• 제목/요약/키워드: Time Studies

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Asian Stock Markets Analysis: The New Evidence from Time-Varying Coefficient Autoregressive Model

  • HONGSAKULVASU, Napon;LIAMMUKDA, Asama
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.95-104
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    • 2020
  • In financial economics studies, the autoregressive model has been a workhorse for a long time. However, the model has a fixed value on every parameter and requires the stationarity assumptions. Time-varying coefficient autoregressive model that we use in this paper offers some desirable benefits over the traditional model such as the parameters are allowed to be varied over-time and can be applies to non-stationary financial data. This paper provides the Monte Carlo simulation studies which show that the model can capture the dynamic movement of parameters very well, even though, there are some sudden changes or jumps. For the daily data from January 1, 2015 to February 12, 2020, our paper provides the empirical studies that Thailand, Taiwan and Tokyo Stock market Index can be explained very well by the time-varying coefficient autoregressive model with lag order one while South Korea's stock index can be explained by the model with lag order three. We show that the model can unveil the non-linear shape of the estimated mean. We employ GJR-GARCH in the condition variance equation and found the evidences that the negative shocks have more impact on market's volatility than the positive shock in the case of South Korea and Tokyo.

직장인의 시간관리행동과 시간관리만족도 연구 (Workers' Time Management Behaviors and Time management Satisfaction)

  • 채화영;이기영
    • 가족자원경영과 정책
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    • 제9권3호
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    • pp.31-43
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    • 2005
  • The purposes of this study were to (1) examine the sub-dimensions of time management behaviors and satisfaction with time management, and (2) to identify the variables that can affect satisfaction with time management. Data was collected through an Internet survey answered by 611 working men and women. The data were analyzed using descriptive statistics, factor analysis, and multiple linear regression analysis. As a result of the study, the sub-dimensions of time management behaviour were extracted into three subordinate categories, which were, planning, human relation orientation, and urgency. The sub-dimensions of the satisfaction with time management were extracted into three subordinate categories, which were, satisfaction with the management results, satisfaction with time distribution, and satisfaction of spare time. Management result satisfaction displayed a positive relationship with planning and work time. The satisfaction with time distribution displayed a positively relationship with planning, relations-intention, the level of education, and sleeping time, while displaying a negative relationship with work time. Also, Women tended to be more satisfied with time distribution than men. Finally, the satisfaction of spare time was positively related with age, while negatively related to urgency and work time.

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한약재 약욕요법이 소아 발열기간에 미치는 영향 : 체계적 문헌고찰 및 메타분석 (Effect of Herbal Bath for Duration of Pediatric Fever : a Systematic Review and Meta-analysis)

  • 김예지;박소현;서혜선;박슬기;이선행;이진용
    • 대한한방소아과학회지
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    • 제35권3호
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    • pp.53-66
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    • 2021
  • Objective The purpose of this study is to evaluate whether herbal bath shortens the duration of pediatric fever. Methods Databases, such as Medline, EMBASE, Cochrane library, OASIS, KISS, KMBASE, CNKI, Wanfang Med Online were used to search randomized controlled trials. Those trials that included children younger than 18-year-old were evaluated for the clinical efficacy of herbal bath in fever by analyzing 'body temperature (BT) drop start time' and 'time to return to normal BT'. Results 12 studies or 1306 participants were analyzed in the study. When applying herbal bath in combination with the controlled treatment, 'BT drop start time' was decreased by 0.11 hours, and 'time to return to normal BT' was decreased by 10.94 hours compared to the controlled group. When comparing herbal bath with tepid bath, 'time to return to normal BT' was reduced by 8.19 hours in herbal bath group. In regards to safety, 3 studies out of 12 studies mentioned about its adverse events: 2 studies did not have any adverse events, and a minor needle-shaped bleeding had occurred in one of the studies. Conclusion Use of herbal bath as a treatment of fever in children was associated with shortened duration of fever. However, cautious interpretation is necessary due to its limited safety data.

How Can We Erase States Inside a Black Hole?

  • Hwang, Junha;Park, Hyosub;Yeom, Dong-han;Zoe, Heeseung
    • Journal of the Korean Physical Society
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    • 제73권10호
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    • pp.1420-1430
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    • 2018
  • We investigate an entangled system, which is analogous to a composite system of a black hole and Hawking radiation. If Hawking radiation is well approximated by an outgoing particle generated from pair creation around the black hole, such a pair creation increases the total number of states. There should be a unitary mechanism to reduce the number of states inside the horizon for black hole evaporation. Because the infalling antiparticle has negative energy, as long as the infalling antiparticle finds its partner such that the two particles form a separable state, one can trace out such a zero energy system by maintaining unitarity. In this paper, based on some toy model calculations, we show that such a unitary tracing-out process is only possible before the Page time while it is impossible after the Page time. Hence, after the Page time, if we assume that the process is unitary and the Hawking pair forms a separable state, the internal number of states will monotonically increase, which is supported by the Almheiri-Marolf-Polchinski-Sully (AMPS) argument. In addition, the Hawking particles cannot generate randomness of the entire system; hence, the entanglement entropy cannot reach its maximum. Based on these results, we modify the correct form of the Page curve for the remnant picture. The most important conclusion is this: if we assume unitarity, semi-classical quantum field theory, and general relativity, then the black hole should violate the Bekenstein-Hawking entropy bound around the Page time at the latest; hence, the infinite production arguments for remnants might be applied for semi-classical black holes, which seems very problematic.

대학 교양수학에서 수업시간대와 학업성취도의 관계 연구 (A Study on the Relationship between Lecture Time and Academic Achievement in College Mathematics Courses)

  • 나광수;김동호;김재덕;심호진;문은호
    • 공학교육연구
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    • 제22권3호
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    • pp.41-48
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    • 2019
  • The purpose of this study is to examine how academic achievement in college math courses differ depending on when the course takes place. As a result, based on years of data analyses on students' academic achievement, it was affirmed that achievement levels differ due to environmental factors despite the diverse efforts of instructors and students. By further analyzing the causes of these differences, this study suggests solutions for improving the different academic achievement levels.

뇌졸중 환자를 위한 물리치료 강도 (Intensity of Physical Therapy for Stroke)

  • 신재욱;김재용;김좌준
    • PNF and Movement
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    • 제11권1호
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    • pp.35-42
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    • 2013
  • Purpose : This paper reviews intensity of physical therapy for stroke. Methods : This is literature study with Pubmed, EBSCO, ProQuest, EMBASE and CINAHL. Results : There were 20 studies that reviewed effects of increased intensity of physical therapy after stroke involving time post-stroke, elements of physical therapy, duration of physical therapy, methods of physical therapy. Ten of the eleven studies, involving time post-stroke, demonstrated significant improvement. Seventeen studies involving upper extremity, lower extremity and mobility demonstrated significant improvement. Five studies involving increased duration of physical therapy demonstrated significant improvement. Studies involving methods of physical therapy showed that mix of different methods is more effective than single method. Conclusion : Increased intensity of physical therapy improve functional recovery.

대학생의 시간매트릭스 사용과 시간관리 행동 (College Students' Time Management Behavior Using the Time-Matrix)

  • 서인주;두경자
    • 대한가정학회지
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    • 제47권8호
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    • pp.13-24
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    • 2009
  • This study investigated college students' time management behavior and time satisfaction according to the use of the time-matrix. Data were collected from 400 college students in Seoul by a self-administered questionnaire. Collected data were subjected to descriptive and comparative statistical analyses using the software SPSS(version 12.0). The conclusions of this study were as follows; 1. The use of time-matrix was categorized into 4 task groups: (1) not urgent but important, (2) urgent but notimportant, (3) neither urgent nor important, (4) urgent and important. 2. Time-management-behavior of planning was categorized into 3 components: standard setting, reality overlapping and implementing into 3 components(i.e., checking, adjusting, facilitating condition). 3. In all domains except overlapping, 'not urgent but importance' was the most popular managerial behavior. 4. However, 'neither urgent nor important' was voted the most popular in terms of managerial satisfaction. This study provides useful knowledge on managerial time-use categorization. Furthermore also contributes towards the knowledge base of time-managerial behaviors and dispels stereotypical-thinking that only bing busy all the time using is an indication of good time management behavior. Finally, this study advocates use of the time-matrix to achieve efficient time management.

Characteristics of Warm Acupuncture Reported in Experimental Studies: A Descriptive Narrative Review

  • Choi, Ji Won;Choi, Seo Young;Lee, Ji Sun;Yang, Gi Young
    • Journal of Acupuncture Research
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    • 제36권3호
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    • pp.131-139
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    • 2019
  • Background: This study aimed to investigate the correlation between heat transmission and intervention factors for warm acupuncture (such as features of acupuncture material and moxa, the treatment method, and clinical symptoms). Methods: Korean, English, Chinese and Japanese databases were analysed. Experimental studies that explored the association between thermal stimulation delivery and warm acupuncture intervention factors were included. The peak temperature, time to reach the peak temperature, and time of the effective stimulus, were set as the major parameters and analysed. Results: A total of 12 studies were included. Two studies were associated with the acupuncture needle material, 4 studies associated with the moxa mass, 1 study associated with the moxa density, 2 studies associated with the location of ignition, and 1 study associated with treatment environment were reviewed. The reporting quality of the 12 studies was low. Conclusion: This study provided limited information because of the heterogeneity of materials and parameters depending on each experiment. Further studies should clarify the correlation between heat transmission and intervention factors for warm acupuncture.

요골신경마비의 한의학적 치료에 대한 연구 고찰 (Review of the Studies on Korean Medicine Treatment of Radial Nerve Palsy)

  • 현재철;정수현
    • 척추신경추나의학회지
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    • 제14권2호
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    • pp.43-54
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    • 2019
  • Objectives : The purpose of this study was to assess the use of Korean medicine for treating radial nerve palsy. Methods : We searched for studies on the use of Korean medicine for the treatment of radial nerve palsy in 7 electronic databases and analyzed these studies. Results : We found 95 studies on radial nerve palsy from 7 electronic databases. We excluded 77 duplicate studies, 1 review article and 2 studies published before 2000. As a result, 15 case studies(36 patients) were included. Acupuncture(15 times), electroacupuncture(6 times), pharmacopuncture(9 times), herbal medicine(11 times), physical therapy(10 times), moxibustion(3 times), cupping therapy(1 time), chuna manual therapy(1 time) and yinyang balancing appliance(1 time) were used. LI11 for acupuncture, LI4, LI11 for electroacupuncture, bee venom as pharmacopuncture material and LI4, LI10, LI11 in pharmacopuncture point, Boik-tang gami as herbal medicine, hot pack for physical therapy, LI4, LI11 for moxibustion were the most frequently used. Conclusions : Korean medicine treatment for radial nerve palsy has been performed in various ways. However, we found limited evidence regarding Korean medicine for radial nerve palsy. Thus, we think various types of studies including more case reports, for radial nerve palsy should be performed in the future.