• Title/Summary/Keyword: comparative studies

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Determination of Grades and Design Strengths of Machine Graded Lumber in Korea (국내 기계등급구조재의 등급구분체계 및 기준설계값 결정방법 연구)

  • Hong, Jung-Pyo;Lee, Jun-Jae;Park, Moon-Jae;Yeo, Hwanmyeong;Pang, Sung-Jun;Kim, Chul-Ki;Oh, Jung-Kwon
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.4
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    • pp.446-455
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    • 2015
  • Based on comparative studies on standards and grading procedures of machine graded lumber in Korea and other countries, this study proposed a procedure of determining the grade classification and design strengths of domestic machine graded lumber. Differences between machine stress rated lumber and E-rated laminations were detailed in order to clarify the need for the procedure improvement. To this improvement the use of average MOE requirement for grading was introduced instead of the fixed minimum MOE requirement which is currently used in the Korean standards. It was found that the fixed minimum MOE requirement method was easier for an inspector to grade but, less efficient as a strength predictor than the average MOE requirement method. The advantage of average MOE requirement method is statistically MOR-MOE regression-based MOR prediction and highly efficient in quality control though it requires a computer-aided operation system in an initial setup. A major weakness of the current Korean grading system was found that different strength characteristics depending on wood species were not reflected on the grade classification and the tabulated allowable design stress. The proposed procedures were developed taking advantages of respective merits of both methods and based on MOR-MOE regression analysis. Through this procedure, the grades of machine stress rated lumber should be revised to become interchangeable with E-rated lamination, which would be beneficial to the cost competitiveness of domestic machine graded lumber and glued laminated timber industry.

Effect of Ischemic Preconditioning on Myocardial Protection - A Comparative Study between Normothermic and Moderate Hypothermic Ischemic Hearts Induced by Cardioplegia in Rats - (허혈 전처치가 심근보호에 미치는 영향 - 적출 쥐 심장에서 상온에서의 심근허혈과 중등도 저체온하에서 심근정지액 사용 시의 비교 연구 -)

  • 조성준;황재준;김학제
    • Journal of Chest Surgery
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    • v.36 no.5
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    • pp.242-254
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    • 2003
  • Background: Most of the studies conducted have investigated the beneficial effects of ischemic preconditioning on normothermic myocardial ischemia. However, the effect of preconditioning could be attenuated through the use of multidose cold cardioplegia as practiced in contemporary clinical heart surgical procedures. The purpose of this study was to investigate whether preconditioning improves postischemic cardiac function in a model of $25^{\circ}C$ moderate hypothermic ischemic heart induced by cold cardioplegia in isolated rat hearts. Material and Method: The isolated Sprague-Dawley rat hearts were randomly assigned to four groups All hearts were perfused at 37$^{\circ}C$ for 20 minutes with Krebs-Henseleit solution before the baseline hemodynamic data were obtained, Group 1 consisted of preconditioned hearts that received 3 minutes of global ischemic preconditioning at 37$^{\circ}C$, followed by 5 minutes of reperfusion before 120 minutes of cardioplegic arrest (n=6). Cold (4$^{\circ}C$) St. Thomas Hospital cardioplegia solution was infused to induce cardioplegic arrest. Maintaining the heart at $25^{\circ}C$, infusion of the cardioplegia solution was repeated every 20 minutes throughout the 120 minutes of ischemic period. Group 2 consisted of control hearts that underwent no manipulations between the periods of equilibrium and 120 minutes of cardioplegic arrest (n=6). After 2 hours of cardioplegic arrest, Krebs solution was infused and hemodynamic data were obtained for 30 minuts (group 1, 2: cold cardioplegia group). Group 3 received two episodes of ischemic preconditioning before 30 min of 37$^{\circ}C$ normothermic ischemia and 30 minutes of reperfusion (n=6) Group 4 soloed as ischemic controls for group 3 (group 3, 4: warm ischemia group). Result: Preconditioning did not influence parameters such as left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), rate-pressure product (RPP) and left ventricular dp/dt (LV dp/dt) in the cold cardioplegia group. (p=NS) However, preconditioning before warm ischemia attenuated the ischemia induced cardiac dysfunction, Improving the LVSP, LVEDP, RPP, and LV dp/dt. Less leakage of CPK and LDH were observed in the ischemic preconditioning group compared to the control group (p<0.05). Conclusion: Ischemic preconditioning improved postischemic cardiac function after warm ischemia, but did not protect cold cardioplegic hearts.

Analyzing the characteristics of mathematics achievement in Korea through linking NAEA and PISA (국가수준 학업성취도 평가와 국제 학업성취도 평가의 연계를 통한 우리나라 학생들의 수학 성취 특성 분석)

  • Rim, Hae-Mee;Kim, Su-Jin;Kim, Kyung-Hee
    • Journal of Educational Research in Mathematics
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    • v.22 no.1
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    • pp.1-22
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    • 2012
  • The purpose of this study is to understand Korea students' characteristics as well as to give important information of improving our education using comparative analysis of framework, test booklets, test results between PISA 2009 and NAEA 2009. PISA 2009 was administered on May of 2009 and NAEA was administered on October of same year. The summary of the results of comparing two assessment is as follows First, cut score of NAEA Advance level is bigger than the cut score of level 5, which is considered as high achievement level. The cut score of Basic level of NAEA is also higher than the level 2 of PISA, which is considered as basic achievement level. This phenomenon can show that NAEA achievement level is set little bit higher than the achievement level of PISA in mathematics domain. Second, the percentage of female students on higher level was higher than that of male students. In suburban area, the percentage of high level was small and the percentage of low level was big. Third, students of Advanced level are distributed concentrating in PISA levels 4~6, Proficient achievement level concentrating in PISA levels 3~5, Basic achievement level concentrating in PISA levels 2~4, and below basic achievement levels concentrating in below level 1 and level 3 of PISA. Fourth, the correlation between NAEA 2009 and PISA 2009 achievement scores are significantly positive. However, the correlation of subscales were low. Fifth, analysis of non-equivalent group, 11 items located in 'change and relationship', 'uncertainty', 'connection cluster' domains found to be significantly different. The percent correct showed very big difference. The analysis results presents the implication of mathematics curriculum, teaching and learning methods as well as National Assessment of Educational Achievement.

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Comparative Studies on the Enzymatic Properties of Trypsins from Cat-shark and Mackerel -1. Purifications and Reaction Conditions of the Trypsins- (복상어와 고등어의 Trypsin에 관한 비교 효소학적 연구 -1. Trypsin의 정제와 반응조건-)

  • PYEUN Jae-Hyeung;CHO Deuk-Moon;HEU Min-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.24 no.5
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    • pp.273-288
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    • 1991
  • To elucidate the physiological and biochemical differences between chondrichthyes and osteichthyes, the properties of the specific digestive enzymes in cat-shark, Cephaloscyllium umbratile, and mackerel, Scomber japonicus, were studied. Homogenous trypsin proved through the disc-electrophoresis, SDS-PAG electrophoresis and gel filtration was obtained from the pancreas of cat-shark by $50-70\%$ saturated ammonium sulphate fractionation, DEAE-Sephadex A-50 column chromatography, benzamidine-Sepharose 6B affinity chromatography and Sephadex G-75-120 gel filtration. Two types of trypsins were also obtained from the pyloric caeca of mackerel by $30-70\%$ saturated ammonium sulphate fractionation and the slightly modified procedure from the method adopted in the purification of cat-shark trypsin. The two trypsins, designated trypsin A and B, were proved their homogeneity by disc- and SDS-PAG electrophoresis and gel filtration. The molecular weights of the trypsins were estimated to be 31,700 for cat-shark trypsin, 30,000 for mackerel trypsin A and 29,000 for mackerel trypsin B by SDS-PAG electrophoresis, but those were estimated to be 21,500 for cat-shark trypsin, 23,700 for mackerel trypsin A and 21,500 for mackerel trypsin B by gel filtration. The trypsins exhibited their optimum conditions at pH 9.0 and on temperature ranged from $45^{\circ}C\;to\;50^{\circ}C$ for cat-shark, and at pH 8.0 and a temperature of $50^{\circ}C$ for mackerel trypsin A and B, respectively. The cat-shark trypsin was stable at pH 10.0 and the temperature below $10^{\circ}C$, whereas the mackerel trypsin A and B, were stable in the range over pH 7.0 to pH 9.0 below $10^{\circ}C$ and at pH 8.0 below $35^{\circ}C$, respectively. The mackerel trypsins were severely inhibited by some heavy metal ions such as $Ag^{2+},\;Cu^{2+}\;and\;Hg^{2+}$ compared to cat-shark trypsin. All of the enzymes were also inhibited by antipain, leupeptin, TLCK(tosyllysine chloromethyl ketone) and SBTI(soybean trypsin inhibitor) remarkably. The inhibitory effects of PMSF(phenylmethane sulphonylfluoride), DFP(diisopropyl fluorophosphate) and benzamidine were indicated that these enzymes belong to serine-proteases.

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The Comparative Studies on the Distribution and Species Composition of Forest Community in Korea and Japan around the East Sea (한국과 일본의 동해안 지역에 분포하는 산림군락의 종조성과 분포에 관한 비교 연구)

  • Yun, Jong-Hak;Hukusima, Tukasa;Kim, Moon-Hong;Yoshikawa, Masato
    • Korean Journal of Environment and Ecology
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    • v.25 no.3
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    • pp.327-357
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    • 2011
  • This study compared the species composition and distribution of the forest communities between Korea and Japan using vegetation releve database. The study included the eastern and southern Korean Peninsula, Is. Jeju, Is. Ulreung, northern Kyushu, central part of Japan and Is. Tsushima and divided in fourteen region with major mountain as the center. Seventy-nine forest communities were classified by tabular comparison with the total of 1844 releves. In the composition table, fifty-four groups of plant species were listed. Some grew in one area exclusively, while others were present in multiple locations. This study showed the similarity and heterogeneity of species composition among study areas. We grouped fourteen types showing similar physiognomy for forest communities. The physiognomical features of the vertical vegetation zones in the study area were similar, however, dominant species and species composition were different between the regions. In the lowland zone, Castanopsis-Type dominated by Castanopsis cuspidata var. sieboldii or Castanopsis cuspidata were distributed in the study area except for northern part of the Korean Peninsula and Is. Ulreung. Additionally, Persea thunbergii-Type was distributed widely in the lowest part of the study area, however, it showed the simplification of the species composition in the Korean Peninsula and Is. Ulreung. In the hilly zone, evergreen forest composed by Abies firma-Type distributed in northern Kyushuand Is. Tsushima, but it was absent in the other study region. The difference in forest community was conspicuous, especially in the montane zone. Deciduous broadleaved forests composed Quercus(D)-Type and Fagus-Type widely distributed in the montane of study area. However, forest community dominated by Quercus mongolica and Fagus multinervis flourished in Korea. On the otherhand, forest community dominated by Quercus mongolica var. grosseserrata, Fagus crenata and F. japonica distributed in Japan. In the sub-alpine zone, evergreen coniferous forest composed Abies-Quercus(D)-Type, Abies koreana-Type, and Pinus pumila-Type were distributed in the Korean Peninsula and Is. Jeju. Forests composed Taxus cuspidata var. nana-Type, Abies mariesii-Type, and Pinus pumila-Type distributed in the central part of Japan. As a result of DCA ordination, evergreen broadleaved forests of the whole study area showed the lower scores along the first axis, while deciduous and coniferous forests showed the higher scores. The forest types of western part of Japan were located the higer scores, forest types of the Korean Peninsula were located the lower scores, and forest types of Is. Jeju located in the middle. Warmth index (WI) and Annual range of temperature in climate factor were highly correlated on the first axis. The first axis reflected the gradient from oceanic climatic to continental one. The higher the altitude and further geographically, the lower the similarity among communities and the peculiarity of community appeared stronger. The historical background reflecting local flora has strongly influenced on development of community.

A Study on Awareness of Job Characteristics and Job Satisfaction of Landscape Architect Public Officials in Korea (조경직 공무원의 직무특성 및 직무만족 인식에 관한 연구)

  • Park, Tae-Seok;Kim, Shin-Won
    • Journal of the Korean Institute of Landscape Architecture
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    • v.44 no.6
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    • pp.148-161
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    • 2016
  • In the case of the government, which plays a pivotal role in the landscape architecture system, the management of positions in landscape architectural organizations is lacking. At the local government level, while public officials for managing landscape architecture are being hired, there are problems and vulnerabilities in both management and system operations as such public officials recruited for positions in landscape architectural services operate under the forestry service. Accordingly, this study analyzed the Korean administrative system of public officials in the landscape architectural service and their satisfaction with the organizational culture and behavior. The aim was to provide practical data for improving the job satisfaction of public officials in landscape architectural service and enhance the status of landscape architecture. First, a survey was conducted regarding current organizational culture/behavior and job adequacy, and differences when compared to different job series with regards to the public officials in the landscape architectural service. The results indicated that job satisfaction of those in landscape architectural service was generally high, but they showed strong centralization, i.e., orders from superiors and limitations on autonomy. Second, an analysis was conducted to improve the organizational culture/behavior and job satisfaction of public officials in the landscape architectural service, and a comparative analysis was conducted on the differences between the analysis result and preceding studies by the Ministry of Government Administration and Home Affairs(2006). The results indicated that organizational commitment/satisfaction of public officials in the landscape architectural service was relatively low among those who had a great amount of work experience related to forestry. Therefore, it was shown that it is necessary to ensure expertise in landscape architecture. Third, a comprehensive analysis was conducted regarding the influences on "working environment", "legal system" and "job allocation" in regard to public officials in land architectural service. The results indicated that satisfaction in the value system was high when given significance to the job as public officials in land architectural. However, their satisfaction in the land architectural system was low due to the lack of independence in their positions, the vulnerable legal system of land architectural service and low employment rates. Fourth, current public officials in landscape architectural service process tasks such as forestry, architecture, city planning and administration that are not related to their area of expertise. Therefore, an analysis was conducted on whether there is a difference in the job satisfaction of public officials in landscape architectural service according to statistical variables. It was identified that "legal system", "job satisfaction" and "organizational commitment" with regard to public officials in landscape architectural service can be improved through ensuring their expertise. This study suggests the following tasks to further inquire into landscape architecture in general. First, establish an identity of work allocation for public officials in the landscape architectural service, and second, establish an organizational constitution according to the positions in landscape architectural service. Accordingly, it is necessary for interested parties of landscape architecture to devise practical strategies so that such tasks can be converged administratively and reflected in policies.

A comparative Study of Changing Pattern of Cause of Death Analysis of Korean, Korean in Japan and Japanese (재일한국인의 생활문화의 이질화와 적응과정에 관한 보건학적 연구(제 1보 한국, 재일한국인, 일본의 사인구조분석)

  • 김정근;장창곡;임달오;김무채;이주열
    • Korea journal of population studies
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    • v.15 no.2
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    • pp.15-59
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    • 1992
  • After world war II Japanese life expectancy has been improved remarkably, and reached the highest level in the world around late 1970's. The life expectancy of Korean has also shown tremendous improvement in recent years with about 20 year's gap from the Japanese. The reason of rapid improvement of life expectancy can be explained by changes in the structure of cause of death due to health system, living standard, social welfare, health behavior of individuals and so on. Korean in Japan is placed under different situations from both Korean in Korea and Japanese in these regards, and expected to show different picture of cause of death pattern. The objective of this study is the comparision of changing patterns of cause of death of three population groups, Korean in Japan, Korean in Korea and Japanese, and to investigate the reasons which effect to the structural difference of mortality cause with special emphasis on health ecological aspects. One of the major limitations of the Korean causes of death statistics is the under-registration which ranges about 10% of the total events, and inaccuracy of the exact cause of death. Some 20% of registered deaths were unable to classify by ICD. However, it is concluded that the Korean data are evaluated as sufficient to stand for over-viewing of trends of cause of death pattern. The evaluation is done by comparing data from registration and field survey over the same population sample. Population data of Korean in Japan differ between two sources of data; census and foreigner's registration. Correction is done by life table method under the assumption that age-specific mortality pattern would accord with that of the Japanese. The crude death rate was lowest among Korean in Japan, 5.7 deaths per 1,000 population in 1965. The crude death rates of Korean in Japan and Japanese are increasing recently influenced by age structure while Korean in Korea still shows decreasing tendency. The adjusted death rate is lowest among Japanese, followed by Korean in Japan, and Korean in Korea. The leading causes of death of Korean in Korea until 1960's was infectious diseases including pneumonia and tuberculosis. The causes of death structure changed gradually to accidents, neoplasm, hypertensive disease, cerebro-vascular disease in order. The main difference in cause of death between Korean and Japanese if high rate of liver diseases and diabetes for both Korean in Japan and Korea. A special feature of cause of death among Korean in Korea is remakably high rate of hypertensive disease, which is assumed to be caused by physicians tendency in choosing diagnostic categories. The low ischemic heart disease and high vasculo-cerebral disease are the distinctive characteristic of the three population groups compared to western countries. Specific causes of death were selected for detailed sex, age and ethnic group comparisons based on their high death rates. Cancer is the cause of death which showed most dramatical increase in all three population groups. In Korea 20.1% of all death were caused by cancer in 1990 compared with 10.5% in 1981. Cancer of the liver is the leading cause of cancer death among Korean in Japan for both sexes, followed by cancer of the lung and cancer of the stomach, while that of Korean in Korea is cancer of the stomach, followed by cancer of the liver and cancer of the lung for male. Causes of infant mortality were examined among the three population groups since 1980 on yearly bases. For both Japanese and Korean in Japan, leading cause of death ranks as conditions originating in the perinatal period, congenital anomalies, accidents and other violent causes. Trends since 1980 for these two population groups in the leading cause of infant mortality showed no changes. On the contrary, significant changes in leading cause of death structure in Korea were observed : the ranking of leading cause of death in 1981 were congenital asnomalies, pneumonia bronchitis, infectious disease, heart disease, conditions originating in the perinatal period, accident and other violent causes ; in 1990 the ranking shifted to congenital anomalies, accident, pneumonia bronchities, conditions originating in the perinatal period, infectious disease. The mortality rate by congenital anomalies in Korea continuously grew than any other causes. Larger increase ocurred during the 1990's

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Studies on the Comparative Analysis of Immunofunction of Agaricus blazei Murill Cultivated with Fermented Media Containing Pueraria thunbergiana (칡혼합 발효배지로 생산된 신령버섯의 면역기능성 비교 분석에 관한 연구)

  • 김주남;서정식;박동철
    • Food Science and Preservation
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    • v.9 no.1
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    • pp.114-119
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    • 2002
  • This research was performed to investigate the immnomodulative effects of ploysaccharides extracted from the fruiting body of Agarcus blazei cultivated with the media which are fermented with sugar cane bagasse containing Pueraria thunbergiana in open-air storage. In MTT test, methanol extracts from the fruiting body of A. blazei cultivated with P. thunbergiana media showed in colon carcinoma line(HT29) by 1.5∼3.5 fold and human heptoma cell line (HepG2) by 1.3 ∼2.4 fold antitumor activites compared to two types media (rice straw plus sugar cane bagasse, rice straw only) often used in the fauns. To clarify the antimutagenic principles, three extracts, Ab-l, Ab-2 and Ab-3, were separated by the solvent fractionations such as hot water, cold & hot sodium hydroxide respectively, and their antimutagenic effects was determined against N-methyl-N'-nitro-N-cnitrso-guanidine(MNNG) using Salmonella typhymurium. There was no significant differencies of inhibition levels among the used media, but Ab-3 tractions still showed a high antimutagenicity in the Ames test regardless of cultivating areas or media. To prove the cell immunofunction, nitric oxide (NO) produced from Raw 264.7 matrophage cultured with three fractions (Ab-l, Ab-2, Ab-3) was measured, and showed generally increase about 45 ∼58 percent compared to another two media (rice straw plus sugar cane bagasse, rice straw only), in the fraction of hot alklai extracts of the fruiting body cultivated with P. thunbergiana, which means that the media selection could be very important factors for improving medicinal effects in agaricus blazei fruiting body.

A Study on Comparative Analysis of Socio-economic Impact Assessment Methods on Climate Change and Necessity of Application for Water Management (기후변화 대응을 위한 발전소 온배수 활용 양식업 경제성 분석)

  • Lee, Sangsin;Kim, Shang Moon;Um, Gi Jeung
    • Journal of Korean Society of societal Security
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    • v.4 no.2
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    • pp.73-78
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    • 2011
  • In order to resolve the problem of change in global climate which is worsening as days go by and to preemptively cope with strengthened restriction on carbon emission, the government enacted 'Framework Act on Low Carbon Green Growth' in 2010 and selected green technology and green industry as new national growth engines. For this reason, the necessity to use the un-utilized waste heat across the whole industrial system has become an issue, and studies on and applications of recycling in the agricultural and fishery fields such as cultivation of tropical crops and flatfishes by utilizing the waste heat and thermal effluent generated by large industrial complexes including power plants are being actively carried out. In this study, we looked into the domestic and overseas examples of having utilized waste heat abandoned in the form of power plant thermal effluent, and carried out economic efficiency evaluation of sturgeon aquaculture utilizing thermal effluent of Yeongwol LNG Combined Cycle Power Plant in Gangwon-do. In this analysis, we analyzed the economic efficiency of a model business plan divided into three steps, starting from a small scale in order to minimize the investment risk and financial burden, which is then gradually expanded. The business operation period was assumed to be 10 years (2012~2021), and the NVP (Net Present Value) and economic efficiency (B/C) for the operation period (10 years) were estimated for different loan size by dividing the size of external loan by stage into 80% and 40% based on the basic statistics secured through a site survey. Through the result of analysis, we can see that reducing the size of the external loan is an important factor in securing greater economic efficiency as, while the B/C is 1.79 in the case the external loan is 80% of the total investment, it is presumed to be improved to 1.81 when the loan is 40%. As the findings of this study showed that the economic efficiency of sturgeon aquaculture utilizing thermal effluent of power plant can be secured, it is presumed that regional development project items with high added value can be derived though this, and, in addition, this study will greatly contribute to reinforcement of the capability of local governments to cope with climate change.

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An Estimation of Land use by Land Values in the Great Cities - focusing on five great cities - (지가에 의한 대도시의 토지이용예측 - 5개 대도시를 중심으로 -)

  • Lee, Hyun-Wook
    • Journal of the Korean association of regional geographers
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    • v.7 no.1
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    • pp.83-95
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    • 2001
  • The purpose of this study is to examine that we can estimate land use by land values in 5 great cities. For this purpose, I calculated the percentage that each lot value makes up of the highest land values in the city as a indicator. I think this rate is very useful in the comparative study about many cities. At first, I set up four hypotheses based on my preceding studies. Hypothesis 1, the range of CBD can be estimated as having about 10% of the peak land values. Hypothesis 2, when the peak rate of concentric circle of land values seperated from CBD circle is about 30% of the peak land values, that is sub-CBD. Hypothesis 3, generally, a lot of having about 5% of the peak land values represents residential land commercial land use. Hypothesis 4, a lot of having about 3% of the peak land values represents only residential land use. The data on land values in five great cities were got from public notification on land values(1999) of the Ministry of Construction & Transportation. I selected highest lot values from many standard lot value in each Tong(the minimum administrative unit) in each cities. And I drew land values isopleth. Through that isopleth, I identified CBD cmd sub-CBD. Through the book of public notification on land values, I identified what land use are lots of having over 10%, about 5%, below 3% of the peak land values. As a result, we identified land use can be estimated by the percentage that each lot value makes up of the highest land values in the city. The bigger urban size becomes and the more stable land use becomes, the higher fitness of hypotheses becomes. The lowest degree of fitness about 4 hypotheses among 5 great cities showed in Inchon. Because Inchon lies adjacent to the greatest Seoul. The percentage that showed the lowest degree of fitness is 5% of the highest land values. The land use on lots of having about 5% of the peak land values is different from each other according to regional character in city.

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