• Title/Summary/Keyword: frequency-based method

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RF Seeker LOS Rate Estimation Method using Covariance and Signal Management (공분산 및 신호관리를 이용한 RF탐색기 시선각 변화율 추정기법)

  • Moon, Gwan-Young;Jun, Byung-Eul
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.4
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    • pp.292-299
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    • 2012
  • The line-of-sight(LOS) rate is estimated using Kalman filter in Radio-Frequency(RF) seeker. For the two axis gimbaled seeker, proper system modeling is considered and the basic filter structure is set up. The main issue for Kalman filter is choosing the proper process and measurement noise. For the measurement process, the signal to noise ratio(SNR) and other components are introduced. To cope with the eclipse problem or other abnormal seeker status, the pseudo input signal concept is proposed. By conditioning abnormal signals, the LOS rate estimation performance is increased. The process noise is also an important factor in the propagation phase. The analytical approach on a process noise component is performed and a reliable region for the filter is calculated based on the eigenvalue analysis. Some numerical simulations are performed to check the validity of suggested algorithm.

Comparison of Nutrient Intake between Hypercholesterolemic and Normal groups based on the 6th Korea National Health and Nutrition Examination Survey (고콜레스테롤혈증군과 정상군의 영양소 섭취량 비교: 제6기 국민건강영양조사 자료 활용)

  • Lee, Hyun-A;Kim, Hyung-Sook
    • Korean Journal of Community Nutrition
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    • v.25 no.5
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    • pp.396-405
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    • 2020
  • Objectives: This study was conducted to compare the nutrient intake of normal healthy adults with those having hypercholesterolemia. Methods: We analyzed data from the 6th Korea National Health and Nutrition Examination Survey (KNHANES VI). A total of 12,636 adults (5,223 males and 7,413 females) aged 19 or older were included in the study. Results: Males with hypercholesterolemia were older and had a higher waist circumference, body mass index, fasting blood sugar levels (FBS) and serum triglyceride (TG) concentrations compared to the normal group. Females with hypercholesterolemia were older and had higher FBS levels and serum TG concentrations compared to the normal group. While comparing nutrient intake by the 24-hour recall method, the male normal group showed a higher intake of fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), vitamin A and thiamin compared to the hypercholesterolemic group. However, the male normal group had a lower intake of iron and vitamin C compared to the hypercholesterolemic group. The female normal group had a higher intake of energy, protein, fat, SFA, MUFA, polyunsaturated fatty acids, cholesterol, riboflavin, and niacin compared to the hypercholesterolemic group, but had a lower intake of iron compared to the hypercholesterolemic group. A comparison of nutrient intake by food frequency questionnaire (FFQ) showed the following: There was no significant difference in nutrient intake between the normal men and women and those with hypercholesterolemia. After adjustment for confounding factors, nutrient intake by FFQ of the male normal group showed higher levels of n-3 fatty acid and vitamin C compared to the group with hypercholesterolemia. However, there was no significant difference in nutrient intake between the two groups of women. Conclusions: The average intake of n-3 fatty acids and vitamin C of the male group with hypercholesterolemia was lower than that of the normal group. However, since KNHANES is a cross-sectional study, prospective cohort studies are required to analyze the risk factors of hypercholesterolemia.

Current Situation Analysis of the International Marketing among Korean Apparel and Textile Firms (국내 섬유, 의류기업의 해외진출에 대한 현황분석 연구)

  • 고은주;서나현
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.9_10
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    • pp.1081-1092
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    • 2003
  • The purpose of this study was to identify the current situation of textiles and apparel firms in the overseas markets and to examine the relationship between firms' characteristic(i.e., sales volume) and international marketing strategies. A random sample of 311 textiles and apparel firms were selected. The survey design method was used to test conceptual framework. Adjusted response rate was 33.4%(n=115). Descriptive analysis (i.e., frequency, percent) and $\chi$$^2$-test were used for data analysis. About the current situation of textiles and apparel firms in the overseas markets, the motivation for international market entry was highly found to expand their operation from domestic to international market, and most firms were found to be involved with OEMs(Original Equipment Manufacturers) as an entry mode for international market. China and US market were the most popular market among Korean textiles and apparel firms. Product differentiation strategy, pricing strategy based on manufacturing cost and buyer's offering price, place strategy using foreign buyers and participating a few international exhibition were frequently used among Korean textiles and apparel firms for international marketing. Among textile firms, sales volume was related to product strategies(product development), price strategy(buyer's offer) and place strategy(channel). Among apparel firms, product strategy(product labeling), price strategy(price satisfaction). The findings of this can be used when Korean textiles and apparel firms do strategic planning and evaluate the international marketing strategies. Also information and results of this study may assist policy makers to develop better ideas and strategies for textiles and apparel industry.

Dynamic Performance Evaluation of New Type PSC Railroad Bridges (신형식 PSC 철도교량의 동적성능 평가)

  • Choi, Sanghyun
    • Journal of the Society of Disaster Information
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    • v.7 no.4
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    • pp.259-265
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    • 2011
  • After the commercial opening of the KTX in 2005, the high speed railroad has been rapidly emerged as the major transportation means due to its high energy efficiency. Recently, the government has announced its plan to build the future transportation system around the high speed railroad. Based on this policy, the existing lines as well as the lines under construction or design are planning to increase design speed. In this paper, the suitability of the mid-span PSC girder bridges for the high speed railroad is evaluated via dynamic analysis. IT, Precom, and WPC girder bridges are considered for the purpose of this study and, for comparison, the identical modeling method and the analysis technique are utilized. The performance indices used for dynamic performance evaluation are the natural frequency, the vertical displacement, the end axial displacement, track irregularity, etc. The KTX train is utilized as a dynamic load, and the dynamic analysis is performed up to the train speed of 420km/hr with the increment of 10km/hr.

A Study on the evaluation method of the design (인지패닉 상황에서의 디자인 사용성 평가 방법에 관한 연구)

  • 최인환
    • Archives of design research
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    • v.15 no.1
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    • pp.225-233
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    • 2002
  • People's thinking and aging ways, which are spread in the abnormal situation called the reoognition panic, are different from those in the normal situation. So the design which is applied to this situation have the different points to be considered. The design in the abnormal situation is as important as that in the normal situation. This study is to evaluate the basic usability of the icons which are applied to this situation. The basic data about the recognition course, icon and metaphor have been collected and analyzed, and then the experiments based on this have been planned. The proprieties and conclusions about the ways have been generalized through accomplishing and analyzing the planned experiments. The most important meaning of this study is to suggest the examples of the usability estimating ways of the design works in the abnormal situation where the recognition panic may happen with high frequency. I hope that this study will be used for checking and improving in advance the difficulties of using the design which may happen in the real situation, by using actively the similar ways to this experiment.

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The Development of Contents Systems on Major Course Materials for Technical College in Electric-Electronic Field (전문대학(專門大學) 전기.전자분야(電氣.電子分野) 전공교과(專攻敎科)의 컨텐츠 체제(體制) 개발(開發) 방향(方向))

  • Kim Sun-Tae;Rho Tae-Cheon;Kim Choon-Gil
    • Journal of Engineering Education Research
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    • v.5 no.2
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    • pp.22-35
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    • 2002
  • The main purpose of this study is to prepare an outline for developing the Contents Systems that achieve self-study systems to make the students adopt themselves into new study atmosphere and maximize the result of study on technical college in Electric-Electronic field. Questionnaire posed to analyze the demand of teaching materials to the students, and professors and also to find characteristics of students in technical college. The SPSSWIN/PC+ statistics Package was used to assay the collected answers. And simple frequency with percentage, average, and standard deviation were calculated to check the entire trend and actual state of each question. The primary outcomes of this study are as follows i) The students in the technical college prefer self-directed learning to lecturer-oriented teaching. ii) It is difficult to offer the technical college students normal education systems since the students?interest and motivation towards study are very low. iii) The lack of capability of foreign language and basic mathematics are considered as obstacles for many students technical college to study. iv) The professors in technical college still depend on traditional method to teach the students without organized research of the intellectual levels and attitude the students. v) Teaching materials in currently use are not appropriated to induce the motivation and interest of study from the students. Also, the teaching materials in use now were discovered not to have enough originality, practical application, andwere text based. Therefore, the improvement of the existing teaching materials was demanded while the fundamental ability to study of general students is declining. Consequently, it is necessary to introduce new teaching materials which are simple, easy, and organized to offer the studen ts study desire and interest.

An implementation of NDIR type $CO_2$ gas sample chamber and measuring hardware for capnograph system in consideration of the time response characteristics (시간응답특성을 고려한 2광원 1센서 방식의 capnograph 시스템용 NDIR식 $CO_2$ 가스 챔버 설계 및 측정 회로의 구현)

  • Park, I.Y.;Lee, I.K.;Lee, S.K.;Kang, K.M.;Kang, S.W.;Cho, J.H.
    • Journal of Sensor Science and Technology
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    • v.10 no.5
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    • pp.279-285
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    • 2001
  • The capnograph system for determining the partial pressure of carbon dioxide in the blood of a patient was developed based on the NDIR(non-dispersive infrared) absorption technology. NDIR gas analyzing method requires an optical absorption chamber and signal processing hardware. In this paper, we have designed and implemented NDIR type $CO_2$ gas chamber in consideration of the time response characteristics and lamp chopping frequency. And we have implemented signal processing hardware using two infrared sources to reduce the thermal background effect. The implemented gas chamber and signal processing hardware were tested in the temperature variation experiment and human expiratory experiment. The results showed that the system could produce a stable output signal and a good $CO_2$ gas concentration curve like a typical capnogram.

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The Change of Korean Men's Fashion from the 1960s to the 1990s - A Study Based on the Content Analysis of Magazine Advertisements and Pictorials -

  • Kwon, Hae-Sook;Kwon, Hae-Wook
    • Journal of Fashion Business
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    • v.10 no.3
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    • pp.31-43
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    • 2006
  • The purpose of this study is to investigate the changes of modern Korean men's fashion from the 1960s to the 1990s by reviewing fashion magazine advertisements and pictorials. For theoretical study, the characteristics and the importance of apparel advertisements and the changes of modern Korean men's fashion trend were reviewed. On the basis of the theoretical investigation, this study analyzed 932 pictorials from Joongang Magazine, Shin Dong-A, Bokjangwolbo, Meot, Men's Life, WWD, and S.F.F.A's photograph album, published from 1962 to 1998. Content analysis method was used to analyze the content of magazines and pictorials. The 932 samples are classified into apparel types, silhouette, pattern, color, type of breasts, shape of collar, number of button, type of inner wear. Frequency and $x^2$-test were conducted using a SAS statistics package to analyse the data. The results were as follows. The two-piece style prevailed in men's wear during the 60s, 70s, and 90s, while separate style prevailed during the 80s. H silhouette was the most popular during the 60s, 70s and 90s, however, X silhouette dominated the 70s. For patterns, solids were most frequently used throughout the whole 4 decades. In colors, gray was most frequently used during the 60s, and multi color was most frequently used during the 70s, 80s, and 90s. Throughout the whole decades, single breast, tailored collar, two buttons, and dress shirts were the most prevalent styles.

Analysis of the Five Major Crime Utilizing the Correlation·Regression Analysis with GIS (GIS와 상관·회귀분석을 활용한 5대 범죄의 특성분석)

  • Kim, Chang Kuy;Kang, In Joon;Park, Dong Hyun;Kim, Sang Seok
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.3
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    • pp.71-77
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    • 2014
  • People in the modern society want to live under safe and comfortable circumstances. As our society, however, is sharply developing, crimes are getting smarter and more difficult to treat. Above all, they often take place around us, and we are trying to cope with them variously in order to make our lives more comfortable and safer. In particular, five major crimes(Murde, Robber, Rape, Violence, Theft ) that most frequently occur in the real life are very threatening and fearful so it is necessary to deal with them with "the scientific method." In this study, therefore, we searched the frequency of crime by its type and analyzed spatial characteristics between crimes and criminal factors by using regression analysis and correlation analysis based on the crime data that has occurred around Geumjeng-gu, Busan so that we can confront five major crimes.

A Study on the Improvement of Driving Stability for the Motorized Manual Wheelchair INMEL-VII (전동화 수동 휠체어 INMEL-VII의 주행 안정성 개선에 관한 연구)

  • Jeong, Dong-Myeong;Go, Su-Bok;Kim, Ju-Myeong
    • Journal of Biomedical Engineering Research
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    • v.16 no.4
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    • pp.543-554
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    • 1995
  • This paper describes the improvement of driving stability and the control system for INMEL-VII which is motorized manual wheelchair to satisfy requirements of the disabled The INMEL-VI was based on high maneuverability of the omnidirection drive and safety But the results of field tests about two years showed some problems to the disabled in daily life such as driving stability, Pm switching noise, and rotation of motor without driving command on negative slope. To solve the problems due to an increased DC motor power and applied to direct connection method in INMEL- VII. It improved the driving circuits and set switching frequency to 5KHz to eliminate the switching noise caused by PWM control of DC motor, As compare with the INMEL-VI, INMEL-VII is improved in driving stability by transfer the weight center to forward. The results of field testing proved the improvement of the driving stability and software algorithm It has been estimated to have a hlgh practical use for powered walking aids to the disabled's daily life.

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