fame status were not significantly different. We also showed linear relationships among 13 evaluation fields by correlation analysis and obtained an estimated linear regression equation : Business Performance, which is a comprehensive index, as a dependent variable was significantly related to Customer Focus and Product Liability as regressor variables among 13 evaluation fields by regression analysis.

The pea aphid Acyrthosiphon pisum is a polyphagous, sap-sucking insect pest with a worldwide distribution. We investigated the developmental time and survivorship in nymphs and longevity and fecundity in adults of A. pisum at five different temperatures applying with following two programs, TWOSEX-MSChart and TIMING-MSChart. Regarding to thermal effect on A. pisum, in this presentation, we will discuss about a population projection and following population parameters calculated in this study: adult preoviposition period (APOP), total preoviposition period (TPOP), oviposition days, eggs per reproductive female, first age of survival rate <50%, proportion of male and female individuals, and life table parameters (net reproductive rate, intrinsic rate of increase, finite rate of increase, and mean generation time).

This study was conducted targeting 30 residents of Gwangyang industrial complex area from April to May 2017 to assess their level of exposure to VOCs and conduct a health risk assessment for individual exposure. The aim was to understand the difference in levels of indoor, outdoor and personal exposure to VOCs (benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene) and a health risk assessment was conducted to determine whether there was any fatal cause from carcinogenic or non-carcinogenic elements from a respiratory disease patients. In the case of benzene in the air, the geometric levels of the group are indoor, outdoor and personal exposure; on the CTE, RME condition and Monte-Carlo analysis, all subjects were seen to exceed the carcinogenicity tolerance of 10−6 specified by the US EPA. In the case of toluene, ethylbenzene, m-xylene, p-xylene, o-xylene on the CTE, RME condition and Monte-Carlo analysis, the non-carcinogenic standard of 1 was not exceeded.

Occurrence characterization of oriental corn borer, Ostrinia furnacalis, in a paddy-upland rotation field for 8 maize and 7 sorghum varieties was surveyed. In a monitoring study using a pheromone trap carried out from 15 May to 10 September, the density of O. furncalis adults increased rapidly from about 2 weeks after corn planting and reached the highest density at mid June. After that, their density was decreased and increased a little at earlier September. In a survey carried out at harvest period using 8 corn varieties, the damage ratio was Daehakchal (94%), Mibaek 2 (92%), Ilmichal (71%), Eolrukchal 1 (64%), Chalok 4 (54%), Miheukchal (52%), Heugjeom 2 (45%). The number of invasive pore per Ilmichal stem by O. furnacalis larvae was 1.4 and those of the others was less than 1.0. In another survey carried out at harvest period using 7 sorghum varieties, their damage ratios were DS-202 (95%), Moktaksusu (76%), Sodamchal (75%), Nampungchal (67%), Anzunbaengisusu (57%), Donganme (46%), and Hwanggeumchal (34%). The damage of sorghum varieties was much higher and severer than that of corn by O. furnacalis larvae. These results may be useful for the establishment of a management strategy to control oriental corn borer in paddy-upland rotation fields for maize and sorghum.

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.

Toxicities of 10 insecticides were examined against late third instars of Culex tritaeniorhynchus using the direct-contact mortality bioassay. Six geospatially distant field mosquitoes were collected from Chuncheon-si (designated CC-CT), Hwaseong (HS-CT), Seosan (SS-CT) Jeonju (JJ-CT), Daegu (DG-CT), and Busan (BS-CT) in the Republic of Korea (ROK). Marked regional variations of insecticide susceptibility were observed. Field populations of SS-CT, JJ-CT and DG-CT from agricultural areas showed higher to extremely higher insecticide susceptibility to pyrethroids than those of CC-CT, HS-CT and BS-CT strains from none agricultural areas. Extremely high to low levels of susceptibility were measured: bifenthrin, susceptible ratio (SR) = 2.7–896.3; β-cyfluthrin, SR = 1.8–633.3; α-cypermethrin, SR = 1.2–1,051.9; deltamethrin, SR = 1.3–711.1; permethrin, SR = 1.5–1,053.4 etofenprox, SR = 2.2–29.3; chlorfenapyr, SR = 5.1–103.6; chlorpyrifos, SR = 2.3–337.0; fenitrothion, SR = 2.0–142.3 and fenthion, SR = 1.4–186.2. Culex tritaeniorhynchus populations from rice paddies had been under heavy selection pressure due to the agricultural insecticides and that’s why the mosquito species demonstrated high resistance to pyrethroids which were used for a long time to control agricultural pests in the localities. These results indicate that careful selection and rotational use of these insecticides mayresult in continued satisfactory control against field populations of Japanese encephalitis vector mosquitoes.

The purpose of this study was to investigate the distribution of trig˗ ger points(TrPs) on athletes with various sporting background. To achieve the purpose, a study was carried out through a survey from 180 athletes involved in 6 selected sports at Yong-In University. Selected sports included Judo, Taekwondo, Kendo, Ssi-reum(Korean traditional wrestling), Boxing, and Golf. An interview type survey and physical examination were conducted with each thirty athletes from each of the selected sports groups. Technical statistic(SPSS 15.0) was used to analyze the distribution of TrPs on these athletes. The most common TrPs observed in muscles of Trapezius, Quadratus Lumborum, Quadriceps in Judo. In Taekwondo, it was on the trapez˗ ius and triceps surae. Kendo athletes had TrPs at sites of trapezius, brachioradialis and triceps surae. Ssirem athletes were found to have TrPs on trapezius, deltoid and quadrates lumborum. In boxers, TrPs appearing at trapezius and brachioradialis were observed. Finally, Golf players were seen to have TrPs at trapezius, quadrates lumbo˗ rum and brachioradialis. Hence, the analysis shows that there are significant differences of the distribution of TrPs according to the different sport items of the athlete.

지리산은 해발 1915m인 남한 본토 최고인 명산이며 국립공원으로 지정된 바도 있으나 아직 그 동물상에 대한 조사는 불충분한 바 있다. 1972년 8월 11일-14일의 4일간에 걸쳐 남궁 윤은 한라산 거미상과의 비교 검토를 위하여 지리산의 제 2 고봉인 반야봉과 제 3고봉인 노고단을 중심으로 한 지리산 서남면인 "겉지리산"의 일부를 조사하였다. 한편 백외는 1971년 7일 하순 화엄사, 노고단 및 피아골의 거미상에 대해 조사한 바 있다. 광대한 지리산의 전체적인 면모를 파악하기에는 미급한 조사였지만 대치적인 특징을 추찰한 수 있었기에 이에 보고코져 한다. 지리산 거미에 대하여는 백 갑용(1942-1972), 백운하외 (1970) 등에 의해 18과 76종 (3미확정종포함)이 보고된 바 있으나 채집기록에 불분명한 바가 있고, 그 환경이나 수직분포 등에 대하여는 언급된 바가 없었다. 금번 조사한 장소를 고도별로 보면 다음과 같다. 연곡사(300-400m), 화엄사(400-600m), 피아골(500-900m), 화엄사골(600-900m), 용수바위 (900-1300m), 코재 (900-1300m), 임걸령(1400-1500m), 노고단(1400-1550m), 반야봉(1550-1750m) (1) 이 조사보고에서는 종전의 보고에서 기록이 분명한 것을 종합하여 21과 135종 (미확정종 6종 포함)의 목록을 작성하였다. (2) 지리산 추가종 56종을 확인하였으며 그 중에서 한국 미기록종은 16종이다. (목록에 *표를 한 것) (3) 미확정종은 개체특징이 분명한 것만 수록했으며 이들 중 금후 연구로써 신종으로 기재됨 것도 있다. (4) 이번 조사의 결과로는 지리산의 거미상은 북방종 26종 남방종 8종 세계공통종이 3종으로 북방온대성 의 경향이 짙으다. (5) 고도분포는 반야봉 (1550-1750m)에서 18종, 1400-1550m가 38종, 900-1400m에서 39종, 600-900m에서 72종, 600m이하에서 79종으로 고도가 높아짐에 따라 종수가 점감되고 1300m 이상에 서식하는 것은 44종에 불과하였다. (6) 지리산의 우점종은 대륙접시거미 (Prolinyphia emphana)로 600m 이상부터 산정부에 걸쳐 널리 분포하며, 개체수에 있어서도 가장 많았다. 깡충거미과(Salticidae), 늑대거미과(Lycosidae)가 극히 적은 것도 특징적이라 하겠다.

최근 의료분야에서 X선은 질병의 진단 및 치료영역에서 필수적으로 요구되며, 영상의학 기술의 발전과 더불어 X선의 이용은 지속적으로 증가하는 추세지만, X선은 방사선 피폭의 단점을 가지고 있다. 방사선피폭을 방어하기 위해 임상에서는 납 방호도구를 사용하지만 납은 중금속으로 분류되어 납중독 등 인체에 유해한 반응을 일으킬 수 있다. 따라서 본 연구는 FDM(Fused Deposition Modeling)방식의 3차원 프린터의 재료를 이용하여 제작한 차폐체의 유용성을 알아보고자 한다. 필라멘트의 선감약계수를 확인하기 위해 PL A, XT-CF20, Wood, Glow, Brass를 이용해 팬텀을 제작 하고, CT scan을 하였다. 그리고 100 × 100 × 2 ㎜ 크기의 차폐 시트를 모델링하고, 진단용 X선발생장치와 조사선량계를 이용하여 선량 및 차폐율을 측정하였으며, 납 방호도구와의 차폐율을 비교하였다. 실험결과 Brass의 CT number가 가장 높게 측정되어 Brass를 이용하여 차폐시트를 제작하였으며, 진단용 X선발생장치로 확인한 결과 100 kV, 40 mAs 조건으로 X선 조사 시 6 ㎜ 두께의 차폐시트에서 차폐율이 90 % 이상으로 측정되어 apron 0.25 ㎜Pb보다 차폐율이 높은 것을 확인하였다. 본 연구의 결과 3차원 프린팅 기술로 제작한 차폐체가 진단용 X선 영역에서 높은 차폐율을 보이는 것을 확인하였으며, 납 방호도구와의 비교를 통하여 납을 대체하여 방사선 방호도구로서의 가능성을 알 수 있었다.

방사선 피폭감소를 위해 사용하는 비스무스 차폐체를 적용하여 CT스캔 시 차폐체에 의한 선속경화현상으로 화질이 감소되는 경우가 있다. 이에 G사의 듀얼 에너지 CT의 GSI모드 적용을 통해 화질저하 현상을 줄일 수 있는 에너지 영역대를 찾아보고, 가능성을 실험을 통해 알아보고자 하였다. 그 결과 비스무스 차폐 후 듀얼 에너지 CT 스캔 시 50 keV에서 118±10.6 HU, 50.1±14.6 HU로 화질저하 전 CT value와 가장 유사 하였고(p>0.05), Image J의 Multi-point기능을 적용한 Pixel value에서도 50 keV에서 176.6±7.1, 138.3±1.1로 측정 되었다(p>0.05). CT검사 시 차폐체의 사용은 불가항력적으로 화질저하를 유발하지만 듀얼 에너지 CT 의 GSI기능 적용으로 차폐체를 사용하고도 화질을 유지할 수 있다는 것을 실험을 통해 알 수 있었다. 향후 다양한 차폐체를 듀얼 에너지 CT를 이용, 평가 후 보안 한다면 CT검사의 최대 단점인 피폭 감소를 위한 방사선 차폐체 사용으로 발생한 화질저하라 단점을 극복할 수 있을 것으로 기대된다.

3-dimensional(D) 프린터는 컴퓨터로 모델링 한 데이터를 바탕으로 3차원의 입체 물체를 출력할 수 있는 장비이다. 이러한 특징을 방사선과학 분야와 융합하여, CT 데이터를 이용한 뼈 모형 X선 팬텀제작 등에 활용되고 있다. 본 연구는 기존의 Pelvis팬텀을 CT 스캔하고 얻어진 데이터로 Fused Filament Fabrication(FFF) 3D 프린터의 소재인 PLA, Wood, XT-CF20, Glow fill, Steel 필라멘트를 이용하여, 뼈 모형 팬텀을 제작하였다. 기존의 Pelvis 팬텀과 3D 프린터로 제작된 5가지 재질의 팬텀을 동일한 조건으로 CT 스캔 하고 얻어진 영상에서 Hounsfield Unit(HU)을 측정하였으며, 진단용X선 발생장치를 이용하여 SI, SNR을 측정하여 각 팬텀을 비교 분석하였다. 그 결과 사지 X선 검사 조건 내에서 X선 팬텀은 glow fill 필라멘트가 가장 적합하다는 것을 알 수 있었다. 본 연구의 기반으로 필라멘트의 특성들을 알 수 있었으며, X선 팬텀 제작에 대한 실용성을 확인하였다.