정교한 데이터 분류를 위한 방법론의 고찰

김승재,김성환,Kim, Seung Jae,Kim, Sung Hwan 조선대학교 기초과학연구원 2021 조선자연과학논문집 Vol.14 No.1

전 세계적으로 인공지능(AI)을 구현하려는 움직임이 많아지고 있다. AI구현에서는 많은 양의 데이터, 목적에 맞는 데이터의 분류 등 데이터의 중요성을 뺄 수 없다. 이러한 데이터를 생성하고 가공하는 기술에는 사물인터넷(IOT)과 빅데이터(Big-data) 분석이 있으며 4차 산업을 이끌어 가는 원동력이라 할 수 있다. 또한 이러한 기술은 국가와 개인 차원에서 많이 활용되고 있으며, 특히나 특정분야에 집결되는 데이터를 기준으로 빅데이터 분석에 활용함으로써 새로운 모델을 발견하고, 그 모델로 새로운 값을 추론하고 예측함으로써 미래비전을 제시하려는 시도가 많아지고 있는 추세이다. 데이터 분석을 통한 결론은 데이터가 가지고 있는 정보의 정확성에 따라 많은 변화를 가져올 수 있으며, 그 변화에 따라 잘못된 결과를 발생시킬 수도 있다. 이렇듯 데이터의 분석은 데이터가 가지는 정보 또는 분석 목적에 맞는 데이터 분류가 매우 중요하다는 것을 알 수 있다. 또한 빅데이터 분석결과 통계량의 신뢰성과 정교함을 얻기 위해서는 각 변수의 의미와 변수들 간의 상관관계, 다중공선성 등을 고려하여 분석해야 한다. 즉, 빅데이터 분석에 앞서 분석목적에 맞도록 데이터의 분류가 잘 이루어지도록 해야 한다. 이에 본 고찰에서는 AI기술을 구현하는 머신러닝(machine learning, ML) 기법에 속하는 분류분석(classification analysis, CA) 중 의사결정트리(decision tree, DT)기법, 랜덤포레스트(random forest, RF)기법, 선형분류분석(linear discriminant analysis, LDA), 이차선형분류분석(quadratic discriminant analysis, QDA)을 이용하여 데이터를 분류한 후 데이터의 분류정도를 평가함으로써 데이터의 분류 분석률 향상을 위한 방안을 모색하려 한다.

전자현미경의 이미지 향상을 위한 주사시스템의 안정성

김승재,김동환,Kim, Seung-Jae,Kim, Dong-Hwan 한국생산제조학회 2009 한국생산제조학회지 Vol.25 No.1

In a scanning electron microscopy, image distortion is a critical issue and it is needed to be eliminated by some kinds of schemes. In this work, scanning frequency and scanning wave form are adjusted to have an improved image. The relationship between scan coil and its driver is investigated and appropriate frequency and wave form are suggested. It is proved that the selected frequency and wave form showed an enhanced image with less distortion, which were done by experiments. In addition, a noise elimination is addressed, providing improved image with a GROUND signal integration with the amplifier and the scan driver.

Disciplinary Sport Biomechanics : The Effect of Arch Height and AJC ROM on Foot - to - Leg Movement in Heel - Toe Running

김승재,이성철 ( Seung Jae Kim,Sung Cheol Lee ),Benno M . Nigg,Patria A . Hume 한국체육학회 1996 국제스포츠과학 학술대회 Vol.1996 No.2

돼지 생식기 및 호흡기 증후군 진단을 위한 in situ hybridization 기법의 응용

김승재,박남용,Kim, Seung-jae,Park, Nam-yong 대한수의학회 1997 大韓獸醫學會誌 Vol.37 No.4

We tried to develop detection system of porcine reproductive and respiratory syndrome virus(PRRSV) by in situ hybridization(ISH) in the piglets experimentally infected with KPRRS-2, the Korean isolate(12 piglets) or Mn-1b, the American isolate(4 piglets), and in the natural infection suspected 6 piglets. Twelve 30-days-old piglets(two pigs per each inoculated group) were inoculated by nasal instillation of KPRRS-2 virus(total dose $10^{4.5}TCID_{50}$), Six piglets(one pig per each group) were induced contact infection with inoculated piglets, during the experiment, and two piglets were used as control. Inoculated or contacted piglets were euthanized at 1, 3, 5, 7, 14 and 21 days postinoculation(DPI). The respiratory signs such as coughing and nasal discharge were observed on day 3 DPI, and ear cyanosis were on day 5 DPI, including contacted piglets. Through the necropsy, purple discolorization of dorsal part of lung, and hypertrophy of local lymph nodes were observed. The histopathological lesions of lung were interstitial pneumonia characterized by type 2 pneumocyte hyperplasia. We prepared the probe for ISH by RNA isolation from KPRRS-2, RT-PCR, and biotin labeling. We performed the ISH within only 1~2 hours using $Microprobe^{TM}$ capillary action system. As the results, the strong red specific positive signals, means PRRSV distribution, was mainly observed in the cytoplasm of alveolar macrophages. And also signals were detected in some type 2 pneumocytes and bronchiolar epithelium of lung, myocardium, liver, kidney, tonsil, spleen, gastrointestinal mucosa, testis and lymph nodes.

가공의치의 임상 통계적 연구

김승재,Kim, Seung-Jae 대한치과보철학회 1980 대한치과보철학회지 Vol.18 No.1

An investigation was made Into 1,357 fixed bridges which had been performed at the Department of Prosthetic Dentistry, Seoul National University Hospital from 1973 to 1979. The purpose of this investigation was to establish a basic reference of the treatment with fixed bridges by obtaining statistical conclusions from the data concerning the patients who had been treated with fixed bridges. The following conclusions were obtained; 1. The ratio of the fixed bridges made on the maxillae to those made on the mandible was 1:1. 2. The cases of fixed bridges with one pontic were the most frequent, i.e., 946 cases out of total 1,357 cases, which were 69.7% of the total. 3. As the number of missing teeth increased, the number of the relevant cases of fixed bridges decreased. 4. The most frequent age group of the patients who had been treated with fixed bridges was the twenties, which was 40.8% of the total. As the age of the patients increased, the number of corresponding cases of fixed bridges decreased. 5. Most of the fixed bridges with more than three pontics were made at the anterior portion samely on the maxilla and on the mandible. 6. As for the retainers, the porcelain fused to metal crown and the partial veneer crown were frequently used at the anterior portion, while the full veneer crown was frequently used and the inlay and the attachment were used in some cases at the posterior portion. The locations of fixed bridges in the order of their frequency were: canine, lateral incisor, second bicuspid, central incisor, second molar, first bicuspid, first molar, and third molar on the maxilla; second bicuspid, second molar, first bicuspid, first molar, canine, third molar, lateral incisor, and central incisor on the mandible.

구조응력법을 이용한 소켓용접배관 피로수명평가기법

김승재(Seung Jae Kim),이현재(Hyun Jae Lee),김지수(Ji Su Kim),이동민(Dong Min Lee),김윤재(Yun Jae Kim) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Small bore pipes of secondary system in power plant are socket welded for connection. During welding process, weld defect is formulated by incomplete penetration during welding. Due to these geometric discontinuity region, structural fatigue life of socket welded pipe can be affected. In this paper, to predict fatigue life of socket welded pipe considering defect, structural stress is applied to evaluate stress at geometric discontinuity region. Also, equivalent structural stress and master S-N curve, which are derived from fracture mechanics, are proposed as an evaluation.

D유형 성격과 인구사회학적 특성 및 심혈관질환 위험요인과의 관계

김승재(Seung Jae Kim),허선(Sun Hur) 한국여성체육학회 2011 한국여성체육학회지 Vol.25 No.3

The purpose of this study was to investigate the relationships between socio-demographic characteristics and risk factors of cardiovascular disease and type D personality. The participants were 716 healthy females (aged 30 and older). Data were collected using a Korean version of type D scale-14 (DS14) development by Lim et al.(2011). Descriptive statistics and χ2 test and binary logistic regression were conducted. Results were as follows; 34.8% of the participants were classified as type D personality, of these females, 39.5% as negative affectivity and 32.0% as social inhibition. Type D personality differed significantly from non-type D personality on partner, economic status, social activity, exercise, health status and illness. Predictors of type D personality were partner(B=-1.661), poor exercise(B=-.514), frequency of exercise(B=-3.886), lower health status(B=-.969), and illness(B=.725). Especially, the influences of illness is the most important factor in type D personality. The results of this study were discussed with the effects of regular exercise behavior on D type personality and a systematic approach to the relationship between them for future study.

특수체육교사의 통합스포츠동아리 운영 경험 탐색

김승재 ( Seung-jae Kim ),임효경 ( Hyo-kyoung Im ) 한국특수체육학회 2017 한국특수체육학회지 Vol.25 No.1

본 연구의 목적은 특수교사가 장애학생들의 통합체육 활동의 기회를 확대하기 위해 창의적 체험활동의 영역인 동아리활동으로 `통합스포츠동아리`를 운영하면서 시간의 흐름에 따라 나타나는 학생들의 다양한 모습과 변화과정 그리고 동아리 운영 교사의 경험을 탐색하는데 있다. 연구 참여자는 강원도 A고등학교 특수학급담당교사(특수체육전공) 2명, 특수교육 실무사 2명, 비장애학생 12명, 장애학생 11명이다. 본 연구는 1년 동안 통합스포츠 동아리를 조직·운영하면서 작성한 교사 수업일지와 심층 면담자료, 학생자기평가서 등의 자료를 수집하여 분석하였다. 그 결과 `다른 출발선에서의 시작`, `새로움 속에서 공통점(즐거움) 발견하기`, `원활한 운영에 걸림돌`, ` 느린 변화 속에서 의미 찾기`라는 총 4개의 주제어가 도출되었다. 역 통합의 시도가 처음에는 어려움을 겪었지만, 학생들이 선호하는 프로그램을 제공하고 교사가 적절한 중재를 한 결과, 시간의 흐름에 따라 두 집단의 학생 모두 변화된 모습을 나타냈으며, 통합체육의 긍정적인 효과를 경험한 것으로 나타났다. The purpose of this study was to expanded opportunities for inclusive physical activity in favor of students with disabilities. This study was carried out as club participation, which is one of the creative experiential activities and aims to explore the various aspects of students, their processes of change, and the experiences of the instructors that appear in accordance with the passage of time while running an `inclusive sports club`. In addition, it focuses on exploring the educational values of inclusive physical activity and sharing the results. The participants consist of two adapted physical educators, two special education paraprofessional, 12 students without disabilities and 11 students with disabilities from A High School in Gangwon-do. Data such as teachers` diaries that were written during the year of operating an inclusive sports club/group, in-depth interview information, and self-evaluation forms of students were collected and analyzed for this study. As a result, a total of four key phrases `starting from a different starting line`, `discovering common grounds(pleasure) in novelty`, `obstacles in smooth operations`, as well as `finding meaning in slow changes` were introduced.

소형 드론을 활용한 온실 작물 이미지 분석 시스템에 관한 연구

김승재(Kim Seung Jae),최현오(Choi Hyeon O),김재헌(Kim Jae Heon),여현(Yoe Hyun) 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.6

스마트 축산 사양관리 장치의 표준 소개 및 확산 방향 제시

김승재(Kim Seung Jae),박세리(Park Se Ri),이명훈(Lee Meong Hun) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2