• Title/Summary/Keyword: Light at night

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Microencapsulation of SrAl2O4 : Eu2+,Dy3+ Phosphorescent Phosphor for Enhanced Visibility of Road Lanes (차선의 시인성 향상을 위한 SrAl2O4 : Eu2+,Dy3+ 축광 마이크로 캡슐화에 관한 연구)

  • Park, Jae Il;Jeong, Soo Hwan;Cheong, In Woo
    • Journal of Adhesion and Interface
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    • v.17 no.3
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    • pp.110-116
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    • 2016
  • A decrease in the retro-reflectivity of glass-bead-covered road paint because of a rainwater film significantly reduces the visibility of drivers at night, and has been considered as a critical cause of traffic accidents. For enhanced visibility, the microencapsulation of hydrophobically modified $SrAl_2O_4:Eu^{2+}$,$Dy^{3+}$ phosphorescent phosphor was carried out via suspension polymerization of methyl methacrylate (MMA). The effects of surface modification agent and radical initiator types, loading amount of phosphorescent phosphor, and microcapsule size on the phosphor content ($W_{TGA}$) in the luminous poly(methyl methacrylate) (PMMA) microcapsules were investigated by thermogravimetric analyses (TGA). It was found that the $W_{TGA}$ value was ranged from 7 wt% to 81 wt%, which suggests suspension polymerization is suitable for the preparation of luminous microcapsules with a wide range of phosphor content. At a lower loading amount of phosphor, the $W_{TGA}$ value obviously increased as the microcapsule size decreased; however, the $W_{TGA}$ values with a higher loading amount of phosphor were less affected by the microcapsule size. The luminous microcapsules with the size range of $425{\sim}710{\mu}m$ were collected and tested as a luminous road lanes. It was found that luminance intensities of the microcapsule-coated plates remained higher than $300mcd/m^2$ for up to 100 s in darkness after 20 min of light emitting diode lamp irradiation. The results suggest that the luminous microcapsules can be a candidate for the replacement of glass beads for enhanced visibility of drivers.

Relationship between Circadian Variation in Ictus of Aneurysmal Subarachnoid Hemorrhage and Physical Activity

  • Lee, Jong Min;Jung, Na Young;Kim, Min Soo;Park, Eun Suk;Park, Jun Bum;Sim, Hong Bo;Lyo, In Uk;Kwon, Soon Chan
    • Journal of Korean Neurosurgical Society
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    • v.62 no.5
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    • pp.519-525
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    • 2019
  • Objective : The circadian pattern of the onset time of aneurysmal subarachnoid hemorrhage (aSAH) has been reported by various authors. However, the effect of the degree of physical exertion on the circadian pattern has not been studied in detail. Therefore, we conducted this study to investigate the effect of physical exertion on the circadian pattern of aSAH. Methods : Of the 335 patients presenting with aSAH from January 2012 to December 2017, 234 patients with identifiable onset time and metabolic equivalent (MET) values were enrolled. The onset time of aSAH was divided into 4-hour intervals. The patient's physical exertion was then assessed on a scale between 1 and 8 METs using generally accepted MET values, and categorized into two groups-light exertion (1 to 4 METs) and moderate to heavy exertion (5 to 8 METs)-to determine the effect of the degree of physical exertion on the onset time distribution of aSAH. Multivariate analysis was used to calculate the odds ratio (OR) between the two groups to determine the effect of the degree of physical exertion on each set of time periods. Results : There was a definite bimodal onset pattern that peaked at 08:00-12:00 hours followed by 16:00-20:00 hours (p<0.001). MET values at all time intervals were found to be significantly higher than the night time (00:00-04:00 hours) values (p<0.031). The MET value distribution showed a unimodal pattern that slightly differed from the bimodal distribution of the onset time of aSAH. There were no significant differences in the ORs of each time interval according to the degree of the MET value. Conclusion : This study reaffirmed that aSAH occurs in a bimodal pattern, especially showing the highest prevalence in the morning. Although aSAH could be related to daily activity, there were no significant changes in diurnal variations affected by the degree of physical exertion.

The Study on the Class Difficulty of Elementary Pre-service Teachers' Seasonal Change Unit (초등예비교사의 계절변화 단원에 대한 수업곤란도 연구)

  • Soon-shik Kim
    • Journal of the Korean Society of Earth Science Education
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    • v.16 no.3
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    • pp.340-350
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    • 2023
  • This study analyzed the difficulty level of class on the seasonal change unit for 84 students at a university of education. The conclusions of this study are as follows. First, if we first present the four topics that make up the seasonal changes in elementary science, the subjects that have the greatest difficulty in teaching for prospective elementary school teachers are 'Why do seasonal changes occur?' (Teaching difficulty level 4.05), 'The sun changes depending on the season' What is the difference between the southern altitude and the length of day and night?' (difficulty level of class, 3.12), 'What is the relationship between the altitude of the sun, length of shadow, and temperature during the day?' (difficulty level of class, 2.85), 'How does the temperature change depending on the season?' (class difficulty level 2.80). As a result, in the elementary science season change unit, the class on the four topics 'Why do seasons change?', which is classified as a class topic that requires the concept of spatial perception, showed a higher level of class difficulty than other units. Second, in the seasonal change unit, various factors of class difficulty appeared depending on the class topic. When pre-service elementary school teachers look at the factors that make class difficult when teaching a lesson on seasonal changes in order of frequency, 42 (50%) said 'Experimental instruction for comparing the altitude of solar masculine according to the tilt of the axis of rotation', followed by 'Solar masculine'. 38 people (45%) answered 'Difficulty in explaining mid-high altitude and the length of day and night', 27 people (32%) answered 'Difficulty in explaining the concept of mid-high altitude', and 24 people (32%) answered 'Difficulty in explaining seasonal changes in the sun's position.' 29%), 20 people (24%) said 'Explain the reasonable reason why the height of the light should be adjusted when measuring the solar altitude', and 16 people (19%) said 'It is difficult to explain the reason for the discrepancy between the solar altitude and the maximum temperature'. ), 'difficulties in measuring sand (ground) temperature' were mentioned by 12 people (14%). Third, when analyzing the factors of class difficulty, there were more curriculum factors than teacher factors. In this context, the exploratory activities on 'Why do seasonal changes occur?', the fourth topic of the seasonal change unit in which elementary school pre-service teachers showed the greatest difficulty in teaching, need improvement in terms of the curriculum.

Effects of Water Temperature on Oxygen Consumption in Starry Flounder Platichthys stellatus Reared in Seawater and Freshwater (해수 및 담수사육 강도다리 Platichthys stellatus의 산소소비에 미치는 수온의 영향)

  • Jeong, Min-Hwan;Byun, Soon-Gyu;Lim, Han-Kyu;Min, Byung-Hwa;Kim, Young-Soo;Chang, Young-Jin
    • Korean Journal of Environmental Biology
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    • v.27 no.3
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    • pp.285-291
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    • 2009
  • The effects of water temperature on oxygen consumption (OC) of starry flounder Platichthys stellatus reared in seawater (SW) and freshwater (FW) was performed in closed water-recirculating system containing respiratory chamber. Fish acclimated in separate indoor tanks with SW (nine of fish used, $263.0{\pm}40.4$ g) or FW (nine of fish used, $265.8{\pm}34.8$ g) were sampled. The OC of starry flounder at $15^{\circ}C,\;20^{\circ}C$ and $25^{\circ}C$ were $74.4{\pm}17.0,\;85.9{\pm}15.8,\;98.3{\pm}11.4\;mg\;O_2\;kg^{-1}hr^{-1}$ in SW and $46.7{\pm}12.0,\;63.3{\pm}7.5,\;82.6{\pm}5.3\;mg\;O_2\;kg^{-1}hr^{-1}$ in FW, respectively, showing a linear increase in OC with water temperature. The OC of fish reared in both SW and FW clear diel rhythm, with lower values at daytime and higher values in the night, in accordance with light (09:00~21:00 hr) and dark (21:00~09:00 hr) phases of the diel cycle (12L : 12D) in water temperature at $15^{\circ}C$ and $20^{\circ}C$. However OC of fish reared in both SW and FW showed unclear diel rhythm with light and dark phases of the diel cycle in water temperature at $25^{\circ}C$. Starry flounder reared in FW had higher ventilation rates than those in SW, but SW had higher OC per breath than those in FW.

Growth Characteristics of Lettuce under Different Frequency of Pulse Lighting and RGB Ratio of LEDs (LED의 간헐조명과 RGB 비율에 따른 상추의 품종별 생육 특성)

  • Kim, Sungjin;Bok, Gwonjeong;Lee, Gongin;Park, Jongseok
    • Journal of Bio-Environment Control
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    • v.26 no.2
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    • pp.123-132
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    • 2017
  • This study was aimed to investigate the effect of 1)irradiation with several different ratios using red, green, and blue LEDs and 2)various pulsed light irradiation with 50% duty ratio using red and blue LEDs on the growth and morphogenesis of three lettuce cultivars (Lactuca sativar L. cv. 'Jukchukmeon', 'Lolo Rosa', and 'Grand Rapid') in hydroponics culture system for 4 weeks after transplanting. Seeds were sown in rock-wool plug trays and they were placed in a culture room which was controlled at $23{\pm}1^{\circ}C/18{\pm}1^{\circ}C$ temperature and 50-60/70-85% for day and night, respectively, during cultivation period. Irradiated RGB ratios with LEDs were 6:3:1, 5:2.5:2.5, 3:3:4, 2:2:6, and 1:1:8 with $110{\pm}3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD on the surface of cultivation bed. The frequencies of pulsed lighting was 50, 100, 500, 1,000, 5,000, 10,000, 25,000Hz (20, 10, 0.1, 0.04 ms) with red and blue LEDs and 50% duty ratio. At the RGB ratio of 6:3:1, the average fresh weight of 'Jukchukmeon' was significantly higher than that of other RGB treatments, but no significant difference compared to the fluorescent treatment. The average fresh weight at 1:1:8 RGB ratio in 'Lolo Rosa' was significantly lower than that of other RGB treatments. Leaf number and fresh weight of 'Grand Rapid' were significantly lower in the control and 1:1:8 RGB treatments, compared to the other RGB treatments. As the ratio of blue light increased, leaf length decreased and leaf shape became round in three lettuces. Although there is little change in growth, it could not be found any tendency to affect the growth and morphogenesis of three lettuces caused by increasing or decreasing frequency of pulsed lighting with 50% duty ratio at the $72{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD.

CO2 Exchange in Kwangneung Broadleaf Deciduous Forest in a Hilly Terrain in the Summer of 2002 (2002년 여름철 경사진 광릉 낙엽 활엽수림에서의 이산화탄소 교환)

  • Choi, Tae-jin;Kim, Joon;Lim, Jong-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.2
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    • pp.70-80
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    • 2003
  • We report the first direct measurement of $CO_2$ flux over Kwangneung broadleaf deciduous forest, one of the tower flux sites in KoFlux network. Eddy covariance system was installed on a 30 m tower along with other meteorological instruments from June to August in 2002. Although the study site was non-ideal (with valley-like terrain), turbulence characteristics from limited wind directions (i.e., 90$\pm$45$^{\circ}$) was not significantly different from those obtained at simple, homogeneous terrains with an ideal fetch. Despite very low rate of data retrieval, preliminary results from our analysis are encouraging and worthy of further investigation. Ignoring the role of advection terms, the averaged net ecosystem exchange (NEE) of $CO_2$ ranged from -1.2 to 0.7 mg m$^{-2}$ s$^{-1}$ from June to August in 2002. The effect of weak turbulence on nocturnal NEE was examined in terms of friction velocity (u*) along with the estimation of storage term. The effect of low uf u* NEE was obvious with a threshold value of about 0.2 m s$^{-1}$ . The contribution of storage term to nocturnal NEE was insignificant; suggesting that the $CO_2$ stored within the forest canopy at night was probably removed by the drainage flow along the hilly terrain. This could be also an artifact of uncertainty in calculations of storage term based on a single-level concentration. The hyperbolic light response curves explained >80% of variation in the observed NEE, indicating that $CO_2$ exchange at the site was notably light-dependent. Such a relationship can be used effectively in filling up the missing gaps in NEE data through the season. Finally, a simple scaling analysis based on a linear flow model suggested that advection might play a significant role in NEE evaluation at this site.

The Effect of Structured Information on the Sleep Amount of Patients Undergoing Open Heart Surgery (계획된 간호 정보가 수면량에 미치는 영향에 관한 연구 -개심술 환자를 중심으로-)

  • 이소우
    • Journal of Korean Academy of Nursing
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    • v.12 no.2
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    • pp.1-26
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    • 1982
  • The main purpose of this study was to test the effect of the structured information on the sleep amount of the patients undergoing open heart surgery. This study has specifically addressed to the Following two basic research questions: (1) Would the structed in formation influence in the reduction of sleep disturbance related to anxiety and Physical stress before and after the operation? and (2) that would be the effects of the structured information on the level of preoperative state anxiety, the hormonal change, and the degree of behavioral change in the patients undergoing an open heart surgery? A Quasi-experimental research was designed to answer these questions with one experimental group and one control group. Subjects in both groups were matched as closely as possible to avoid the effect of the differences inherent to the group characteristics, Baseline data were also. collected on both groups for 7 days prior to the experiment and found that subjects in both groups had comparable sleep patterns, trait anxiety, hormonal levels and behavioral level. A structured information as an experimental input was given to the subjects in the experimental group only. Data were collected and compared between the experimental group and the control group on the sleep amount of the consecutive pre and post operative days, on preoperative state anxiety level, and on hormonal and behavioral changes. To test the effectiveness of the structured information, two main hypotheses and three sub-hypotheses were formulated as follows; Main hypothesis 1: Experimental group which received structured information will have more sleep amount than control group without structured information in the night before the open heart surgery. Main hypothesis 2: Experimental group with structured information will have more sleep, amount than control group without structured information during the week following the open heart surgery Sub-hypothesis 1: Experimental group with structured information will be lower in the level of State anxiety than control group without structured information in the night before the open heart surgery. Sub-hypothesis 2 : Experimental group with structured information will have lower hormonal level than control group without stuctured information on the 5th day after the open heart surgery Sub-hypothesis 3: Experimental group with structured information will be lower in the behavioral change level than control group without structured information during the week after the open heart surgery. The research was conducted in a national university hospital in Seoul, Korea. The 53 Subjects who participated in the study were systematically divided into experimental group and control group which was decided by random sampling method. Among 53 subjects, 26 were placed in the experimental group and 27 in the control group. Instruments; (1) Structed information: Structured information as an independent variable was constructed by the researcher on the basis of Roy's adaptation model consisting of physiologic needs, self-concept, role function and interdependence needs as related to the sleep and of operational procedures. (2) Sleep amount measure: Sleep amount as main dependent variable was measured by trained nurses through observation on the basis of the established criteria, such as closed or open eyes, regular or irregular respiration, body movement, posture, responses to the light and question, facial expressions and self report after sleep. (3) State anxiety measure: State Anxiety as a sub-dependent variable was measured by Spi-elberger's STAI Anxiety scale, (4) Hormornal change measure: Hormone as a sub-dependent variable was measured by the cortisol level in plasma. (5) Behavior change measure: Behavior as a sub-dependent variable was measured by the Behavior and Mood Rating Scale by Wyatt. The data were collected over a period of four months, from June to October 1981, after the pretest period of two months. For the analysis of the data and test for the hypotheses, the t-test with mean differences and analysis of covariance was used. The result of the test for instruments show as follows: (1) STAI measurement for trait and state anxiety as analyzed by Cronbachs alpha coefficient analysis for item analysis and reliability showed the reliability level at r= .90 r= .91 respectively. (2) Behavior and Mood Rating Scale measurement was analyzed by means of Principal Component Analysis technique. Seven factors retained were anger, anxiety, hyperactivity, depression, bizarre behavior, suspicious behavior and emotional withdrawal. Cumulative percentage of each factor was 71.3%. The result of the test for hypotheses show as follows; (1) Main hypothesis, was not supported. The experimental group has 282 minutes of sleep as compared to the 255 minutes of sleep by the control group. Thus the sleep amount was higher in experimental group than in control group, however, the difference was not statistically significant at .05 level. (2) Main hypothesis 2 was not supported. The mean sleep amount of the experimental group and control group were 297 minutes and 278 minutes respectively Therefore, the experimental group had more sleep amount as compared to the control group, however, the difference was not statistically significant at .05 level. Thus, the main hypothesis 2 was not supported. (3) Sub-hypothesis 1 was not supported. The mean state anxiety of the experimental group and control group were 42.3, 43.9 in scores. Thus, the experimental group had slightly lower state anxiety level than control group, howe-ver, the difference was not statistically significant at .05 level. (4) Sub-hypothesis 2 was not supported. . The mean hormonal level of the experimental group and control group were 338 ㎍ and 440 ㎍ respectively. Thus, the experimental group showed decreased hormonal level than the control group, however, the difference was not statistically significant at .05 level. (5) Sub-hypothesis 3 was supported. The mean behavioral level of the experimental group and control group were 29.60 and 32.00 respectively in score. Thus, the experimental group showed lower behavioral change level than the control group. The difference was statistically significant at .05 level. In summary, the structured information did not influence the sleep amount, state anxiety or hormonal level of the subjects undergoing an open heart surgery at a statistically significant level, however, it showed a definite trends in their relationships, not least to mention its significant effect shown on behavioral change level. It can further be speculated that a great degree of individual differences in the variables such as sleep amount, state anxiety and fluctuation in hormonal level may partly be responsible for the statistical insensitivity to the experimentation.

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Optical and Physical Properties of Covering Materials for Plastic Greenhouse (플라스틱하우스용 피복재의 광학.물리적 특성)

  • Kwon, Joon Kook;Choi, Young Hah;Park, Dong Kum;Lee, Jae Han;Um, Yeong Cheon;Park, Joong Choon
    • Journal of Bio-Environment Control
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    • v.10 no.3
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    • pp.141-147
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    • 2001
  • To compare to the optical and physical properties of covering materials for plastic greenhouse, EVA(ethylene vinyl acetate, 0.08 mm), polyorefine antifog (0.1 mm), fluoric (0.06 mm), diffused (0.15 mm), polyorefine antidrop (0.15 mm) and PET (polyethylene terephthalate, 0.5 mm) films were used. The small greenhouse (5.4$\times$18.5$\times$2.9 m, W$\times$L$\times$H) investigated during 3 years form 1997 to 1999. After covering materials were used for greenhouse covering during 30 months, UV (300-400 nm) transmittances of diffused film and PET were appeared from 25 to 26%, while those of fluoric film and the other films were 76% and from 63 to 67%. For PAR (photosynthetically active radiation, 400-700 nm), the transmittances of fluoric, antidrop, PET, antifog, EVA, and diffused film were 86.5%, 80.5%, 76.3%, 75.5%, 74.1% and 61.9% respectively. The losses of PAR transmittance of EVA and the antidrop film during period between 7 days and 30 months were higher value 12% and lower value 6% than any other film. Under the canopy of tomato plants, light intensities of the diffused film and the antifog film were 2.5 times and 1.4 times higher than those of PET. Tensile resistances of fluoric film at the break point were the higher than those of antifog film and diffused film. While impact resistance of the antidrop film was the highest value, but the fluoric film was the lowest. Air temperature inside the greenhouse for the day showed to be changed the similar light transmittance of the films. But the increasing order of air temperature for the night was PET, fluoric, antidrop, diffused, antifog and EVA film. Especially, air temperature in the PET was 4$^{\circ}C$ higher than that in the EVA. Solar radiations of the fluoric film, the antidrop film, PET and antifog film in the greenhouse were 32%, 15%, 11% and 4% higher than those of PET. However, those of the diffused film was 7% less than PET.

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Monitoring of Mythimna separata Adults by Using a Remote-sensing Sex Pheromone Trap (원격감지 성페로몬트랩을 이용한 멸강나방(Mythimna separata) 성충 예찰)

  • Jung, Jin Kyo;Seo, Bo Yoon;Cho, Jum Rae;Kim, Yong
    • Korean journal of applied entomology
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    • v.52 no.4
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    • pp.341-348
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    • 2013
  • We desinged and evaluated a remote-sensing sex pheromone trap for real-time monitoring of Mythimna separata (Lepidoptera: Noctuidae), a migratory insect in Korea. The system consisted of a modified cone-trap with a sex pheromone lure, a sensing module based on light interruption, a signal transmission module based on code division multiple access, a main electronic board for system control, a power supply based on a solar collector, a stainless steel-pole supporting the system, and a signal collection and display system based on an internet web page. The ratio (>92%) of the actual number of insects to the signal number in the remote-sensing trap was improved by sensing only within a limited period at night on the basis of the insect's circadian rhythm, control of signal sensitivity on the basis of sensing software programming, 1-h interval for signal transmission, and adjustment of the signal transmission program. The signal occurrence pattern in the remote-sensing trap was conclusively similar (correlation coefficient, >0.98) to the actual pattern of adult occurrence in the trap. The result indicated that the remote-sensing trap based on the attraction of the sex pheromone lure for M. separata has a promising potential for practical use. Occurrence of M. separata adults was observed several times in 2011 and 2012, and the peaks were sharp.

A Research on the Recognition of the Effect of Constitution-Acupuncture Based on the Expert Constitution-Acupuncture Oriental Medical Doctors (팔체질침 전문 한의사의 체질침 효과에 대한 인식조사)

  • Min, Jae-Young;Park, Young-Jae;Park, Jae-Sung;Shin, Yong-Sup;Park, Young-Bae;Lee, Sang-Chul;Kim, Min-Yong
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.11 no.1
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    • pp.105-129
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    • 2007
  • Objectives: The purpose of this research is to obtain basic data about the effects of Constitution-Acupuncture (CA) based on Eight-Constitution Medicine (ECM) by the expert CA Oriental Medical Doctors. Methods: The resources were collected from the internet survey method. 35 samples were collected. The SPSS 13.0 for windows and Answer Tree 3.0 was used for statistical analysis. Results: The results from this research are as follow. 1. The motivation that apply ECM to clinic are 'Because ECM is effective for diagnosis, treatment and prevention against disease' 48.6% and 'Because CA therapy is effective' 25.7%. 2. The advantage that CA therapy compare to the other acupuncture therapy are 'Management and prevention against disease are available by ECM theory to a person who exact constitution is confirmed' 82.9%, 'CA therapy is superior in treatment of hard symptoms to treat by the other acupuncture therapy' 80%, 'Treatment effect is good' 77.1%, 'Needle manipulation of CA is simple comparatively' 57.1%, 'It is definite whether treatment effect is good or not' 54.3% and CA therapy is superior all in diseases of twelve category. 3. When the effects of CA is good, patients expressed much 'Eyesight lightened', 'Took deep sleep at night', 'Fatigue decreased', 'Body is light', 'Feelings became refreshing' as well as 'Symptoms were improved' and also physicians confirmed as those reactions whether treatment is effective. Conclusions: The research suggest that CA is effective therapy in clinic, and so further study is needed for CA therapy.

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