• Title/Summary/Keyword: performance-measure

Search Result 5,159, Processing Time 0.034 seconds

Design and Fabrication of a Field Mill for Ground-Level Electric Field Measurement (대지전계 측정을 위한 필드밀의 설계 및 제작)

  • Kil, Gyung-Suk;Song, Jae-Yong;Kim, Il-Kwon;Kwon, Jang-Woo;Ahn, Chang-Hwan;Lee, Young-Keun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.21 no.1
    • /
    • pp.52-59
    • /
    • 2007
  • A field mill capable of measuring the magnitude and polarity of electric fields at the ground level was studied to apply to a lightning warning system as a sensor. We designed and fabricated a planar-shutter type field mill with a rotating-vanes. A calibration of the field mill was performed in a vertically symmetrical arrangement which consists of two equal size parallel round plates to form a homogeneous electrical fields. The sensitivity of the field mill was adjusted at 0.5[V/kV/m], and this covers a ranges from 200[V/m] to 20[kV/m]. After the calibration experiment, the field mill was installed on the roof of a building to measure the changes of electric field intensity caused by thunderclouds. During the period from July 1. 2006 to July 15. 2006, the electric field intensity was recorded a ranges of $+2[kV/m]{\sim}-6[kV/m]$ depending on generation, extinction and movement of thunderclouds. From the actual test on the ground it is confirmed that the field mill has a good performance necessary for the measurement of DC electric fields.

Content based Video Segmentation Algorithm using Comparison of Pattern Similarity (장면의 유사도 패턴 비교를 이용한 내용기반 동영상 분할 알고리즘)

  • Won, In-Su;Cho, Ju-Hee;Na, Sang-Il;Jin, Ju-Kyong;Jeong, Jae-Hyup;Jeong, Dong-Seok
    • Journal of Korea Multimedia Society
    • /
    • v.14 no.10
    • /
    • pp.1252-1261
    • /
    • 2011
  • In this paper, we propose the comparison method of pattern similarity for video segmentation algorithm. The shot boundary type is categorized as 2 types, abrupt change and gradual change. The representative examples of gradual change are dissolve, fade-in, fade-out or wipe transition. The proposed method consider the problem to detect shot boundary as 2-class problem. We concentrated if the shot boundary event happens or not. It is essential to define similarity between frames for shot boundary detection. We proposed 2 similarity measures, within similarity and between similarity. The within similarity is defined by feature comparison between frames belong to same shot. The between similarity is defined by feature comparison between frames belong to different scene. Finally we calculated the statistical patterns comparison between the within similarity and between similarity. Because this measure is robust to flash light or object movement, our proposed algorithm make contribution towards reducing false positive rate. We employed color histogram and mean of sub-block on frame image as frame feature. We performed the experimental evaluation with video dataset including set of TREC-2001 and TREC-2002. The proposed algorithm shows the performance, 91.84% recall and 86.43% precision in experimental circumstance.

A Study of the Application of Precepter Program with the Reducion of the Time of New Entry Nurse Orientation. (신입간호사 교육 기간 단축에 따른 Preceptor program 적용에 관한 연구)

  • Kim, Hae-Sook;Kim, Lee-Young;Choi, Sun-Sook;Han, Mee-Jung;Kim, Sun-Hee;An, Young-Hee;Kong, Sung-Hwa;Jang, Soo-Ryeon;Kim, Mee-Ae;Kim, Soo-Young
    • The Korean Nurse
    • /
    • v.37 no.4
    • /
    • pp.58-71
    • /
    • 1998
  • The purpose of this study was to contribute the improvement of nursing staff development by implementing of effective and organized orientation program using the measure of effectiveness in the application of preceptor program with the reduction of the time of New entry nurse orientation. The subjects were comprised of 116 new entry nurses(59 new entry nurses were employed at June, 1996 and 57 at May & July, 1997) and 79 preceptors, who were in charge of new entry nurse orientation at 1997. These date were collected from June 18, 1996 to August 29, 1997. The characteristics of questionairs applied in this study were general characteristics(7 questions), knowledge of nursing care(138 questions); attitude toward her profession(40 questions) and the degree of satisfaction for the program(5 questions). The questionnairs were developed by the researchers of Asan Medical Center. The Check-list for basic nursing skill were used for the measurement of nursing skill which was developed by nursing department of AMC. The data were analyzed for the mean, standard deviation, difference of mean, ANOV A & t-test. The results of this study are as follows : 1) The changes in knowledge of nursing care : After three months of training the difference of mean between before and after the orientation was higher than the result of two month period training. However, the result was insignificant(p= .469). 2) Performance in nursing practice : Two month period orientation was more effective than three-month training period, however, the statistical significance can not be reached than 3 month period, which resulted in insignificant difference(p=.150). 3) The change in attitude toward her profession : After three-month of orientation, the difference of mean between before and after the orientation was higher than 2 month period orientation, which resulted in significant difference (p=.000). 4) The degree of satisfaction for the program with the time of new entry nurse orientation : After two-month of orientation, the mean of points was 2.57 where the score is higher than 3 month period with mean of 2.30. It resulted in significant difference(p=.000).

  • PDF

Estimated Soft Information based Most Probable Classification Scheme for Sorting Metal Scraps with Laser-induced Breakdown Spectroscopy (레이저유도 플라즈마 분광법을 이용한 폐금속 분류를 위한 추정 연성정보 기반의 최빈 분류 기술)

  • Kim, Eden;Jang, Hyemin;Shin, Sungho;Jeong, Sungho;Hwang, Euiseok
    • Resources Recycling
    • /
    • v.27 no.1
    • /
    • pp.84-91
    • /
    • 2018
  • In this study, a novel soft information based most probable classification scheme is proposed for sorting recyclable metal alloys with laser induced breakdown spectroscopy (LIBS). Regression analysis with LIBS captured spectrums for estimating concentrations of common elements can be efficient for classifying unknown arbitrary metal alloys, even when that particular alloy is not included for training. Therefore, partial least square regression (PLSR) is employed in the proposed scheme, where spectrums of the certified reference materials (CRMs) are used for training. With the PLSR model, the concentrations of the test spectrum are estimated independently and are compared to those of CRMs for finding out the most probable class. Then, joint soft information can be obtained by assuming multi-variate normal (MVN) distribution, which enables to account the probability measure or a prior information and improves classification performance. For evaluating the proposed schemes, MVN soft information is evaluated based on PLSR of LIBS captured spectrums of 9 metal CRMs, and tested for classifying unknown metal alloys. Furthermore, the likelihood is evaluated with the radar chart to effectively visualize and search the most probable class among the candidates. By the leave-one-out cross validation tests, the proposed scheme is not only showing improved classification accuracies but also helpful for adaptive post-processing to correct the mis-classifications.

Pedestrian Traffic Counting Using HoG Feature-Based Person Detection and Multi-Level Match Tracking (HoG 특징 기반 사람 탐지와 멀티레벨 매칭 추적을 이용한 보행자 통행량 측정 알고리즘)

  • Kang, Sung-Wook;Jung, Jin-dong;Seo, Hong-il;Lee, Hae-Yeoun
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.5 no.8
    • /
    • pp.385-392
    • /
    • 2016
  • Market analysis for a business plain is required for the success in the modern world. Most important part in this analysis is pedestrian traffic counting. A traditional way for this is counting it in person. However, it causes high labor costs and mistakes. This paper proposes an automatic algorithm to measure the pedestrian traffic count using images with webcam. The proposed algorithm is composed of two parts: pedestrian area detection and movement tracking. In pedestrian area detection, moving blobs are extracted and pedestrian areas are detected using HoG features and Adaboost algorithm. In movement tracking, multi-level matching and false positive removal are applied to track pedestrian areas and count the pedestrian traffic. Multi-level matching is composed of 3 steps: (1) the similarity calculation between HoG area, (2) the similarity calculation of the estimated position with Kalman filtering, and (3) the similarity calculation of moving blobs in the pedestrian area detection. False positive removal is to remove invalid pedestrian area. To analyze the performance of the proposed algorithm, a comparison is performed with the previous human area detection and tracking algorithm. The proposed algorithm achieves 83.6% accuracy in the pedestrian traffic counting, which is better than the previous algorithm over 11%.

Image Registration for PET/CT and CT Images with Particle Swarm Optimization (Particle Swarm Optimization을 이용한 PET/CT와 CT영상의 정합)

  • Lee, Hak-Jae;Kim, Yong-Kwon;Lee, Ki-Sung;Moon, Guk-Hyun;Joo, Sung-Kwan;Kim, Kyeong-Min;Cheon, Gi-Jeong;Choi, Jong-Hak;Kim, Chang-Kyun
    • Journal of radiological science and technology
    • /
    • v.32 no.2
    • /
    • pp.195-203
    • /
    • 2009
  • Image registration is a fundamental task in image processing used to match two or more images. It gives new information to the radiologists by matching images from different modalities. The objective of this study is to develop 2D image registration algorithm for PET/CT and CT images acquired by different systems at different times. We matched two CT images first (one from standalone CT and the other from PET/CT) that contain affluent anatomical information. Then, we geometrically transformed PET image according to the results of transformation parameters calculated by the previous step. We have used Affine transform to match the target and reference images. For the similarity measure, mutual information was explored. Use of particle swarm algorithm optimized the performance by finding the best matched parameter set within a reasonable amount of time. The results show good agreements of the images between PET/CT and CT. We expect the proposed algorithm can be used not only for PET/CT and CT image registration but also for different multi-modality imaging systems such as SPECT/CT, MRI/PET and so on.

  • PDF

A Research on Ship Hull Roughness : Estimation Method and Effect on Ship Performance (선박의 표면조도에 관한 연구 : 추정법 및 선박성능에 미치는 영향)

  • Kwon, Y.J.;Choo, D.K.
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.33 no.2
    • /
    • pp.30-35
    • /
    • 1996
  • It is well known that the improved methods of the estimation of the service power margin is necessary to design a optimum ship and to operate economically a ship. Unfortunately, most conventional methods of the predicting of the service power margin are not so accurate that attention should be payed to improve this. From this overview, it is importance with. the effects of waves, as recommended by the 15th and 16th International Towing Tank Conference in 1978 and l981. However the progress of research in this field is very slow mainly since it is taken so long time to take data about hull roughness according to ship ages. For instance, it would be taken 17 or 25 years to measure ideally the data for a ship. Moreover it would be also necessary to take data for many types of ships to lead a general solution. A relationship between roughness and ship age are studied in this paper considering full scale data. A comparison is also made between the effects of hull roughness and of weather at sea for the ship.

  • PDF

Comparison of temperature measurements methods to investigate the causes of deformation of packaging materials during microwave heating (전자레인지의 가열조리 시 포장재의 열변형 원인 규명을 위한 온도 측정 방법 비교)

  • Yoon, Chan Suk;Lee, Hwa Shin;Pfeiffer, Thomas;Cho, Ah Reum;Moon, Sang Kwon;Lee, Keun Taik
    • Food Science and Preservation
    • /
    • v.23 no.3
    • /
    • pp.422-431
    • /
    • 2016
  • To investigate the causes of the thermal deformations of packaging materials when microwave-heating ready-to-eat sauce products packaged in stand-up pouches, patterns of temperature changes were determined using an infra-red thermal imaging camera, a thermo-sensitive tape, and a fiver-optic thermometer. The temperature distributions of spicy chicken sauce and Indian curry samples in a stand-up pouch were found to be uneven during micrewave heating. A sharp increase in the temperature was detected, especially above the filling layers and in the corners of sealing layers of the package. The temperature measurements using an infra-red thermal imaging camera are restricted to the surface, and therefore might underestimate the actual temperature. Using a thermo-sensitive tape, temperature up to $200^{\circ}C$ were measured in the spicy chicken sauce sample showing package deformation. When the temperature is measured using a fiber-optic thermometer, it is crucial to have precise sensor performance to accurately measure the temperature in a narrow hot-spot area of the package. In this experiment, the fiber-optic thermometer was attached to a GaAs crystal sensor, which obtained more sensitive and accurate temperature measurements than those by a convectional sensor.

Causes of Top Dead Center Error in Marine Generator Engine Power-Measuring Device (선박용 발전기 엔진 출력 측정 장치의 TDC 오차 발생 원인)

  • Lee, Ji-Woong;Jung, Gyun-Sik;Lee, Won-Ju
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.26 no.4
    • /
    • pp.429-435
    • /
    • 2020
  • Different methods are used for determining the output of engines to obtain the indicated horsepower by measuring the combustion pressure of cylinders, and to obtain the shaft horsepower by measuring the shaft torque. It is difficult to examine the shaft torque using the condition of the cylinder, and the most accurate method used for determining the combustion pressure involves examining the combustion state of the cylinder to evaluate the engine performance and analyze the combustion of the cylinder. During the measurement, the combustion pressure is the most important parameter used for accurately determining the cylinder angle because the cylinder pressure is indicated based on the angle of the crankshaft. In this study, an encoder was used as the crank angle sensor to measure the cylinder pressure on the generator engine of the actual operating ship. The reasons for the differences between the top dead center (TDC) recognized by the encoder (TDCencoder) and the TDC recognized by the compression pressure (TDCcomp) were considered. The dif erences between the TDCcomp and TDCencoder of the cylinders measured at idle running, 25 %, 50 %, and 60 % loads were analyzed to determine for the crankshaft production effect, the crankshaft torsion effect owing to the increased rotational resistance from the increased load, and the coupling damping effect between the engine and generator. It was confirmed that the TDC error occurred up to 3° crank angle as the load of the generator increased.

A Study of the Effects of Job-seeking Efficacy on Use Intention and Outcome of the Work-net (구직효능감(job-seeking efficacy)으로 인 한 Work-net의 이용의도 및 성과에 관한 연구)

  • Oh, Seong-Uk;Yoon, Sung-Joon
    • Journal of Global Scholars of Marketing Science
    • /
    • v.13
    • /
    • pp.113-133
    • /
    • 2004
  • The present study examines the the role of subjectively perceived factors of the attitude toward job-seeking activities in forming an intention to use a web. An integrative research model is presented and tested empirically. It includes the following two aspects of belief in Davis' TAM: perceived usefulness, perceived ease of use. Specially, internet job-seeking efficacy, or the belief in one's capabilities to organize and execute courses of Internet actions required to achieve given goals, is a potentially important factor in efforts to gain more favorable attitude toward Internet uses. Survey data were collected to develop a reliable operational measure of Internet job-seeking efficacy and to examine its construct validity. An four-item Internet job-seeking efficacy scale developed for the present study was found to be reliable and internally consistent. Also, many previous studies have established that perceived usefulness is an important factor influencing user acceptance and usage behavior of information technologies. However, very little research has been conducted to understand how that perception forms and changes over time. The current work presents and tests the determinants of perceived usefulness. The present study found that higher internet job-seeking efficacy is an important concept which is significantly related to job-seeking activities by positively influencing intention and performance as well as usefulness on the Internet.

  • PDF