• Title/Summary/Keyword: occurence frequency

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Modeling the Occurence of High-frequency Reignition Oscillation by Closing the Vacuum Circuit Braker on the Electric Railway Vehicle (전기철도차량용 진공차단기의 투입에 따른 고주파 재발호 진동발생 모의분석)

  • Jeong, Ki-Seok;Jang, Uk-Dong;Chung, Jong-Duk
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1593-1594
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    • 2015
  • 본 논문에서는 진공 차단기의 투입 시 발생하는 고주파 재발호 진동현상을 모의하여 계통의 전압-주파수 특성을 분석한다. 우선 시간영역에서 차단기 투입에 따른 개폐 서지 현상을 모의하여 다중 재발호에 의한 진행파의 주파수 특성을 검토한다. 모의 결과를 통해 추정된 고주파 회로저항과 기존 전원, 고압케이블, 변압기로 구성된 고주파 재발호 진동해석용 등가 회로를 구현하고 주파수 스캔 기능을 이용하여 인가되는 전압의 주파수 변화에 따른 계통의 임피던스 크기변화를 확인한다. 끝으로, 시간 영역 및 주파수 영역에서 도출된 계통의 공진 주파수와 철도차량용 주 변압기의 공진주파수를 비교하여 내부 공진 여부에 따른 권선간 전압 확대 가능성을 논하고자 한다.

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Text Summarization using PCA and SVD (주성분 분석과 비정칙치 분해를 이용한 문서 요약)

  • Lee, Chang-Beom;Kim, Min-Soo;Baek, Jang-Sun;Park, Hyuk-Ro
    • The KIPS Transactions:PartB
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    • v.10B no.7
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    • pp.725-734
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    • 2003
  • In this paper, we propose the text summarization method using PCA (Principal Component Analysis) and SVD (Singular Value Decomposition). The proposed method presents a summary by extracting significant sentences based on the distances between thematic words and sentences. To extract thematic words, we use both word frequency and co-occurence information that result from performing PCA. To extract significant sentences, we exploit Euclidean distances between thematic word vectors and sentence vectors that result from carrying out SVD. Experimental results using newspaper articles show that the proposed method is superior to the method using either word frequency or only PCA.

The usability of the image according to the frequency encoding gradient direction conversion in fixation using the non magnetic metal screw (비 자성 금속 screw를 이용한 고정술에서 주파수 부호화 경사 방향 변환에 따른 영상의 유용성)

  • Cho, Jae-Hwan;Lee, Hae-Kag;Park, Cheol-So
    • Journal of Digital Contents Society
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    • v.12 no.1
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    • pp.49-55
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    • 2011
  • Because of causing the geometrical transformation of the magnetic field, the patient implementing the fixation using the nonmagnetic metal screw causes the magnetic susceptibility artifact at an image. Thus, in this research, the distortion measure of the image according to the frequency oblique direction conversion tried to be compared in the magnetic susceptibility artifact occurence. First, the itself phantom inserting the nonmagnetic metal screw of the titanium component was made and the region of interest was set up and the frequency oblique direction the anterior - back side was converted to the right-to-left direction in the axial image and a right-to-left was converted to the upper side - bottom side in the coronal plane and the upper - bottom side was converted to the anterior - back side in the sagittal plane and the distortion measure of the region of interest was compared, it observed. In a result, when converting the frequency oblique direction, the distortion difference of the region of interest could be confirmed and it is considered to enhance the diagnostics efficiency changing the oblique direction appropriately.

Development of Risk Assesment Index for Construction Safety Using Statistical Data (통계자료를 활용한 건설안전 위험도 평가지수 개발)

  • Park, Hwan-Pyo;Han, Jae-Goo
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.4
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    • pp.361-371
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    • 2019
  • In 2017, the ratio of the number of victims and deaths in the construction industry was the highest with 25.2% and 29.6%, respectively. Especially, as safety accidents at construction sites continue to increase, the economic loss is greatly increased too. Therefore, in order to prevent safety accidents in the construction work, the safety risk assessment index by type of construction was developed, and the main results of this study are as follows. First, 17 factors related to safety accidents at construction sites were derived through survey and interview survey, and this study suggested 9 items(process, type of construction, progress rate, contract amount, number of floors, safety education, working days and weather) throughout the expert advisory meeting. Second, the risk assessment index for safety accidents was developed based on the ratio and intensity of safety accidents. Third, to verify the risk assessment model, the construction safety risk assessment index by type of construction was derived by surveying and analyzing the statistics of the construction accident. In addition, the risk strength was calculated by dividing human damage caused by construction safety accidents into those killed and injured. The risk assessment index based on the frequency and intensity of safety accidents by type of construction is expected to be utilized as basic data when assessing the risk of similar projects in the future.

Analysis of Traffic Accident Reduction Effects considering Monitoring Direction of Traffic Camera (교통단속카메라 전·후방을 고려한 사고 저감효과 분석 -울산시 북구를 대상으로-)

  • Won, Jin-Young;Shin, Jin-Dong;Pak, So-Yeon;Lee, Jong-Seol
    • International Journal of Highway Engineering
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    • v.20 no.1
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    • pp.127-135
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    • 2018
  • PURPOSES : Traffic cameras have been installed to reduce traffic accidents. The effectiveness of traffic cameras has been proved by dozens of studies, but recently questions over its effectiveness have been raised by a series of studies. In this study, the effectiveness of traffic cameras was analyzed with a focus on different road environments. METHODS : The effectiveness of the traffic cameras was analyzed by extracting the occurence frequency before and after camera installation. The effect of reduction was analyzed comprehensively considering the installation position, monitoring direction, and surrounding environment of traffic cameras. RESULTS : The result of this study is as follows. First, the installation of cameras in an area with relatively low accidental traffic was more effective. Secondly, the effect of camera installation on car-to-pedestrian collisions was better than that of car-to-car collisions. Thirdly, accidents tended to occur more frequently when cameras were installed in front of the accident-prone owing to the negative spill-over effect. CONCLUSIONS : The result can be used to guide placement of traffic cameras. Moreover, the installation of cameras with consideration of the road environment is expected to contribute to a reduction in traffic fatalities.

Studies on the Occurence of Reproductive Disorders of Dairy Cattle Resident in High-land (고지사육유우의 번식장해 발생상태에 관한 조사연구)

  • 박춘근;고광두
    • Korean Journal of Animal Reproduction
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    • v.10 no.1
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    • pp.9-18
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    • 1986
  • Breeding and infertility status of Holstein cows reared in pasture of High-land was investigated. The results obtained were summarized as follows; 1. Eight hundred and forty Holstein cows with heifers (12.4%), 3 years old cows (19.3), 4 years old cows (16.7%), 5 years old cows (12.5%), 6 years old cows (11.4%), 7 years old cows (13.2%), 8 years old cows (9.4%) and above 9 years old cows (5.1%) were investigated. 2. They were 72.4% of conceived cows, 8.2% of uncertain pregnancy, 7.7% of physiological empty and 11.7% of reproductive disorder. 3. The percentage of cow concepted with 1, 2, 3 and more than 4 times of A.I. was 49.2, 28.8, 14.6 and 7.4% respectively. 4. In the nutritional condition of infertile cows, excellent, good, fair and poor was 7.1, 30.6, 36.7 and 25.5%, respectively. 5. Among 98 infertile cows, distribution of reproductive disorder was 41.8, 37.8, 5.1, 5.1 and 11.2% in ovary, uterus, vagina, oviduct and others, respectively. Ovary showed higher percentage than any other reproductive organs. Among the ovarian syndromes, lutein cystic ovary, follicular cystic ovary, and persistent corpus luteum were 31.7, 26.8 and 19.5%, respectively. 6. Four years old cow showed highest distribution (16.4%) among the aged groups in disordered cows. In the syndromes of reproductive disorder, latent endometritis showed higher frequency (14.3%) than any others. 7. Infertile cows with complex syncrome of genital disease was 29.6%.

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The Clinical Study of Urticaria (두드러기 치료 조사)

  • Yoon, Jung-won;Yoon, So-won;Yoon, Hwa-jung;Ko, Woo-shin
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.16 no.2
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    • pp.152-176
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    • 2003
  • This study was clinically performed with the 73 outpatients of urticaria who had visited the Dept. of Dermartology, Oriental Medical Hospital, Dong-eui University from January 1st 2000 to June 30th 2003. They have all taken the oriental herb medicine as Sungmagalguntanggamibang(SGT, 升麻葛根湯加味方) more than 1 time. Urticaria is a common disease and a well known reaction pattern of the skin charaterized by erythema, wheals and edema, that is the results of various causes. Urticaria is classified into acute or chronic type. The etilogy of acute uricaria has been determined in many cases, but the cause of chronic urticaria has been determined in 10$\%$ to 20$\%$ of cases. Character of chronic type urticaria is recurrent pruritus and erythematous skin disease by stimulating factor. Through checking up the present patient state, we verified the effect of SGT in various ways. The results were summarized as follows; 1. An increase of taking a medicine(SGT) and attending a hospital in number let down repeated urticaria occurence. 2. SGT is more effective when the symptoms with the severe pruritic wheals are spread on the whole body in daily occurrence. 3. In urticaria treatment method, gradually reducing a western medicine and going side by side SGT, that is good at symptoms improvement. 4. Etiology of urticaria is classified into intestine-stomach accumulated heat by indigestion(食滯腸胃積熱), wind-moisture(風濕), wind-heat(風熱) etc. The SGT is available in the order of frequency of use.

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Analysis of Red Tide Hot Spots in the South Sea of Gyeongnam Province Using the GOCI Images of COMS (천리안 GOCI영상을 이용한 남해안 적조우심해역 분석)

  • Kim, Dong Gyu;Jung, Yong Han;Yoo, Hwan Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.5
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    • pp.353-361
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    • 2015
  • The area of red tides occurences, which brings enormous damages every year, have been expanded to the coastal waters across the nation. Regarding to this trend, the development of red tide detection technology by using the GOCI (Geostationary Ocean Color Imager) of COMS lauched in 2010 has been drawn attentions of researchers. This study purposed on analyzing the frequency and density of red tides occurence by using the GOCI for detecting the southern sea, whereas targeted area. The observation has brought over the last three years (2012, 2013, and 2014) before the analysis was conducted. Followingly, the study could be resulted in extracting and revealing the hot spots of the red tides from two of analysis in the overlay and density. The distribution patterns of red tide occurrences according to those observed years has been shown in irregular characteristics and various changes. However, the analysis of hot spots, based on the frequency of the red tide occurrence, has revealed that the frequency of red tide occurences is continuously increased in the specific sea area. Therefore, it is concluded in that the continuous monitoring can contribute to predict accurate movements of red tides, so as establish systematic plans for preventing disasters.

A STATISTICAL STUDY OF THE MAXILLOFACIAL DISEASES BY RADIOGRAMS (X-선상에 이한 악안면질환의 통계학적 고찰)

  • Chung Yoo Taik
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.4 no.1
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    • pp.45-57
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    • 1974
  • This report based on 300 cases of serious diseases in maxillofacial region by radiograms seen at the department of dental radiodontics, infirmary school of dentistry, Kyung Hee University from October 1971 to August 1974. The maxillofacial diseases were analysed upon the following items, such as 1) the frequency of dominant diseases, 2) sex-ratio of male to female, 3) predominant region of diseases, 4) comparison with the age, 5) the incidence of diseases in relative to the individual teeth. The results were obtained as follows. 1) Among the total of 300 cases of the patients, the frequency of dominant diseases of patients were fractures of facial bone (44.3±2.87%), inflammatory diseases (22.7±2.39%), cysts (11.1±1.62%), tumors (10.7±1.77%), maxillary sinusitis (7.9±1.56%), temporomandibular joint disorders(3.3±1.05%) in the order. 2) The ex-ratio of male to female in occurence of jaw fractures were 7.3:1, temporomandibular joint disorders were 2.1:1, inflammatory diseases were 1.8:1, maxillary sinusitis were 1.7:1, but tumors were equal to 1:1, while cysts were 1:1.2 in sex difference. 3) The predominant region of mandibular fractures were symphysis(17.3±3.27%), canine region (15.0±3.09%), and angle region (14.3:±3.04%) in the order. Inflammatory diseases were occured frequently in mandible and it's left side were a little dominant. Odontogenic cysts were observed frequently in maxilla, but regardless of right and left. Carcinomas were involved most frequently in maxilla, while sarcomas and ameloblastomas in mandible. Frequency of the maxillary sinusitis were dominant right side and molar area, also temporomandibular joint disorders were right side. 4) To study comparison with the age jaw fractures showed the highest ratio at the 2nd decade(32.3±4.06%), and 3rd decade (27.8±3.89%), 4th decade (19.6±3.44%), 6th decade (9.0±2.47%), 5th decade(6.0±2.06%), 1st decade (5.3±1.95%) in the order. But 7th decade were not involved entirely. Frequency of the inflammatory diseases were the highest in the age group of 3rd decade (28.0±5.44%), and those of cysts were 5th decade (24.2±7.22%), temporomandibular joint disorders were 3rd decade (60.0±15.49%). Tumors were occured frequently over the 4th decade especially malignint tumors over the 5th decade, but maxillary sinusitis were rearless of age except for 2nd decade. 5) About the incidence of diseases in relative to individual teeth, fractures of facial bone were most frequently involved the maxillary and mandibular anterior teeth, and mandibular 3rd molar region. Cysts were maxillary anterior region inflammatory diseases were mandibular molar region maxillary sinusitis were maxillary 1st molar, region but tumors were regardless of individual teeth.

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Investigation of the Causes of Abortion and Infertility in the Swine after Consecutive Detonation into Base Rock and Use of Heavy Equipment (암반발파 및 중장비 사용후 발생한 돼지유산 및 불임증에 대한 원인 조사)

  • 김용준;조문희;조정곤;김명순
    • Journal of Veterinary Clinics
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    • v.16 no.2
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    • pp.381-388
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    • 1999
  • These investigations were performed to determine the causes of the reproductive disorders of the sows in a pig farm which was located at the distance 36m away from the detonation spot. The reproductive problems of the sows such as abortion and infertility occurred after consecutive detonation and use of heavy equipments to build 6 piers of the bridge for the expressway between Jinju and Taeieon during the period from July 1997 to October 1998. 1. The management condition of the farm, microorganism in the feed, inbreeding, hematological conditions, and viral agent causing abortion were not proved as the factors of the occurrence of abortion and infertility in the pig farm. 2. Theoretical concussion values according to the average amount of explosive per detonation were 1.16 kine for minimum amount (3.6 kg) and 3.45 kine for maximum amount(12.5 kg) of explosive, and the theoretical sound values were accordingly 92.29 decibel for minimum amount and 101.76 decibel for maximum amount of explosive, respectively, in the case of 36m distance between the detonation spot and pig farm. The frequency of detonation in a day was 7 times with interval of 15 minutes. 3. The occurence of infertility in the farm was 57.3% during the period of construction from July 1997 to August 1998. 4. In comparison of body weight of piglets between the damaged and not damaged farms, growth of piglets at the damaged farm was shown to be delayed over 30 days than those of not-damaged farm. In conclusion, abortion of 40 sows, delivery of whole still births of 22 sows, and infertility of 122 sows in the pig farm were assumed to be caused by the concussion or sound stress after consecutive detonation and use of heavy equipments.

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