• Title/Summary/Keyword: circulation frequency

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Study on the Utilization Status of the Woody Landscape Plants in Korea ( I ) (우리나라의 조경공사의 조경수목 활용실태에 관한 연구(I))

  • 이동철;심경구
    • Journal of the Korean Institute of Landscape Architecture
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    • v.15 no.2
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    • pp.23-41
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    • 1987
  • This study was conducted to investigate the planting status of the woody landscape plant species and to obtain some fundamental informations for improvement of production and sales circulation of the woody landscape plants. The details of 328 landscape projects which were carried out for 2 years from 1983 to 1984 were surveyed to investigate the utilization status of the woody landscpe plants. The results obtained are summarized as fellows ; 1) The utilization rate of the trees to the shrubs as woody landscape plants was 1 : 6 and that of the evergreens to deciduous plants was 1 : 4. The plant species which were most frequently used in landscaping were Buxus microphylla koreana, Juniperus chinensis, Zelkova serrata and Acer saccharinum, howevr, plants which were used in largest quantitites were Ligustrum obtusifolium, Forsythia koreana, Buxus microphylla koreans and Rhododendron yedoense var. poukhanense. 2) The number of plants planted among 3 shrub species(Ligustrum obtusifolium, Forsythia koreana and Buxus microphylla korana) exceeded half of the total number of shrubs planted for landscping, however, the number of plants planted among 8 tree species including Pinus koreainensis were about half of the total tree species. 3) The number of government price specified plant species was only 20%, but the utilization frequency of the price specified plants was as much as 6 times than unspecified plants and 85% of plants used in landscaping works were the price specified plants. The utilization rate of the price specified plants was significantly high in the shrubs than the trees and in the evergreen than deciduous plants. 4) The amounts in use of the price specified standardized plants were significantly more than those of unstandardized plants. When the plant heights are same, the plants having wider canopy or stem diameter were rather frequently used in the landscaping works. The ratio of the width of the canopy or stem diameter to the stem length of the plants in the Korean standard is significantly greater than that in the Japanese standard.

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Characterisitcs of Hail Occurred in the Korea Peninsular (우리 나라 우박 발생일의 특성)

  • Im, Eun-Ha;Jeong, Yeong-Seon;Nam, Jae-Cheol
    • Journal of Korea Water Resources Association
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    • v.33 no.2
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    • pp.229-235
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    • 2000
  • Characteristics of hail occurred during 1989-1998 is studied. Hail is observed mainly at west coast, southwest inland, and Taegwallyong. Average diameter of hailstone is 0.6 cm, and 70% of the occurrence frequency of hail is observed at west coast. During winter and spring, the wet -bulb zero height (WBZ) is low enough to prevent the melting process of hail. But the lack of available low-level moisture (mean mixing ratio in lowest 100 hPa) makes the size of hail small. As a result, smaller size hail is observed frequently over west coast. On the contrary, WBZ is higher during summer, it means that hail is melted before it reaches ground, but the size of hail is bigger. Thus the larger hail is observed mainly Taegwallyong during summer. Hail is observed from 1100 LST to 1500 LST over west coast and around 1800 LST over Taegwallyong. It suggest that thermally driven mesoscale circulations such as land-sea breeze and mountain ridge-valley circulation aid in the formation of hail. Upper and surface air temperature is related to formation of hailstorm. Before formation of hailstorm in November 1998, the upper air temperature decreases. And hails is observed in the spot of strong temperature and dew point temperature gradient coincidently.

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Changes of Surface Temperature and Electromyography Activities by Local Heat and Cold (온열과 냉의 국소적용에 의한 체표면 온도와 근전도 활동의 변화)

  • Choi, Seok-Ju;Lim, Sang-Wan;Kim, Su-Hyon;Mun, Dal-Ju
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.5 no.2
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    • pp.61-72
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    • 2007
  • INTRODUCTION: Local heat and cold application has been frequently used as means of muscle relaxation and blood circulation or reinforcing muscle strength, relaxing muscle tension in clinical situation. In particular, it has been known that long-term heat and cold application for relaxing muscle tension inhibits muscle spasticity or tension. But, it has been rarely reported that what influences of heat and cold application on activation of muscle action potential. Therefore, this study aims to analyze surface temperature and electromyography activities according to the heat and cold application. METHODE: Subjects of this research were 10 normal men and women (5 men, 5 women). Hot pack and cold pack was applied to vastus medialis muscle of thigh and rectus femoris muscle for 20 min. Surface temperature of vastus medialis muscle and rectus femoris muscle was measured, knee joint of subjects was in $45^{\circ}$ flexion, sitting on a chair, maximal isometric contraction was induced, surface electromyography (sEMG) signals were collected and root mean square (RMS) and median frequency (MOF) were analyzed. All measurements were conducted before and immediately after experiment, 10 min., 20 min. and 30 min. after experiment. Data were analyzed with SPSS 12.0 program, comparison of changes in superficial temperature and sEMG signals through repeated measurement was conducted with repeated measures ANOVA and significance level $\alpha$ was 0.05. RESULTS: Changes of surface temperature of vastus medialis muscle according to cold application were radically decreased immediately after application, but it was recovered after 30 min. of application and it showed significant difference (F4. 36=72.216, P<0.001). Surface temperature of rectus femoris also showed radical decrease immediately after application, but it was recovered after 30 min. of application and showed significant difference (F4. 36=88.930, P<0.001). Changes of surface temperature of vastus medialis muscle according to heat application were radically increased immediately after application, but it was recovered after 30 min. of application and it showed significant difference (F4. 36=27.267, P<0.001). Surface temperature of rectus femoris also showed radical decrease immediately after application, but it was recovered after 30 min. of application and showed significant difference (F4. 36=19.774, P<0.001). Changes of sEMG by heat and cold application were no statistical difference. Surface temperature of skeletal muscle after heat and cold application showed significant change for 30 min., but it was found that increase or decrease of surface temperature had not great influence on sEMG activities.

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Online Information Sources of Coronavirus Using Webometric Big Data (코로나19 사태와 온라인 정보의 다양성 연구 - 빅데이터를 활용한 글로벌 접근법)

  • Park, Han Woo;Kim, Ji-Eun;Zhu, Yu-Peng
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.728-739
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    • 2020
  • Using webometric big data, this study examines the diversity of online information sources about the novel coronavirus causing the COVID-19 pandemic. Specifically, it focuses on some 28 countries where confirmed coronavirus cases occurred in February 2020. In the results, the online visibility of Australia, Canada, and Italy was the highest, based on their producing the most relevant information. There was a statistically significant correlation between the hit counts per country and the frequency of visiting the domains that act as information channels. Interestingly, Japan, China, and Singapore, which had a large number of confirmed cases at that time, were providing web data related to the novel coronavirus. Online sources were classified using an N-tuple helix model. The results showed that government agencies were the largest supplier of coronavirus information in cyberspace. Furthermore, the two-mode network technique revealed that media companies, university hospitals, and public healthcare centers had taken a positive attitude towards online circulation of coronavirus research and epidemic prevention information. However, semantic network analysis showed that health, school, home, and public had high centrality values. This means that people were concerned not only about personal prevention rules caused by the coronavirus outbreak, but also about response plans caused by life inconveniences and operational obstacles.

Catalog use study : with reference to universities in Daegu (대학도서관의 목록이용연구)

  • 최달현
    • Journal of Korean Library and Information Science Society
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    • v.9
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    • pp.241-266
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    • 1982
  • This paper gives a summary and overview of a survey conducted at the catalogues of five universities in Daegu during November 1982. The major objective of this study was to secure information about user needs in order to improve the catalogue in Korean university libraries. Data was collected by a combined method of questionnaire and interview. A total of 379 respondents were taken on a randomly selected sample of catalogue users. Results of the survey can be summarized as follows: 1. Eighty-eight percent of the students answered that they had used the library more than twice a month. Nevertheless the number of students consulting the catalogue with the same frequency was only 220, or a n.0, pproximately 58 percent. Those who used the library most tended to use the catalogue more than those who rarely came to the library. 2. Those who had been shown how to use their own catalogue were only 32.5percent of which the students found the instruction sufficient for them to be able to use the catalogue were only 37.5 percent. In particular, they stated that instructions by printed materials and/or library orientation were so poor that they didn't give much help in using the catalogue. This problem makes many libraries to review their own method of instruction in order to encourage patrons to use the catalogue more effectively. 3. Most of the students consulted the catalogue in order to locate library materials. Known-item searches and subject searches were 84 and 16 percent respectively. While 70.5 percent of the students used the author-title catalogue without any difficulties, only 35.5 percent of those stated that using the classed catalogue was easy. 4. It was surprising that the number of students using title access in the search was far greater than that of students using author access. In contrast with this, other studies conducted by many earlier overseas investigators revealed that the great majority of patrons tended to use the latter first. Therefore, we should put more emphasis on the title entries in the catalogue itself as well as cataloging rules. 5. Most useful bibliographic elements in the entry were author, title, call number, date and publisher whereas edition, series statement and the location of publisher were rarely used compared with the other elements. Content note was the most desirable element in the entry to be involved, for many catalogers were used not to describe it on the note area. 6. The chief reason given for not using the catalogue was "I can manage without it" with "It's difficult to understand contents of the card entry." The other one was "It's useless to search materials by the catalogue because I've failed so many times to obtain them out of the stock." In response to this, circulation and acquisition system should be improved not to make such complaints any more.

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A Study on Relationship of Computer Games and Study Achievement (컴퓨터 게임과 학업성취도와의 관계 연구)

  • Koo, Sung-Ok;Maeng, Seung Ryol;Yoo, Kwan-Hee
    • The Journal of Korean Association of Computer Education
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    • v.8 no.4
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    • pp.79-86
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    • 2005
  • Educational objectives are the most important items because not only they must be decided first in the circulation process of curriculum but also they should be the basis for the process of curriculum. The establishment of objectives is very important because it can determine success or failure of computer education. In this paper, questionnaire research is conducted and analyzed for male students of middle schools in Chungbuk province, Korea to determine that it's reasonable for computer games to be perceived negatively. The results of the research are as follows. 48% of them are represented to play computer game almost everyday, and 8% to play it scarcely. So most of students are enjoying it regardless of their grade. If students whose grades are ranked upper level start playing games, they're tend to quit it within 1 or 2 hours. And they enjoy role-playing or simulation game. In general, they do not play action games. If their grades are ranked lower level start playing games, a lot of them continue to play longer than 3 hours like game addict. And in this level, there exist students who barely play games. In middle level, there are no apparent characteristics. According to the result of the research, there is no correlation between frequency of playing games and academic achievements. So it's no problem to relieve worries if one often play computer games, his or her grade will get down. In case that the grades of students are ranked upper level, however, there are few who continue to play games longer than 3 hours.

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The Effect of Muscle Fatigue Reduction and Heart Rate Recovery According to Whole Body Vibration after Gait Exercise in the Young Female (성인여성의 보행 운동 후 전신진동이 근피로도 해소와 심박회복율에 미치는 영향)

  • Kang, Seung-Rok;Min, Jin-Young;Hong, Cheol-Un;Kwon, Tae-Kyu
    • Science of Emotion and Sensibility
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    • v.19 no.1
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    • pp.3-10
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    • 2016
  • This research was to investigate the effect of fatigue reduction and heart rate recovery (HRR) according to whole body vibration (WBV). 20 healthy participants were recruited and divided into vibration group (VG) and none vibration group (NVG). VG was group with provided vibration and NVG was group without vibration. They exercised slope gait with 8.5 degree and 4km/h during 30min. They rested on the chair type vibrator during 30min. The vibration consists of 10hz as frequency and 5mm as amplitude. We measured the lactate in the blood and HRR before, immediately after exercise and after rest session. The results showed that lactate level in VG the more decreased at 95.2%. The result of HRR was similar including recovery at 50.67% in VG. The WBV with stimulated vessel in muscle assisted the recovery function by reducing the excess post-exercise oxygen consumption (EPOC) quickly and improving blood circulation. The rest with WBV could provide efficient cool-down exercise for elderly and women without other physical activities after exercise.

Application of Objective Mapping to Surface Currents Observed by HF Radar off the Keum River Estuary (금강하구 연안에서 고주파 레이더로 관측된 표층해류에 대한 객관적 유속산출 적용)

  • Hwang, Jin-A;Lee, Sang-Ho;Choi, Byung-Joo;Kim, Chang-Soo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.1
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    • pp.14-26
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    • 2011
  • Surface currents were observed by high-frequency (HF) radars off the Keum River estuary from December 2008 to February 2009. The dataset of observed surface currents had data gaps due to the interference of electromagnetic waves and the deteriorating weather conditions. To fill the data gaps an optimal interpolation procedure was developed. The characteristics of spatial correlation in the surface currents off the Keum River estuary were investigated and the spatial data gaps were filled using the optimal interpolation. Then, the temporal and spatial distribution of the interpolated surface currents and the patterns of interpolation error were examined. The correlation coefficients between the surface currents in the coastal region were higher than 0.7 because tidal currents dominate the surface circulation. The sample data covariance matrix (C), spatially averaged covariance matrix with localization ($C^G_{sm}$) and covariance matrix fitted by an exponential function ($C_{ft}$) were used to interpolate the original dataset. The optimal interpolation filled the data gaps and suppressed the spurious data with spikes in the time series of surface current speed so that the variance of the interpolated time series was smaller than that of the original data. When the spatial data coverage was larger (smaller) than 70% of the region, the interpolation error produced by $C^G_{sm}$ ($C_{ft}$) was smaller compared with that by C.

Adaptation Capability of Reservoirs Considering Climate Change in the Han River Basin, South Korea (기후변화를 고려한 한강유역 저수지의 적응능력 평가)

  • Chung, Gunhui;Jeon, Myeonho;Kim, Hungsoo;Kim, Tae-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5B
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    • pp.439-447
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    • 2011
  • It is a main concern for sustainable development in water resources management to evaluate adaptation capability of water resources structures under the future climate conditions. This study introduced the Fuzzy Inference System (FIS) to represent the change of release and storage of reservoirs in the Han River basin corresponding to various inflows. Defining the adaptation capability of reservoirs as the change of maximum and/or minimum of storage corresponding to the change of inflow, the study showed that Gangdong Dam has the worst adaptation capability on the variation of inflow, while Soyanggang Dam has the best capability. This study also constructed an Adaptive Neuro-Fuzzy Inference System (ANFIS) for the more accurate and efficient simulation of the adaptation capability of the Soyanggang Dam. Nine Inflow scenarios were generated using historical data from frequency analysis and synthetic data from two general circulation models with different climate change scenarios. The ANFIS showed significantly different consequences of the release and reservoir storage upon inflow scenarios of Soyanggang Dam, whilst it provides stable reservoir operations despite the variability of rainfall pattern.

Synergistic Effect of Oxygen Pressure and Sonophoresis for Skin Permeability (산소 압력과 초음파를 이용한 피부투과도 증대에 관한 연구)

  • 차민석;이철규;윤영로;이원수
    • Journal of Biomedical Engineering Research
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    • v.23 no.3
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    • pp.189-196
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    • 2002
  • Transdermal drug delivery offers an alternative method to the conventional oral and injection delivery method. Its advantages include its ability to deliver drugs directly into systemic circulation. However, there have been restrictions in its application to deliver drugs because of the skin's barrier function. In this study, we try to combine a Sonophoresis and oxygen Pressure method in order to increase the Permeability of the skin. we used water as the compound and by utilizing the skin impedance method. we measured the hydration Permeability of skin Ultrasound was applied using a sonicator(Solcare-U1000. Solco, Korea) operating at a frequency of 1MHz. oxygen Pressure was applied using a compressor(Oxyjet-Pointer, Nora Bode. Germany) operating at a pressure of 2Bar/cm2. Experiment was performed in vivo for 42 People. We divided the subjects into four smaller groups. A different transdermal drug delivery method was applied for each group on the back of their hand. We measured the skin impedance variations on the hand. during a 20-minute time Period. The control group did not show any significant increase or variation of skin impedance to water. In comparison to the control group(Passive diffusion) the hydration Permeability of the ultrasound group and the oxygen Pressure group was approximately 25 and 30 times higher consecutively. Futhermore, the hydration permeability of the combination of ultrasound and oxygen Pressure group was about 70-fold higher in comparison to the control group(passive diffusion) . The results reveal that a combination of ultrasound and oxygen Pressure will significantly enhance transdermal water transport compared when only one of them is used.