• Title/Summary/Keyword: Time-Frequency Analysis

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Consumer Characteristics Relating to Business Jacket Practices -Focus on Working Women in the U.S.- (미국 직장여성들의 비지니스 쟈켓 착용과 관련된 소비자 특성 분석)

  • Yoo, Seul-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.12 s.159
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    • pp.1649-1660
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    • 2006
  • IIn the United States, professional dress codes for working women have changed over time since the 1970s. Considering the changes, from conservative and traditional business uniforms in the 1970s, business casual in the late 1980s through 1990s, and the current revival of tailored business suits, this study investigated working women's business jacket practices and their association with personal, psycho-social, and physical characteristics. Working women's job satisfaction and corporate culture were also examined in relation to business jacket practices. Research data were collected by implementing mail surveys to 1,500 randomly selected working women in the United States. Of the 1,500 distributed questionnaires, a total of 312 were returned, of which 265 were deemed usable, yielding a 20.8% response rate. For data analysis, descriptive statistics, such as frequency, percentage distribution, mean scores, standard deviations, and Canonical Correlation were tabulated. The respondents ranged in age from 22 to 65. The mean age of the respondents was 44 years(SD=9.63). Most respondents were married(77.4%), working full-time(81.4%), career-oriented (77.2%), Caucasian(89.8%), had at least one child(78.9%), and had a professional job(75.9%). Working women's age, number of children, self-confidence in dressing, perceived importance of clothing, body frame size, and visibility to superiors and public were positively associated with business jacket practices, while age of first child, family size, dress size, and job satisfaction were negatively associated with business jacket practices.

Examination of the Physical Environmental Readiness for Smart Learning in Special Schools and Classes and the Actual Utilization of Smart Devices by Special Education Teachers (특수학교 및 특수학급의 스마트교육 환경 조성 및 특수교사의 스마트기기 활용 실태)

  • Kim, Jung-Soo;Kim, Suk-Jin
    • The Journal of the Korea Contents Association
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    • v.18 no.10
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    • pp.415-424
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    • 2018
  • The purpose of this study was to examine the physical environmental readiness for smart learning and the actual utilization of smart devices by special education teachers, and to suggest ways to vitalize smart education. For this, a 14-item survey questionnaire was developed, which touched upon issues regarding the availability of wireless internet service and teachers' utilization of smart devices. An online survey was conducted among a randomly chosen sample of 991 special education teachers across the nation, including teachers who work at special schools for developmentally disabled students and in special classes at all three levels of regular schools.The collected data was analyzed with the method of a cross-time-frequency analysis using a SPSS 21.0 statistics program. The research findings indicated that both special schools and classes had a poor smart education environment and that special education teachers were having a harding time because of the lack of the infrastructure and additional expenses. In addition, special education teachers were found to use smart device mostly for the purpose of motivating students. These research findings propose that it is urgent to set up a proper smart education environment for special needs students and to provide a systematic training program for special education teachers.

Prediction of Time to Corrosion for Concrete Bridge Decks Exposed to De-Icing Chemicals (제빙화학제 살포로 인한 콘크리트 교량 바닥판의 철근부식 시작시기의 예측)

  • Lee, Chang-Soo;Yoon, In-Seok;Park, Jong-Hyok
    • Journal of the Korea Concrete Institute
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    • v.15 no.4
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    • pp.606-614
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    • 2003
  • The major cause of deterioration for the concrete bridge decks exposed to de-icing chemicals would be chloride-induced reinforcement corrosion. Thus, in this paper, in order to predict time to corrosion for concrete bridge decks in the urban area, chloride concentration was measured with depth from the surface. A frequency analysis on surface chloride concentration and chloride diffusion coefficient of concrete bridge deck equals 0.192, 29.828 in the scale parameter and 7.899, 1.983 in the shape parameter of gamma distribution. The average value of surface chloride concentration equals 1.5 kg/㎥ and condenses from 1 to 2 kg/㎥ in the level of probability 70%. From the probabilistic results, it is confirmed that 26mm of minimum cover depth in order to target 20 years over is calculated. The countermeasure strategy to extend the service life of concrete bridge deck exposed to de-icing chemicals would be an effective method to increase cover depth and to place high performance concrete, which could lead to reduce the chloride diffusion coefficient and distribution range.

Erectile Dysfunction in Patients with Chronic Obstructive Pulmonary Disease (만성폐쇄성폐질환 환자에서 발기부전)

  • Rhee, Yang Keun;Kim, Jin Ho;Lee, Heung Bum;Lee, Yong Chul;Park, Jong Kwan
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.3
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    • pp.304-310
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    • 2003
  • Background : Recent discoveries on the physiology of an erection have demonstrated that the organic causes of impotence are more common, and psychogenic impotence is correspondingly less common than was formally believed. The incidence of sexual dysfunctions in chronic obstructive pulmonary disease (COPD) patients is largely unknown or may be perfunctorily attributed to the associated illness or to aging. This study investigated whether or not the impotence was related to the COPD itself as well as whether or not it nay stem from organic causes in a notable proportion of such patients. Methods : The sexual function was evaluated in 10 COPD patients and 10 normal control subjects. A nocturnal Rigi Scan was performed to evaluate the erectile function of each group. The level of hormones such as the free testosterone, prolactin and thyroid stimulating hormone (TSH) was measured, and a pulmonary function test and arterial blood gas analysis was performed. Results : The time duration and frequency of a penile erection were significantly lower in COPD patients than the controls (p<0.05). In addition, the $PaO_2$ levels correlated with the time duration of the penile erection. Conclusion : These results suggest that COPD is one of the causes of organic erectile dysfunction.

A Study on Creation and Development of Folksonomy Tags on LibraryThing (폭소노미 태그의 생성과 성장에 관한 연구 - LibraryThing을 중심으로 -)

  • Kim, Dong-Suk;Chung, Yeon-Kyoung
    • Journal of the Korean Society for Library and Information Science
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    • v.44 no.4
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    • pp.203-230
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    • 2010
  • This study analyzed the development and growth of folksonomy by examining tags associated with 40 bestsellers on LibraryThing.com in 6-month intervals. It was found that tag values do not decrease but grow in terms of quantity and quality. Accordingly, we examined the major significances of the tags and their potential utilization as an expression of subjects. Our findings were as follows. First, the motivations for tagging can be categorized into personal information for search purposes, self-fulfillment such as sense of achievement, display of emotion and sharing of one's experience with others, or an altruistic objective that emphasizes sociality with a desire that one's actions might provide social benefits. According to our analysis, 74.12% of tags had a social motivation. Second, the total number of tags and the frequency of usage increased with time. Third, the categories that showed a high increase in tag usage were dates of publication and reading, key words, main characters, and book reviews. Tags related to subjects had the highest ratio. Fourth, among Library of Congress Subject Headings (LCSH), multiple genres, key words and main characters were assigned to books, and specific key words and other properties were added as time progressed. There was also a slight increase in the number of tags consistent with LCSH. Fifth, we found that key tags could serve as a compilation of terms that reflects the knowledge base of the corresponding era. Thus, folksonomy should be continuously monitored for its quantitative and qualitative development of the tags to make improvements on its formative disadvantages, and identify internal semantic significance, be actively utilized in conjunction with taxonomy as a flexible compilation of terms that incorporate the history of a specific era.

A study on unmanned watch system using ubiquitous sensor network technology (유비쿼터스 센서 네트워크 기술을 활용한 무인감시체계 연구)

  • Wee, Kyoum-Bok
    • Journal of National Security and Military Science
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    • s.7
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    • pp.271-303
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    • 2009
  • "Ubiquitous sensor network" definition is this-Someone attaches electro-magnetic tag everything which needs communication between man to man, man to material and material to material(Ubiquitous). By using attached every electro-magnetic tag, someone detects it's native information as well as environmental information such as temperature, humidity, pollution and infiltration information(Sensor). someone connects it realtime network and manage generated information(Network). 21st century's war is joint combined operation connecting with ground, sea and air smoothly in digitalized war field, and is systematic war provided realtime information from sensor to shooter. So, it needs dramatic development on watch reconnaissance, command and control, pinpoint strike etc. Ubiquitous computing and network technologies are essential in national defense to operate 21st century style war. It is possible to use many parts such as USN combined smart dust and sensor network to protect friend unit as well as to watch enemy's deep area by unmanned reconnaissance, wearable computer upgrading soldier's operational ability and combat power dramatically, RFID which can be used material management as well as on time support. Especially, unmanned watch system using USN is core part to transit network centric military service and to get national defense efficiency which overcome the dilemma of national defense person resource reducing, and upgrade guard quality level, and improve combat power by normalizing guardian's bio rhythm. According to the test result of sensor network unmanned watch system, it needs more effort and time to stabilize because of low USN technology maturity and using maturity. In the future, USN unmanned watch system project must be decided the application scope such as application area and starting point by evaluating technology maturity and using maturity. And when you decide application scope, you must consider not only short period goal as cost reduction, soldier decrease and guard power upgrade but also long period goal as advanced defense ability strength. You must build basic infra in advance such as light cable network, frequency allocation and power facility etc. First of all, it must get budget guarantee and driving force for USN unmanned watch system project related to defense policy. You must forwarded the USN project assuming posses of operation skill as procedure, system, standard, training in advance. Operational skill posses is come from step by step application strategy such as test phase, introduction phase, spread phase, stabilization phase and also repeated test application taking example project.

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A RFID Tag Anti-Collision Algorithm Using 4-Bit Pattern Slot Allocation Method (4비트 패턴에 따른 슬롯 할당 기법을 이용한 RFID 태그 충돌 방지 알고리즘)

  • Kim, Young Back;Kim, Sung Soo;Chung, Kyung Ho;Ahn, Kwang Seon
    • Journal of Internet Computing and Services
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    • v.14 no.4
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    • pp.25-33
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    • 2013
  • The procedure of the arbitration which is the tag collision is essential because the multiple tags response simultaneously in the same frequency to the request of the Reader. This procedure is known as Anti-collision and it is a key technology in the RFID system. In this paper, we propose the 4-Bit Pattern Slot Allocation(4-BPSA) algorithm for the high-speed identification of the multiple tags. The proposed algorithm is based on the tree algorithm using the time slot and identify the tag quickly and efficiently through accurate prediction using the a slot as a 4-bit pattern according to the slot allocation scheme. Through mathematical performance analysis, We proved that the 4-BPSA is an O(n) algorithm by analyzing the worst-case time complexity and the performance of the 4-BPSA is improved compared to existing algorithms. In addition, we verified that the 4-BPSA is performed the average 0.7 times the query per the Tag through MATLAB simulation experiments with performance evaluation of the algorithm and the 4-BPSA ensure stable performance regardless of the number of the tags.

Evaluation of Fundamental Period of Rockfill Dam Using Blasting Vibration Test (발파진동실험을 이용한 사력댐의 고유주기 산정)

  • Kim, Nam-Ryong;Ha, Ik-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5C
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    • pp.185-192
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    • 2012
  • The objective of this study is to present and verify a method for evaluating the fundamental period of a rockfill dam using artificially generated vibration from a blasting event. In this study, the artificial blasting vibration tests were carried out at the site adjacent to the existing Seongdeok Dam for the first time in Korea. The artificial vibrations were induced by 4 different types of blasting with the various depths of blasting boreholes and the various explosive charge weight. During the tests, the accelerations time histories were recorded at the crest of the dam. In this acceleration history, only free vibration decay part following the main vibration event was extracted and it was analyzed by frequency domain analysis using Fast Fourier Transform (FFT). From the results of FFT, the fundamental period of the target dam was evaluated. It is found that the effect of different blasting types on the fundamental period of the target dam is negligible and the fundamental period of the target dam can be consistently obtained by blasting vibration tests. Furthermore, it is found that the period of the target dam calculated by the method using blasting vibration test is similar to that obtained by the method of previous researchers using the real earthquake records. Therefore, in case that the earthquake record is not available, the fundamental period of a rockfill dam can be reasonably evaluated if blasting vibration test is allowed at the site adjacent to the dam.

A study on job satisfaction according to clinical dental hygienists' career in Busan (부산지역 치과위생사의 근무경력에 따른 직무만족도에 관한 연구)

  • Kang, Hyun-Kyung;Kwun, Hyeon-Sook
    • Journal of Korean society of Dental Hygiene
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    • v.9 no.3
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    • pp.507-521
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    • 2009
  • This study purposed to analyze dental hygienists' job satisfaction according to their clinical career as an effort to enhance their job satisfaction and quality and to provide basic materials for dental hygienists' effective job performance. For this purpose, we surveyed 120 dental hygienists working at dental hospitals and clinics in Busan during the period from the $1^{st}$ February to $31^{st}$ March 2009 by using a self administered questionnaire. Job satisfaction was measured using a 5 point Likert scale ranging from 'Absolutely yes' (5 points) to 'Yes' (4), 'So so' (3), 'No' (2), and 'Not at all' (1), and a high score indicates high degree of satisfaction. When it testd the reliability of the job satisfaction scale was tested, Cronbach's Alpha (${\alpha}$) was 0.85 which indicates the instrument is sufficiently reliable. Data collected were analyzed with SPSS. We performed frequency analysis in order to examine the subjects' demographical characteristics, and Chi square and one way ANOVA to examine their perception of their job, job satisfaction, and their aptitude and status as a dental hygienists' according to clinical career. The results of this study were as follows. 1. The longer clinical career the dental hygienists had, the more they thought that they had aptitude as a dental hygienist (p<0.05). 2. The dental hygienists' turnover intention was different according to clinical career (p<0.01). 3. The longer clinical career the dental hygienists had, the more satisfied they were when they were working at a dental hospital or clinic equipped with convenience facilities (change room, lounge, etc.) (p<0.01). 4. The longer clinical career the dental hygienists had, the more power to make decisions they had and the more acknowledgement and trust they received from dentists (p<0.01). 5. Satisfaction with duty coordination was low in general, but it grew higher with increase in clinical career (p<0.01). 6. The longer clinical career the dental hygienists had, the more satisfied they were with patients' appreciation of their treatment (p<0.01). In addition, their time and opportunities to discuss with dentists were different according to clinical career, and their satisfaction with the items was higher when their clinical career was long (p<0.01). 7. As to their perception of dental hygienists' potential for development, they generally believed that they had potential for future growth with the expansion of their work scope (M=3.73). The longer clinical career the dental hygienists had, the more satisfied the more power to make decisions they had and the more acknowledgement and trust they received from dentists and their time and opportunities to discuss with dentists when they were working at a dental hospital or clinic equipped with convenience facilities (change room, lounge, etc.). The longer clinical career the dental hygienists had, the more they thought that they had aptitude as a dental hygienist. In conclusion, the longer clinical dental hygienists' Career had, satisfaction was able to take a highness to a dental hygienist occupation.

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Modeling of Elastodynamic Problems in Finite Solid Media (유한 고체내 탄성동역학 문제의 모델링)

  • Cho, Youn-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.2
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    • pp.138-149
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    • 2000
  • Various modeling techniques for ultrasonic wave propagation and scattering problems in finite solid media are presented. Elastodynamic boundary value problems in inhomogeneous multi-layered plate-like structures are set up for modal analysis of guided wave propagation and numerically solved to obtain dispersion curves which show propagation characteristics of guided waves. As a powerful modeling tool to overcome such numerical difficulties in wave scattering problems as the geometrical complexity and mode conversion, the Boundary Element Method(BEM) is introduced and is combined with the normal mode expansion technique to develop the hybrid BEM, an efficient technique for modeling multi mode conversion of guided wave scattering problems. Time dependent wave forms are obtained through the inverse Fourier transformation of the numerical solutions in the frequency domain. 3D BEM program development is underway to model more practical ultrasonic wave signals. Some encouraging numerical results have recently been obtained in comparison with the analytical solutions for wave propagation in a bar subjected to time harmonic longitudinal excitation. It is expected that the presented modeling techniques for elastic wave propagation and scattering can be applied to establish quantitative nondestructive evaluation techniques in various ways.

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