• Title/Summary/Keyword: Measures of Performances

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Face Recognitions Using Centroid Shift and Independent Basis Images (중심이동과 독립기저영상을 이용한 얼굴인식)

  • Cho Yong-Hyun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.5
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    • pp.581-587
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    • 2005
  • This paper presents a hybrid face recognition method of both the first moment of image and the independent component analysis(ICA) of fixed point(FP) algorithm based on Newton method. First moment is a method for finding centroid of image, which is applied to exclude the needless backgrounds in the face recognitions by shifting to the centroid of face image. FP-ICA is also applied to find a set of independent basis images for the faces, which is a set of statistically independent facial features. The proposed method has been applied to the problem for recognizing the 48 face images(12 persons o 4 scenes) of 64*64 pixels. The 3 distances such as city-block, Euclidean, negative angle are used as measures when match the probe images to the nearest gallery images. The experimental results show that the proposed method has a superior recognition performances(speed, rate) than conventional FP-ICA without preprocessing. The city-block has been relatively achieved more an accurate similarity than Euclidean or negative angle.

Determination of the Pallet Quantity Using Simulation in the FMS for Aircraft Parts (시뮬레이션 기법을 이용한 항공기 부품 가공 유연생산시스템의 팔레트 수량 결정)

  • Kim, Deok Hyun;Lee, In Su;Cha, Chun Nam
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.4
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    • pp.59-69
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    • 2018
  • This study deals with the case study on the pallet quantity determination problem for the flexible manufacturing system producing 32 different types of aircraft wing ribs which are major structures of an aircraft wings. A Korean company has constructed the WFMS (wing rib flexible manufacturing system) that is composed of several automated equipments such as the 5-axis machining centers, the RGV (rail guided vehicles)s, the AS/RS (automated storage and retrieval system), the loading/unloading stations, and so on. Pallets play a critical role in the WFMS to maintain high system utilization and continuous work flow between 5-axis machining machines and automated material handling devices. The discrete event simulation method is used to evaluate the performance of the WFMS under various pallet mix alternatives for wing rib manufacturing processes. Four performance measures including system utilization, throughput, lead-time and work in process inventory level are investigated to determine the best pallet mix alternative. The best pallet mix identified by the simulation study is adopted in setting up and operating a real Korean aircraft parts manufacturing shop. By comparing the real WFMS's performances with those of the simulation study, we discussed the cause of performance difference observed and the necessity of developing the CPS (cyber physical system).

Analysis of Performance on On-Offline Mixed Education and Training of Degree-linked Work-study Parallel System Focusing on Flipped Learning - (학위연계형 일학습병행제 온오프 혼합 교육훈련의 성과분석 - 플립러닝을 중심으로 -)

  • Jae Kyu Myung
    • Journal of Practical Engineering Education
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    • v.15 no.1
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    • pp.183-192
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    • 2023
  • This study analyzes the performance of flipped learning, an offline class method conducted in a degree-linked work-learning parallel system. Training in the work-study parallel system, which is conducted as part of job competency improvement, has thoroughly adhered to the offline method, but in line with COVID-19, unlike before, it is changing in the direction of using the online method more actively. However, educational methods such as flipped learning are not new because the degree-linked operation is applied to the academic system and education method of universities and is practically the same form as general university education. Therefore, it is necessary to analyze the educational performance and complementary points of flipped learning, which has recently been expanded in the degree-linked work-study parallel system, considering the characteristics of this system, in which classes are held only on weekends. As a result of statistical analysis based on the survey, some of the outcomes of flipped learning have been confirmed, and in order to increase the performances, it is necessary to continuously seek out specific measures to encourage learning and expand communication between instructors and students.

A Study of the Influence of Choice of Record Fields on Retrieval Performance in the Bibliographic Database (서지 데이터베이스에서의 레코드 필드 선택이 검색 성능에 미치는 영향에 관한 연구)

  • Heesop Kim
    • Journal of the Korean Society for Library and Information Science
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    • v.35 no.4
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    • pp.97-122
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    • 2001
  • This empirical study investigated the effect of choice of record field(s) upon which to search on retrieval performance for a large operational bibliographic database. The query terms used in the study were identified algorithmically from each target set in four different ways: (1) controlled terms derived from index term frequency weights, (2) uncontrolled terms derived from index term frequency weights. (3) controlled terms derived from inverse document frequency weights, and (4) uncontrolled terms based on universe document frequency weights. Su potable choices of record field were recognised. Using INSPEC terminology, these were the fields: (1) Abstract. (2) 'Anywhere'(i.e., ail fields). (3) Descriptors. (4) Identifiers, (5) 'Subject'(i.e., 'Descriptors' plus Identifiers'). and (6) Title. The study was undertaken in an operational web-based IR environment using the INSPEC bibliographic database. The retrieval performances were evaluated using D measure (bivariate in Recall and Precision). The main findings were that: (1) there exist significant differences in search performance arising from choice of field, using 'mean performance measure' as the criterion statistic; (2) the rankings of field-choices for each of these performance measures is sensitive to the choice of query : and (3) the optimal choice of field for the D-measure is Title.

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A Study of the Use of SNS for the Activation of School Library Marketing (SNS를 활용한 학교도서관 마케팅 활성화 방안 연구)

  • Lim, Jeong-Hoon
    • Journal of Korean Library and Information Science Society
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    • v.51 no.1
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    • pp.21-41
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    • 2020
  • This paper aims to propose ways to promote SNS marketing at school library sites with case study analyses in school libraries. To this end, in-depth interview was conducted with 10 Teacher Librarians who had used SNS in library operation and an in analysis was made of the operation status, motives and objectives, strategies and performances of the school library's SNS marketing. According to the study, most Teacher Librarians were found to be using SNS such as Facebook, Instagram, Kakao Plus Friends and so on in an attempt to improve accessibility and utilization of the library resources first. Not only that, they used SNS for the purpose of communicating with users while increasing the number of visitors and identifying the needs of users. The messages provided through SNS are information on school libraries and their reading programs, and the target market mainly involved their students. Based on the above research results, measures to promote SNS in school libraries were discussed, including the need for marketing consultative bodies, expansion of SNS targets, and enhancement of expertise in SNS.

A Study on Effectiveness Analysis of K2 system with Weapon's unit cost (무기체계 단위비용을 고려한 K2 체계의 효과분석 방법 연구)

  • Jung, Byungki
    • Journal of the Korea Society for Simulation
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    • v.26 no.2
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    • pp.31-39
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    • 2017
  • This paper analyses the effectiveness of Kill Chain (KC) and Korea Air and Missile Defense (KAMD), also known as the K2 systems, using monte carlo simulation. It is assumed that the K2 systems are consisted with unitary KC and multi-layered (upper-tier and lower-tier) KAMD. And each system has two or three arbitrary weapon systems and its combination makes 12 scenarios. Measures of effectiveness (MOE) of the K2 systems were defined as ratio of eliminated ballistic missiles from total threats. And total cost was calculated by number of weapon launched and its unit cost. MOE and total cost of the K2 systems were estimated using monte carlo simulation with a thousand iteration for each scenario. Cost-effectiveness analysis was performed and the best candidate was selected using fixed effectiveness approach. As a result, the performances of KC are prime factor that affects both effectiveness and total cost of the K2 systems. It is also, acquired proper level of lower-tier KAMD to achieve desired defense effectiveness. For future work, it needs to be performed cost-effectiveness analysis based on practical specification and life cycle cost of weapon systems.

COGNITIVE BIASES IN INTERPRETATION, EXPECTATION AND JUDGEMENT OF SOCIALLY ANXIOUS CHILDREN (사회불안 아동의 해석, 기대 및 판단에서의 인지 편향)

  • Yang, Yoon-Ran;Oh, Kyung-Ja
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.15 no.2
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    • pp.152-159
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    • 2004
  • Objective : The present study investigated the interpretation bias and expectation and judgemental bias of performance in socially anxious children. Method : Children with high social anxiety (n=18) and low social anxiety (n=16) were recruited through self-report and peer nomination, Participants performed three tasks to assess for cognitive bias. The first task measured interpretation of ambiguous social situations. The second task measured expectations regarding performance in a three minute impromptu speech. The third task assessed for judgemental bias via comparison between post-speech self rating and observer rating. Result : Children with high social anxiety did not differ significantly from low social anxiety children on the dependent measures assessing bias in interpretation, expectation and judgement. However, a significant difference was found in the judges' rating of children's performances on the speech task, with high social anxiety children obtaining significantly lower scores compared to low social anxiety children. Conclusion : The role of cognitive biases in the development and maintenance of social anxiety in children was discussed.

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Comparison of Variable Importance Measures in Tree-based Classification (나무구조의 분류분석에서 변수 중요도에 대한 고찰)

  • Kim, Na-Young;Lee, Eun-Kyung
    • The Korean Journal of Applied Statistics
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    • v.27 no.5
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    • pp.717-729
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    • 2014
  • Projection pursuit classification tree uses a 1-dimensional projection with the view of the most separating classes in each node. These projection coefficients contain information distinguishing two groups of classes from each other and can be used to calculate the importance measure of classification in each variable. This paper reviews the variable importance measure with increasing interest in line with growing data size. We compared the performances of projection pursuit classification tree with those of classification and regression tree(CART) and random forest. Projection pursuit classification tree are found to produce better performance in most cases, particularly with highly correlated variables. The importance measure of projection pursuit classification tree performs slightly better than the importance measure of random forest.

Motion Recognitions Based on Local Basis Images Using Independent Component Analysis (독립성분분석을 이용한 국부기저영상 기반 동작인식)

  • Cho, Yong-Hyun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.5
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    • pp.617-623
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    • 2008
  • This paper presents a human motion recognition method using both centroid shift and local basis images. The centroid shift based on 1st moment balance technique is applied to get the robust motion images against position or size changes, the extraction of local basis images based on independent component analysis(ICA) is also applied to find a set of statistically independent motion features, which is included in each motions. Especially, ICA of fixed-point(FP) algorithm based on Newton method is used for being quick to extract a local basis images of motions. The proposed method has been applied to the problem for recognizing the 160(1 person * 10 animals * 16 motions) sign language motion images of 240*215 pixels. The 3 distances such as city-block, Euclidean, negative angle are used as measures when match the probe images to the nearest gallery images. The experimental results show that the proposed method has a superior recognition performances(speed, rate) than the method using local eigen images and the method using local basis images without centroid shift respectively.

Night Time Leading Vehicle Detection Using Statistical Feature Based SVM (통계적 특징 기반 SVM을 이용한 야간 전방 차량 검출 기법)

  • Joung, Jung-Eun;Kim, Hyun-Koo;Park, Ju-Hyun;Jung, Ho-Youl
    • IEMEK Journal of Embedded Systems and Applications
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    • v.7 no.4
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    • pp.163-172
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    • 2012
  • A driver assistance system is critical to improve a convenience and stability of vehicle driving. Several systems have been already commercialized such as adaptive cruise control system and forward collision warning system. Efficient vehicle detection is very important to improve such driver assistance systems. Most existing vehicle detection systems are based on a radar system, which measures distance between a host and leading (or oncoming) vehicles under various weather conditions. However, it requires high deployment cost and complexity overload when there are many vehicles. A camera based vehicle detection technique is also good alternative method because of low cost and simple implementation. In general, night time vehicle detection is more complicated than day time vehicle detection, because it is much more difficult to distinguish the vehicle's features such as outline and color under the dim environment. This paper proposes a method to detect vehicles at night time using analysis of a captured color space with reduction of reflection and other light sources in images. Four colors spaces, namely RGB, YCbCr, normalized RGB and Ruta-RGB, are compared each other and evaluated. A suboptimal threshold value is determined by Otsu algorithm and applied to extract candidates of taillights of leading vehicles. Statistical features such as mean, variance, skewness, kurtosis, and entropy are extracted from the candidate regions and used as feature vector for SVM(Support Vector Machine) classifier. According to our simulation results, the proposed statistical feature based SVM provides relatively high performances of leading vehicle detection with various distances in variable nighttime environments.