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The Gradient Variation of Thermal Environments on the Park Woodland Edge in Summer - A Study of Hadongsongrim and Hamyangsangrim - (여름철 공원 수림지 가장자리의 온열환경 기울기 변화 - 하동송림과 함양상림을 대상으로 -)

  • Ryu, Nam-Hyong;Lee, Chun-Seok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.6
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    • pp.73-85
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    • 2015
  • This study investigated the extent and magnitude of the woodland edge effects on users' thermal environments according to distance from woodland border. A series of experiments to measure air temperature, relative humidity, wind velocity, MRT and UTCI were conducted over six days between July 31 and August 5, 2015, which corresponded with extremely hot weather, at the south-facing edge of Hadongsongrim(pure Pinus densiflora stands, tree age: $100{\pm}33yr$, tree height: $12.8{\pm}2.7m$, canopy closure: 75%, N $35^{\circ}03^{\prime}34.7^{{\prime}{\prime}}$, E $127^{\circ}44^{\prime}43.3^{{\prime}{\prime}}$, elevation 7~10m) and east-facing edge of Hamyangsangrim (Quercus serrata-Carpinus tschonoskii community, tree age: 102~125yr/58~123yr, tree height: tree layer $18.6{\pm}2.3m/subtree$ layer $5.9{\pm}3.2m/shrub$ layer $0.5{\pm}0.5m$, herbaceous layer coverage ratio 60%, canopy closure: 96%, N $35^{\circ}31^{\prime}28.1^{{\prime}{\prime}}$, E $127^{\circ}43^{\prime}09.8^{{\prime}{\prime}}$, elevation 170~180m) in rural villages of Hadong and Hamyang, Korea. The minus result value of depth means woodland's outside. The depth of edge influence(DEI) on the maximum air temperature, minimum relative humidity and wind speed at maximum air temperature time during the daytime(10:00~17:00) were detected to be $12.7{\pm}4.9$, $15.8{\pm}9.8$ and $23.8{\pm}26.2m$, respectively, in the mature evergreen conifer woodland of Hadongsongrim. These were detected to be $3.7{\pm}2.2$, $4.9{\pm}4.4$ and $2.6{\pm}7.8m$, respectively, in the deciduous broadleaf woodland of Hamyansangrim. The DEI on the maximum 10 minutes average MRT, UTCI from the three-dimensional environment absorbed by the human-biometeorological reference person during the daytime(10:00~17:00) were detected to be $7.1{\pm}1.7$ and $4.3{\pm}4.6m$, respectively, in the relatively sparse woodland of Hadongsongrim. These were detected to be $5.8{\pm}4.9$ and $3.5{\pm}4.1m$, respectively, in the dense and closed woodland of Hadongsongrim. Edge effects on the thermal environments of air temperature, relative humidity, wind speed, MRT and UTCI in the sparse woodland of Hadongsongrim were less pronounced than those recorded in densed and closed woodland of Hamyansangrim. The gradient variation was less steep for maximum 10 minutes average UTCI with at least $4.3{\pm}4.6m$(Hadongsongrim) and $3.5{\pm}4.1m$(Hamyansangrim) being required to stabilize the UTCI at mature woodlands. Therefore it is suggested that the woodlands buffer widths based on the UTCI values should be 3.5~7.6 m(Hamyansangrim) and 4.3~8.9(Hadongsongrim) m on each side of mature woodlands for users' thermal comfort environments. The woodland edge structure should be multi-layered canopies and closed edge for the buffer effect of woodland edge on woodland users' thermal comfort.

Energy expenditure measurement of various physical activity and correlation analysis of body weight and energy expenditure in elementary school children (일부 초등학생의 대표적 신체활동의 에너지소비량 측정 및 에너지소비량과 체중과의 상관성 분석)

  • Kim, Jae-Hee;Son, Hee-Ryoung;Choi, Jung-Sook;Kim, Eun-Kyung
    • Journal of Nutrition and Health
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    • v.48 no.2
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    • pp.180-191
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    • 2015
  • Purpose: There is a lack of data on the energy cost of children's everyday activities, adult values are often used as surrogates. In addition, the influence of body weight on the energy cost of activity when expressed as metabolic equivalents (METs) has not been vigorously explored. Methods: In this study 20 elementary school students 9~12 years of age completed 18 various physical activities while energy expenditure was measured continuously using a portable telemetry gas exchange system ($K_4b^2$, Cosmed, Rome, Italy). Results: The average age was 10.4 years and the average height and weight was 145.1 cm and 43.6 kg, respectively. Oxygen consumption ($VO_2$), energy expenditure and METs at the time of resting of the subjects were 5.41 mL/kg/min, 1.44 kcal/kg/h, and 1.5 METs, respectively. METs values by 18 physical activities were as follows: Homework and reading books (1.6 METs), playing game with a mobile phone or video while sitting (1.6 METs), watching TV while sitting on a comfortable chair (1.7 METs), playing video game or mobile phone game while standing (1.9 METs), sweeping a room with a broom (2.7 METs) and playing a board game (2.8 METs) belong to light intensity physical activities. By contrary, speedy walking and running were 6.6 and 6.7 METs, respectively, which belong to high intensity physical activities over 6.0 METs. When the effect of body weight on physical activity energy expenditure was determined, $R^2$ values increased with 0.116 (playing a game at sitting), 0.176 (climbing up and down stairs), 0.246 (slow walking), and 0.455 (running), which showed that higher activity intensity increased explanation power of body weight on METs value. Conclusion: This study is important for direct evaluation of energy expenditure by physical activities of children, and it could be used directly for revising and complementing the existing activity classification table to fit for children.

THE RELATIONSHIP BETWEEN PARTICLE INJECTION RATE OBSERVED AT GEOSYNCHRONOUS ORBIT AND DST INDEX DURING GEOMAGNETIC STORMS (자기폭풍 기간 중 정지궤도 공간에서의 입자 유입률과 Dst 지수 사이의 상관관계)

  • 문가희;안병호
    • Journal of Astronomy and Space Sciences
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    • v.20 no.2
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    • pp.109-122
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    • 2003
  • To examine the causal relationship between geomagnetic storm and substorm, we investigate the correlation between dispersionless particle injection rate of proton flux observed from geosynchronous satellites, which is known to be a typical indicator of the substorm expansion activity, and Dst index during magnetic storms. We utilize geomagnetic storms occurred during the period of 1996 ~ 2000 and categorize them into three classes in terms of the minimum value of the Dst index ($Dst_{min}$); intense ($-200nT{$\leq$}Dst_{min}{$\leq$}-100nT$), moderate($-100nT{\leq}Dst_{min}{\leq}-50nT$), and small ($-50nT{\leq}Dst_{min}{\leq}-30nT$) -30nT)storms. We use the proton flux of the energy range from 50 keV to 670 keV, the major constituents of the ring current particles, observed from the LANL geosynchronous satellites located within the local time sector from 18:00 MLT to 04:00 MLT. We also examine the flux ratio ($f_{max}/f_{ave}$) to estimate particle energy injection rate into the inner magnetosphere, with $f_{ave}$ and $f_{max}$ being the flux levels during quiet and onset levels, respectively. The total energy injection rate into the inner magnetosphere can not be estimated from particle measurements by one or two satellites. However, the total energy injection rate should be at least proportional to the flux ratio and the injection frequency. Thus we propose a quantity, “total energy injection parameter (TEIP)”, defined by the product of the flux ratio and the injection frequency as an indicator of the injected energy into the inner magnetosphere. To investigate the phase dependence of the substorm contribution to the development of magnetic storm, we examine the correlations during the two intervals, main and recovery phase of storm separately. Several interesting tendencies are noted particularly during the main phase of storm. First, the average particle injection frequency tends to increase with the storm size with the correlation coefficient being 0.83. Second, the flux ratio ($f_{max}/f_{ave}$) tends to be higher during large storms. The correlation coefficient between $Dst_{min}$ and the flux ratio is generally high, for example, 0.74 for the 75~113 keV energy channel. Third, it is also worth mentioning that there is a high correlation between the TEIP and $Dst_{min}$ with the highest coefficient (0.80) being recorded for the energy channel of 75~113 keV, the typical particle energies of the ring current belt. Fourth, the particle injection during the recovery phase tends to make the storms longer. It is particularly the case for intense storms. These characteristics observed during the main phase of the magnetic storm indicate that substorm expansion activity is closely associated with the development of mangetic storm.

Characteristic and Application Under the Sericulture of Subtropical Zones Mulberry Adapted Itself to the Field Cultivation (노지재배(露地栽培)에 적응(適應)한 아열대산(亞熱帶産) 뽕나무의 특성(特性)과 양잠(養蠶)에서의 응용(應用))

  • Seok Young-Seek;Park Sang-Jo;An Sin-Hun;Han Sang-Mi;Yeo Joo-Hong;Han Myung-Sae
    • Journal of Sericultural and Entomological Science
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    • v.47 no.2
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    • pp.68-77
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    • 2005
  • A characteristic of subtropical zones region MK-T2 compares with an gaeryangppong, and the 9-10 schedule the times when a leaf blooms to are fast, and ratio that a branch edge by the colds becomes lean showed 5.7%, and a growth of the new branch which went out delivers 67.2 cm, mulberry loaves of the new branch which went out, and 18.6, a form of a leaf is the 1.10 that length of a leaf grew more a bit than width of a leaf up. Thickness of a leaf is $228.2{\mu}m$, and an area is more similar than gaeryangppong as $225.6cm^2$. in plant taxonomy, the hair whom the style exists short with 0.7 mm, and go to the pistil head inside so as to be rare is distributed, and belong to Dolichostylae Pubescentes. The new branch cutting which executed without remedy processes was independent of a thickness of a case branch, and the form and 100% root was said, and an gaeryangppong compared with the fact that 10% root went out of 15 mm ideal, and was excellent very, and looked, a root went out a root the soil and water, all showed a characteristic to go out at central of a branch bases at 45% ratio. Length was 24.6 mm, and were water rate 78.8%, and mulberry of MK-T2 was carrying together sweetness and acidity to pH 4.7 while, besides, arrival was 19.21 Brix%. A larva period and pupa ratio, cocoon thickness ratio are almost similar to gaeryangppong, or weight of one cocoon, cocoon thickness, 20,002 cocoon quantity shows some results to drop, and be soft of a leaf, and feed value certifications are comparatively top-ranking. As a result of having analyzed amino acid of the 3rd day of 5th silkworm larva which bred to MK-T2, a collation absorbing an gaeryangppong went, and looked, but compared with a collation in case of tests to eat MK-T2, and looked, and the lie collations were not detected a difference at Leu, but MK-T2 tests were detected mutual almost similar amino acid creation. medical efficacy of the 3rd day of 5th silkworm larva ethanol extract which bred to MK-T2 and black results, histologic a case did not appear at HE dyeing about the kidney organization which extracted form the rats which ate a silkworm ethanol extract and dyeing all chemical organization immunity, and one step protein revelation became lower with almost unidentified levels.

The Effectiveness of Fiscal Policies for R&D Investment (R&D 투자 촉진을 위한 재정지원정책의 효과분석)

  • Song, Jong-Guk;Kim, Hyuk-Joon
    • Journal of Technology Innovation
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    • v.17 no.1
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    • pp.1-48
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    • 2009
  • Recently we have found some symptoms that R&D fiscal incentives might not work well what it has intended through the analysis of current statistics of firm's R&D data. Firstly, we found that the growth rate of R&D investment in private sector during the recent decade has been slowdown. The average of growth rate (real value) of R&D investment is 7.1% from 1998 to 2005, while it was 13.9% from 1980 to 1997. Secondly, the relative share of R&D investment of SME has been decreased to 21%('05) from 29%('01), even though the tax credit for SME has been more beneficial than large size firm, Thirdly, The R&D expenditure of large size firms (besides 3 leading firms) has not been increased since late of 1990s. We need to find some evidence whether fiscal incentives are effective in increasing firm's R&D investment. To analyse econometric model we use firm level unbalanced panel data for 4 years (from 2002 to 2005) derived from MOST database compiled from the annual survey, "Report on the Survey of Research and Development in Science and Technology". Also we use fixed effect model (Hausman test results accept fixed effect model with 1% of significant level) and estimate the model for all firms, large firms and SME respectively. We have following results from the analysis of econometric model. For large firm: i ) R&D investment responds elastically (1.20) to sales volume. ii) government R&D subsidy induces R&D investment (0.03) not so effectively. iii) Tax price elasticity is almost unity (-0.99). iv) For large firm tax incentive is more effective than R&D subsidy For SME: i ) Sales volume increase R&D investment of SME (0.043) not so effectively. ii ) government R&D subsidy is crowding out R&D investment of SME not seriously (-0.0079) iii) Tax price elasticity is very inelastic (-0.054) To compare with other studies, Koga(2003) has a similar result of tax price elasticity for Japanese firm (-1.0036), Hall((l992) has a unit tax price elasticity, Bloom et al. (2002) has $-0.354{\sim}-0.124$ in the short run. From the results of our analysis we recommend that government R&D subsidy has to focus on such an areas like basic research and public sector (defense, energy, health etc.) not overlapped private R&D sector. For SME government has to focus on establishing R&D infrastructure. To promote tax incentive policy, we need to strengthen the tax incentive scheme for large size firm's R&D investment. We recommend tax credit for large size film be extended to total volume of R&D investment.

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Statistical Analysis of Operating Efficiency and Failures of a Medical Linear Accelerator for Ten Years (선형가속기의 10년간 가동률과 고장률에 관한 통계분석)

  • Ju Sang Gyu;Huh Seung Jae;Han Youngyih;Seo Jeong Min;Kim Won Kyou;Kim Tae Jong;Shin Eun Hyuk;Park Ju Young;Yeo Inhwan J.;Choi David R.;Ahn Yong Chan;Park Won;Lim Do Hoon
    • Radiation Oncology Journal
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    • v.23 no.3
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    • pp.186-193
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    • 2005
  • Purpose: To improve the management of a medical linear accelerator, the records of operational failures of a Varian CL2l00C over a ten year period were retrospectively analyzed. Materials and Methods: The failures were classified according to the involved functional subunits, with each class rated Into one of three levels depending on the operational conditions. The relationships between the failure rate and working ratio and between the failure rate and outside temperature were investigated. In addition, the average life time of the main part and the operating efficiency over the last 4 years were analyzed. Results: Among the recorded failures (total 587 failures), the most frequent failure was observed in the parts related with the collimation system, including the monitor chamber, which accounted for $20\%$ of all failures. With regard to the operational conditions, 2nd level of failures, which temporally interrupted treatments, were the most frequent. Third level of failures, which interrupted treatment for more than several hours, were mostly caused by the accelerating subunit. The number of failures was increased with number of treatments and operating time. The average life-times of the Klystron and Thyratron became shorter as the working ratio increased, and were 42 and $83\%$ of the expected values, respectively. The operating efficiency was maintained at $95\%$ or higher, but this value slightly decreased. There was no significant correlation between the number of failures and the outside temperature. Conclusion: The maintenance of detailed equipment problems and failures records over a long period of time can provide good knowledge of equipment function as well as the capability of predicting future failure. Wore rigorous equipment maintenance Is required for old medical linear accelerators for the advanced avoidance of serious failure and to improve the qualify of patient treatment.

Study of The Area of Nursing Need by the Family Developmental Stage (가족발달단계에 따른 간호요구영역에 관한 연구)

  • 최부옥
    • Journal of Korean Academy of Nursing
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    • v.7 no.2
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    • pp.43-59
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    • 1977
  • The Community Health Service considers the family as a service unit and places the emphasis of its service on the health problems and the nursing needs of the family rather than the individual. From the conceptual point of view that tile community health service is both health maintenance and health promotion of the family, the community health nurse should have a knowledge of the growth and development of the family and be responsible for the comprehensive support of normal family development. The community health nurse often is in a position to make a real contribution to normal family development. In order to investigate the relationship between the areas of nursing need and family development, the following objectives were established 1. To discover the general characteristics of the study population by the stage of family development. 2. To discover specific nursing needs in relation to the family developmental stage, and to determine the intensity of the nursing needs and the ability of the family to cope with these needs. 3. To discover overall family health nursing problems in relation to the family developmental stage and determine the intensity of the nursing need and the problem solving ability of family. Definitions : The family developmental stages as classified by Dually were used stage 1. Married couples(without children) stage 2. Childbearing Families (oldest child birth to 30 months of age) stage 3. Families with preschool children (oldest child 2½-to 6 years) stage 4. Families with schoolchildren (oldest child 6 to 13 years). stage 5. Families with teenagers (oldest child 13 to 20 years) stage 6. Families as launching centers (first child gone to last child′s leaving home). stage 7. Middle- aged parents (empty nest to retirement) stage 8. Aging family member (retirement to death of both spouses) The areas of nursing need were defined as those used in the study, "A Comprehensive Study about Health and Nursing Need and a Social Diagram of the Community", by tile Nursing research Institute and Center for population. and Family Planning, July 1974. The study population defiled and selected were 260 nuclear families ill two myron of Kang Hwa Island. Percent, mean value and F- test were utilized in tile statistical analysis of the study result. Findings : 1. General characteristics of the study population by tile family developmental stage ; 1)The study population was distributed by the family developmental stage as follows : stage 1 : 3 families stage 2 : 13 families stage 3 : 24 families stage 4 : 41 families stage 5 : 50 families stage 6 : 106 families stage 7 : 13 families stage 8 : 10 families 2) Most families had 4 or 5 members except for those in stage, 1, 7, and 8. 3) The parents′ present age was older in the higher developmental stage and their age at marriage was also younger in the higher developmental stages. 4) The educational level of parents was primarily less than elementary school irrespective of the developmental stage. 5) More than half of parents′ occupations were listed as laborers irrespective of the developmental stage, 6) More than half of the parents were atheists irrespective of the developmental stage. 7) The higher the developmental stage(from stage 2 to stage 6 ), the wider the distribution of children′s ages. 8) More than half of the families were of middle or lower socio-economic level. 2. Problems in specific areas of nursing need by family developmental stage, the intensity of nursing need and the problem solving ability of the family : 1) As a whole, many problems, irrespective of the developmental stage, occurred in tile areas of Housing and Sanitation, Eating Patterns, Housekeeping, Preventive Measures and Dental care. Problems occurring ill particular stages included the following ; stage 1 : Prevention of Accident stage 2 : Preventive Vaccination, Family Planning. stage 3 : Preventive Vaccination, Maternal Health, Family Planning, Health of Infant and Preschooler. stage 4, 5 : Preventive Vaccination, Family Planning, Health of School Children. stage 6 : Preventive Vaccination, Health of School Children. 2) The intensity of the nursing need in the area of Acute and Chronic Diseases was generally of moderate degree or above irrespective of the developmental stages except for stage 1. Other areas of need listed as moderate or above were found in the following stages: stage 1 : Maternal Health stage 3 . Horsing and Sanitation, Prevention of Accident. stage 4 . Housing and Sanitation. stage 5 : Housing and Sanitation, Diagnostic and Medical Care. stage 6 : Diagnostic and Medical care stage 7 : Diagnostic and Medical Care, Housekeeping. stage 8 : Housing and Sanitation, Prevention of Accident, Diagnostic and Medical Care, Dental Care, Eating Patterns, Housekeeping. 3) Areas of need with moderate problem solving ability or less were as follows : stage 1 : Diagnostic and Medical Care, Maternal Health. stage 2 : Prevention of Accident, Acute and Chronic Disease, Dental Care. stage 3 : Housing and Sanitation, Acute and Chronic Disease, Diagnostic and Medical Care, Preventive Measure, Dental Care, Maternal Health, Health of Infant and preschooler, Eating Patterns. stage 4 : Housing and Sanitation, Prevention of Accident, Diagnostic and Medical Care, Preventive Measure, Dental Care, Maternal Health, Health of New Born, Health of Infant and Preschooler, Health of school Children, Eating Patterns, Housekeeping. stage 5 . Housing and Sanitation, Prevention of Accident, Acute and Chronic Disease, Diagnostic and Medical Care, Preventive Measure, Dental Care, Preventive Vaccination, Maternal Health, Eating Patterns. stage 7, 8 : Housing and Sanitation, Prevention of Accident, Acute and Chronic Disease, Diagnostic and Medical Care, Preventive Measures, Dental Care, Preventive Vaccination, Eating Patterns , Housekeeping. Problem occurrence, the degree of nursing need and the degree of problem solving ability 1 nursing need areas for the family as a whole were as follows : 1) The higher the stages(except stage 1 ), the lower the rate of problem occurrence. 2) The higher the stage becomes, the lower the intensity of the nursing need becomes. 3) The higher the stages (except stages 7 and 8), the higher. the problem solving ability. Conclusions ; 1) When the nursing care plan for the family is drawn up, depending upon the stage of family development, higher priority should be give to nursing need areas ① at which problems were shown to occur ② where the nursing need is shown to be above moderate degree and ③ where the problem solving ability was shown to be of moderate degree. 2) The priority of the nursing service should be Placed ① not on those families in the high developmental stage but on those families in the low developmental stage ② and on those areas of need shown in stages 7 and 8 where the degree nursing need was high and the ability to cope low.

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EVALUATION OF SERUM LEVELS OF SYSTEMIC STATUS IN ORAL AND MAXILLOFACIAL SURGERY PATIENTS (구강악안면 수술을 받은 환자들에서의 전신영양평가)

  • Kim, Uk-Kyu;Kim, Yong-Deok;Byun, June-Ho;Shin, Sang-Hun;Chung, In-Kyo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.5
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    • pp.301-314
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    • 2003
  • The purposes of this retrospective study were to assess the change of serum parameters in oral and maxillofacial surgery patients after operation and to determine what laboratory parameters on treatment periods were associated with the recovery of systemic condition. For purposes of assessing systemic nutritional status, several serum parameters were chosen. The sample patients were randomsubjects extracted from three category patient groups- oral cancer, odontogenic abscess, facial bone fracture based on treated patients at department of oral and maxillofacial surgery in Pusan National University Hospital from September 1, 1998, to September 1, 2002. Each groups were consisted with 10 patients. Each patient chart was examined and blood sample parameters were reviewed with clinical signs, symptoms and vital sign at preoperative day, postoperative 1 day, postoperative 1 week. Several parameters were analyzed statistically for extraction of mean values and differences between the periods groups. The findings of serum parameters of cancer, abscess and fracture groups were as follows: 1. In cancer patients, Hb, MCV, albumin, cholesterol, LDH, AST, ALT, neutrophil, platelet, leukocyte, Na, K, Cl, BUN, creatinine were analyzed. Values of Hb, albumin, AST, neutrophil, leukocyte, Cl showed significantly differences according to periods. 2. In abscess patients, CRP, ESR, leukocyte, body temperature, neutrophil were analyzed. Values of CRP, leukocyte, body temperature, neutrophil showed significanlty differences according to periods. 3. In fracture patients, same parameters with cancer patient's were chosen. Values of platelet, Cl only showed significantly differences according to periods. 4. In cancer patients, data regarding correlation was analyzed statistically as Pearson's value. A positive correlation was found between Hb and albumin, K, Na(P<0.05). A positive correlation was also found between neutrophil and leukocyte(P<0.05). Positive correlations were found between cholesterol and ALT, LDH and platelet, creatinine both, Platelet and BUN, Na and K(P<0.01). 5. In abscess patients, Peason's correlation values were analyzed on parameters. A positive correlation was found only between CRP and neutrophil(P<0.05). 6. In fracture patients, The correlations of parameters also were statistically analyzed. Positive correlations were found between MCV and K, albumin and LDH, AST and three parameters of creatinine, Na, Cl, K and neutrophil, neutrophil and three parameters of leukocyte, BUN, K(P<0.05). Positive correlations were found between LDH and AST, ALT and AST, creatinine both(P<0.01). This retrospective clinical study showed the CRP levels only on abscess patients may be useful in determination of clinical infected status, but the levels of other parameters on cancer, fracture patients did not showed significant values as diagnostic aids for clinical status.

Study on the Tractive Characteristics of the Seed Furrow Opener for No-till Planter (무경운(無耕耘) 파종기용(播種機用) 구체기(溝切器)의 견인특성(牽引特性)에 관(關)한 연구(硏究))

  • La, Woo-Jung
    • Korean Journal of Agricultural Science
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    • v.5 no.2
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    • pp.149-157
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    • 1978
  • This study was carried out to obtain basic data for the type selection of furrow openers for the no-tillage soybean planter trailed by the two-wheel tractor from the standpoint of minimum draft and good performance of furrowing. For this study, two models of furrow opener, hoe and disc type, were tested on the artificial soil stuffed in the moving soil bin. The results obtained were as follows. In the case of disc furrow opener, the drafts were measured according to various diameters of discs under the condition of disc angle $8^{\circ}$ and $16^{\circ}$, working depth 3cm and 6cm, working speed 2.75cm/sec. Minimum draft appeared when the diameter of disc was about 28cm and the drafts increased as the diameter of discs became larger or smaller than this diameter. Specific draft showed almost same tendencies as above but showed the minimum when the diameter was about 30cm. For the purpose of controlling the seeding depth, the relationships between draft and working depths, 3cm and 6cm, were tested. The variations of draft concerning the various working depths showed linear changes and were affected in higher degree by depths than other factors. There were general tendencies at both working depths, 3cm and 6cm, that total draft showed the minimum with the disc diameter of about 28cm and specific draft showed it with the disc diameter of about 30cm regardless of disc angle and working speed. For the purpose of controlling the working width and speed, the relationships among drafts, disc angle and working speed were investigated and there were general tendencies that the draft increased as the angle and speed were increased and the draft was affected more by speed than by angle. To compare the hoe-type with disc-type opener, the specific drafts of hoe openers were compared with those of disc opener of $16^{\circ}$ angle and 30cm diameter. The specific draft of disc-type opener with the diameter of 30cm was $0.35{\sim}0.5kg/cm^2$, while $0.71{\sim}1.02kg/cm^2$ in the case of hoe type with the lift angle of $20^{\circ}$ which is 2 times as much as that of disc type in average value. And the furrows opened by disc openers were cleaner than those opened by hoe openers.

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Assessment for the Utility of Treatment Plan QA System according to Dosimetric Leaf Gap in Multileaf Collimator (다엽콜리메이터의 선량학적엽간격에 따른 치료계획 정도관리시스템의 효용성 평가)

  • Lee, Soon Sung;Choi, Sang Hyoun;Min, Chul Kee;Kim, Woo Chul;Ji, Young Hoon;Park, Seungwoo;Jung, Haijo;Kim, Mi-Sook;Yoo, Hyung Jun;Kim, Kum Bae
    • Progress in Medical Physics
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    • v.26 no.3
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    • pp.168-177
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    • 2015
  • For evaluating the treatment planning accurately, the quality assurance for treatment planning is recommended when patients were treated with IMRT which is complex and delicate. To realize this purpose, treatment plan quality assurance software can be used to verify the delivered dose accurately before and after of treatment. The purpose of this study is to evaluate the accuracy of treatment plan quality assurance software for each IMRT plan according to MLC DLG (dosimetric leaf gap). Novalis Tx with a built-in HD120 MLC was used in this study to acquire the MLC dynalog file be imported in MobiusFx. To establish IMRT plan, Eclipse RTP system was used and target and organ structures (multi-target, mock prostate, mock head/neck, C-shape case) were contoured in I'mRT phantom. To verify the difference of dose distribution according to DLG, MLC dynalog files were imported to MobiusFx software and changed the DLG (0.5, 0.7, 1.0, 1.3, 1.6 mm) values in MobiusFx. For evaluation dose, dose distribution was evaluated by using 3D gamma index for the gamma criteria 3% and distance to agreement 3 mm, and the point dose was acquired by using the CC13 ionization chamber in isocenter of I'mRT phantom. In the result for point dose, the mock head/neck and multi-target had difference about 4% and 3% in DLG 0.5 and 0.7 mm respectively, and the other DLGs had difference less than 3%. The gamma index passing-rate of mock head/neck were below 81% for PTV and cord, and multi-target were below 30% for center and superior target in DLGs 0.5, 0.7 mm, however, inferior target of multi-target case and parotid of mock head/neck case had 100.0% passing rate in all DLGs. The point dose of mock prostate showed difference below 3.0% in all DLGs, however, the passing rate of PTV were below 95% in 0.5, 0.7 mm DLGs, and the other DLGs were above 98%. The rectum and bladder had 100.0% passing rate in all DLGs. As the difference of point dose in C-shape were 3~9% except for 1.3 mm DLG, the passing rate of PTV in 1.0 1.3 mm were 96.7, 93.0% respectively. However, passing rate of the other DLGs were below 86% and core was 100.0% passing rate in all DLGs. In this study, we verified that the accuracy of treatment planning QA system can be affected by DLG values. For precise quality assurance for treatment technique using the MLC motion like IMRT and VMAT, we should use appropriate DLG value in linear accelerator and RTP system.