• Korean Journal of Soil Science and Fertilizer
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• v.41 no.4
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• pp.260-266
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• 2008

Small lysimeter experiment under rain shelter plastic film house was conducted to investigate the effect of soil characteristics on the leaching and soil solution concentration of nitrate and phosphate. Three soils were obtained from different agricultural sites of Korea: Soil A (mesic family of Typic Dystrudepts), Soil B (mixed, mesic family of Typic Udifluvents), and Soil C (artificially disturbed soils under greenhouse). Organic-C contents were in the order of Soil C ($32.4g\;kg^{-1}$) > Soil B ($15.0g\;kg^{-1}$) > Soil A ($8.1g\;kg^{-1}$). Inorganic-N concentration also differed significantly among soils, decreasing in the order of Soil B > Soil C > Soil A. Degree of P saturation (DPS) of Soil C was 178%, about three and fifteen times of Soil B (38%) and Soil A (6%). Prior to treatment, soils in lysimeters (dia. 300 mm, soil length 450 mm) were tabilized by repeated drying and wetting procedures for two weeks. After urea at $150kg\;N\;ha^{-1}$ and $KH_2PO_4$ at $100kg\;P_2O_5\;ha^{-1}$ were applied on the surface of each soil, total volume of irrigation was 213 mm at seven occasions for 65 days. At 13, 25, 35, 37, and 65 days after treatment, soil solution was sampled using rhizosampler at 10, 20, and 30 cm depth and leachate was sampled by free drain out of lysimeter. The volume of leachate was the highest in Soil C, and followed by the order of Soils A and B, whereas the amount of leached nitrate had a reverse trend, i.e. Soil B > Soil A > Soil C. Soil A and B had a significant increase of the nitrate concentration of soil solution at depth of 10 cm after urea-N treatment, but Soil C did not. High nitrate mobility of Soil B, compared to other soils, is presumably due to relatively high clay content, which could induce high extraction of nitrate of soil matrix by anion exclusion effect and slow rate of water flow. Contrary to Soil B, high organic matter content of Soil C could be responsible for its low mobility of nitrate, inducing preferential flow by water-repellency and rapid immobilization of nitrate by a microbial community. Leached phosphate was detected in Soil C only, and continuously increased with increasing amount of leachate. The phosphate concentration of soil solution in Soil B was much lower than in Soil C, and Soil A was below detection limit ($0.01mg\;L^{-1}$), overall similar to the order of degree of P saturation of soils. Phosphate mobility, therefore, could be largely influenced by degree of P saturation of soils but connect with apparent leaching loss only more than any threshold of P accumulation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.1-8
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• 2000

The objectives of this study were to investigate weather conditions which induced discolored grains and viviparous germination, and to evaluate yield responses following viviparous germination during mid- and late- ripening stage, the submergence during reproductive growth stage, and lodging in the yellow ripe stage. Weather conditions which caused glume discoloration at heading stage were 21.3-26.4$^{\circ}C$ in average temperature, 75.2-98.4% in relative humidity, 19.3 in transpiration coefficient and 10.8-13.8 m/sec. in wind speed. Yield reduction was 26-27% and 10~17%, respectively, when the glume discoloration rates were 63.2-65.7% and 38.3-45.2%, obviously due to the decrease in percent of fertile grain and ripening ratio. Weather conditions during continuous rain for 7 days were 96% in relative humidity, 18.9$^{\circ}C$ in average temperature, 21.9$^{\circ}C$ in maximum temperature, and 16.8$^{\circ}C$ in minimum temperature, causing the most viviparous germination in Juanbyeo(45.5%), followed by Jinbubyeo(14.5%), Bongkwangbyeo(14.2%), and Obongbyeo(12.6%). Lateral tillers started to occur when the submergence at the depth of 1.5-2 m lasted one day during the reproductive growth stage. The submergence for 2-3 days at 3-4 m of water depth induced 269-571 lateral tillers/m$^2$, supporting 32-52% of the total yield. The rice yield in the paddy fields which were left under the lodging conditions until harvesting was not different compared to that of the paddy fields which were kept upright by tieing them together after lodging, but perfect grain ratio decreased about 9.1% in the transplanting culture and 12.5% in the direct seeding culture on dry paddy field because of the increase in immature grains.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.1
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• pp.3642-3654
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• 1975

The purpose of this thesis is to derive a unit hydrograph which may be applied to the ungaged watershed area from the relations between directly measurable unitgraph properties such as peak discharge(qp), time to peak discharge (Tp), and lag time (Lg) and watershed characteristics such as river length(L) from the given station to the upstream limits of the watershed area in km, river length from station to centroid of gravity of the watershed area in km (Lca), and main stream slope in meter per km (S). Other procedure based on routing a time-area diagram through catchment storage named Instantaneous Unit Hydrograph(IUH). Dimensionless unitgraph also analysed in brief. The basic data (1969 to 1973) used in these studies are 9 recording level gages and rating curves, 41 rain gages and pluviographs, and 40 observed unitgraphs through the 9 sub watersheds in Nak Oong River basin. The results summarized in these studies are as follows; 1. Time in hour from start of rise to peak rate (Tp) generally occured at the position of 0.3Tb (time base of hydrograph) with some indication of higher values for larger watershed. The base flow is comparelatively higher than the other small watershed area. 2. Te losses from rainfall were divided into initial loss and continuing loss. Initial loss may be defined as that portion of storm rainfall which is intercepted by vegetation, held in deppression storage or infiltrated at a high rate early in the storm and continuing loss is defined as the loss which continues at a constant rate throughout the duration of the storm after the initial loss has been satisfied. Tis continuing loss approximates the nearly constant rate of infiltration (${\Phi}$-index method). The loss rate from this analysis was estimated 50 Per cent to the rainfall excess approximately during the surface runoff occured. 3. Stream slope seems approximate, as is usual, to consider the mainstreamonly, not giving any specific consideration to tributary. It is desirable to develop a single measure of slope that is representative of the who1e stream. The mean slope of channel increment in 1 meter per 200 meters and 1 meter per 1400 meters were defined at Gazang and Jindong respectively. It is considered that the slopes are low slightly in the light of other river studies. Flood concentration rate might slightly be low in the Nak Dong river basin. 4. It found that the watershed lag (Lg, hrs) could be expressed by Lg=0.253 (L.Lca)0.4171 The product L.Lca is a measure of the size and shape of the watershed. For the logarithms, the correlation coefficient for Lg was 0.97 which defined that Lg is closely related with the watershed characteristics, L and Lca. 5. Expression for basin might be expected to take form containing theslope as {{{{ { L}_{g }=0.545 {( { L. { L}_{ca } } over { SQRT {s} } ) }^{0.346 } }}}} For the logarithms, the correlation coefficient for Lg was 0.97 which defined that Lg is closely related with the basin characteristics too. It should be needed to take care of analysis which relating to the mean slopes 6. Peak discharge per unit area of unitgraph for standard duration tr, ㎥/sec/$\textrm{km}^2$, was given by qp=10-0.52-0.0184Lg with a indication of lower values for watershed contrary to the higher lag time. For the logarithms, the correlation coefficient qp was 0.998 which defined high sign ificance. The peak discharge of the unitgraph for an area could therefore be expected to take the from Qp=qp. A(㎥/sec). 7. Using the unitgraph parameter Lg, the base length of the unitgraph, in days, was adopted as {{{{ {T}_{b } =0.73+2.073( { { L}_{g } } over {24 } )}}}} with high significant correlation coefficient, 0.92. The constant of the above equation are fixed by the procedure used to separate base flow from direct runoff. 8. The width W75 of the unitgraph at discharge equal to 75 per cent of the peak discharge, in hours and the width W50 at discharge equal to 50 Per cent of the peak discharge in hours, can be estimated from {{{{ { W}_{75 }= { 1.61} over { { q}_{b } ^{1.05 } } }}}} and {{{{ { W}_{50 }= { 2.5} over { { q}_{b } ^{1.05 } } }}}} respectively. This provides supplementary guide for sketching the unitgraph. 9. Above equations define the three factors necessary to construct the unitgraph for duration tr. For the duration tR, the lag is LgR=Lg+0.2(tR-tr) and this modified lag, LgRis used in qp and Tb It the tr happens to be equal to or close to tR, further assume qpR=qp. 10. Triangular hydrograph is a dimensionless unitgraph prepared from the 40 unitgraphs. The equation is shown as {{{{ { q}_{p } = { K.A.Q} over { { T}_{p } } }}}} or {{{{ { q}_{p } = { 0.21A.Q} over { { T}_{p } } }}}} The constant 0.21 is defined to Nak Dong River basin. 11. The base length of the time-area diagram for the IUH routing is {{{{C=0.9 {( { L. { L}_{ca } } over { SQRT { s} } ) }^{1/3 } }}}}. Correlation coefficient for C was 0.983 which defined a high significance. The base length of the T-AD was set to equal the time from the midpoint of rain fall excess to the point of contraflexure. The constant K, derived in this studies is K=8.32+0.0213 {{{{ { L} over { SQRT { s} } }}}} with correlation coefficient, 0.964. 12. In the light of the results analysed in these studies, average errors in the peak discharge of the Synthetic unitgraph, Triangular unitgraph, and IUH were estimated as 2.2, 7.7 and 6.4 per cent respectively to the peak of observed average unitgraph. Each ordinate of the Synthetic unitgraph was approached closely to the observed one.

• Journal of Korean Medical classics
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• v.3
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• pp.218-247
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• 1989

As mentioned above, I got the next conclusion since I had considered the medical contents of the ancient period(上古時代) and the era of the old-Korea(古朝鮮時代) through several bibliographic records. 1. There were Pung-baeg(風伯), Uh-sa(雨師), Un-sa(雲師) that were the names of the governmental officials during the ancient period of Whan-ung(桓雄). Among them, Uh-sa specially managed the treatment for diseases. When we think of the significance of Pung(風)-which means the winds, Uh(雨)-which means the rain, Un(雲)-which means of clouds, we will find out that the human life will be affected by all kinds of phenomena of the nature. So I can infer that ancestries could prevent and treat diseases with adjusting them tn the changes in the weather. 2. There were five government officials(五事) in the ancient period of Whan-ung(桓雄上古時代). They are Uh-ga(牛加), Ma-ga(馬加), Ku-ga(狗加), Cheo-ga(猪加) and Yang-ga(羊加), and had charges of five important duties. Among them, Cheo-ga was set to a charge of treatment for diseases. So we can notice that there existed people who treated for diseases professionally. When we think of the meanings of Uh(牛)-which intends cows or bulls. Ma(馬)-which intends horses, Ku(狗)-which intends dogs, Cheo(猪)-which intends wild boars and Yang(羊)-which intends sheep, we can see that livestocks would be raised at that time, and they came to have more chances to digest meat. Since the digestion of meat became to be a burden on the stomach and the intestines, it might cause a lot of indigestive troubles. 3. When I compared Tan-gun Pal-ga(檀君八加) with the Oh-ga(五加) in the ancient period of Whan-ung(桓雄上古時代), I could tell that the community of Tan-gun's period is more advanced and specialized than one of Whan-ung's. When I think of the next sentence ; "The Prince Imperial, Bu-u(夫虞) become to be a Ro-ga(鷺加), who treat for diseases professionally.", I am sure that the treatment for diseases was more importment than any other things, because he was the third son of Tan-gun(檀君). 4. According to Tan-gun(檀君) mythology, Whan-ung(桓雄) came down from the heaven of the pure Yang(純陽) to the earth and then changed into a man who had had more Yang(陽) than Yin(陰). And a bear came up from the underground(or the cave) to the ground and then changed into a women who had had more Yin(陰) than Yang(陽). So both of them became to hold together. This story implicated that ancestors had taken a serious view of each of them, namely the ancestors didn't give the ascendance to the one side of them, and made much account of the mutual harmony. So I am sure that this fact coincided with the basic theories of oriental medical science. To refer to two proverbs of Tan-gun mythology that are "Ki-Sam-Chil-Il(忌三七日)" which means caring for twenty one days, and "Pul-Gyon-Il-Gwang-Baeg-Il(不見日光百日)" which means keeping indoors for one hundred days, I can tell you that "twenty-one-day" involves the principle of the birth of life, and "one-hundred-day" contains a preparatory period or the period of death to bear another life. 5. From the medical stuff, such as wormwood(艾), garlic(蒜), or wonder-working herbage(靈草), that had been written at the bibliographic papers of the ancient period(上古時代) and the era of the old-Korea(古朝鮮時代), I consider that many people might get a lot of women's diseases, indigestive troubles, and other diseases that were caused by the weakness, but with using various spices, such as the leaves of water pepper(蔘), they could prevent the occurrance of all kinds of diseases previously. So I regard this treatment as the medicine from food. 6. One of the sayings at Nae-gyong(內經) is that "The stone accupuncture(砭石) came from the orient." We can see both "wonder-wor-king wormwood(靈草)" and "dried wormwood(乾艾)" in the several bibliographic papers of the ancient history of the old-Korea(朝鮮上古史). From these records, I can be convinced that ancestors would utilize the acupuncture(針) and the moxa cautery(灸) to cure a patient of a disease. 7. Even though someone claimed that the book, "medical science and chemistry(醫學化學)" and "medical treatment(醫學大方)" had had been written during the ancient period of the old-Korea(上古朝鮮時代), such a fact can't have been ascertained historical evidence. But it has been handed down that there existed the original phonetic alphabet, such as the "Ka-Im-To alphabet(加臨土文字)" at that time. The terms about the diseases, which had been occurred at the community of the old-Korea(古朝鮮地域), were recorded fragmentarily at other records after that time. The origin of confucianism came from the race of the eastern barbarians, and Tae-Ho-Pok-Hi(太嗅伏義) and the king. Sun(舜) came from the eastern barbarians, too. The divination of tortoise shells at the country of Un(殷) is another from which was developed at the eastern barbarians' fortune-telling of animal bones. From these facts, I can infer that, by all means, they might record the medical knowledge which had been stored for thousands of years while contacting with china directly.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.283-296
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• 2014

The distribution of heavy metals in the stormwater runoffs from industrial sites around Shihwa Lake that implements the total pollutant load management system (TPLMS) was studied to characterize the temporal changes of metal concentrations and to assess the ecological risk in dissolved and particulate phases of the selected metals. The dissolved Co and Ni concentration demonstrated first flush and tended to decrease with increasing of the duration of rainfall. The intensity of precipitation was found to be the main controlling factor of particulate metals in the stromwater runoffs. The particulate concentration of Pb accounted for 97.2% so the particulate phase was its main form. Other metals followed the sequence: Pb>Cu>Cd>Co>Zn>Ni. The particulate-dissolved partitioning coefficient ($K_d$) indicated that the $K_d$ of Pb were bigger than that of other metals because the metal Pb in the stormwater runoffs is quickly removed into the particulate phase. In a single day rainfall event, total runoff fluxes for total metals as the sum of dissolved and particulate forms through only two sewer outlets were 2.21 kg for Co, 30.5 kg for Ni, 278.3 kg for Cu, 398.3 kg for Zn, 0.39 kg for Cd and 40.0 kg for Pb, respectively. Given the annual rainfall, the number of rain days and the basin area for total pollutant load management system (TPLMS) of Shihwa area, enormous amount of non-point metal pollutants were entered into Lake with any treatment. The dissolved metals (e.g., Ni, Cu and Zn) in the stormwater runoffs exceeded the acute water quality criteria. Additionally, all metals were significantly enriched in the particulate phase and exceeded the PEL criteria of sediment quality guidelines (SQGs). These results indicated that the heavy metals in the stormwater runoffs may pose a very high ecological risk to the coastal environments and ecosystem.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.75-85
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• 1998

Algal meal (cell) was produced from the solution of dairy cow wastes by fermentation of ulothrix. sp. and chlorella sp. Raw wastes mainly feces were diluted with ground water to give dry matter concentration of 0.5 w/v of wastes in 20 l amounts of ten plastic containers. Each containers were covered with plastic nets and vinyl films to protect from the insects and rain. Algea cells were harvested every 3 to 5 days and dried by sunlight and artifitial heat. Dried cells were ground by a feed meal, and analyzed and tested for the chemical composition of dry cell, in vitro DM and protein digestibility and the safty of algae. Protein contents in algae meals, ulothrix (29.37%) and chlorella (29.24%) were similar. However, chlorella contained lower Neutral detergent fiber (5.92%) than ulothrix(20,76%), and higher ash (32.86%) and calcium (12.62%) than ulothrix (28.66% and 6.09%) (P<.01). Ulothrix protein had higher for essential amino acids; valine, isoleucine and phenylalanine, than chlorella (P<.05). Algal fats contained high saturated fatty acids, C16:0 and C18:0, for ulothrix and high unsaturated fatty acids, C18:1 and C18:2, for chlorella (P<.01). In vitro digestibility of. ulothrix tended to be higher for DM, but lower for protein than chlorella. The weight gain and survival percentage were higher for pond fishes (loaches, Misgurnus sp. ) fed diet added chlorella meal than diets added ulothrix meal and control diet (P<.05).

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.4
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• pp.224-236
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• 2002

A long-term growth simulation was performed at 496 land units in the western coastal plains (WCP) of North Korea to test the potential adaptability of each land unit for growing South Korean rice cultivars. The land units for rice cultivation (CZU), each of them represented by a geographically referenced 5 by 5 km grid tell, were identified by analyzing satellite remote sensing data. Surfaces of monthly climatic normals for daily maximum and minimum temperature, precipitation number of rain days and solar radiation were generated at a 1 by 1 km interval by spatial statistical methods using observed data at 51 synoptic weather stations in North and South Korea during 1981-2000. Grid cells felling within a same CZU and, at the same time, corresponding to the satellite data- identified rice growing pixels were extracted and aggregated to make a spatially explicit climatic normals relevant to the rice growing area of the CZU. Daily weather dataset for 30 years was randomly generated from the monthly climatic normals of each CZU. Growth and development parameters of CERES-rice model suitable for 11 major South Korean cultivars were derived from long-term field observations. Eight treatments comprised of 2 transplanting dates $\times$ 2 cropping systems $\times$ 2 irrigation methods were assigned to each cultivar. Each treatment was simulated with the randomly generated 30 years' daily weather data (from planting to physiological maturity) for 496 land units in WCP to simulate the growth and yield responses to the interannual climate variation. The same model was run with the input data from the 3 major crop experiment stations in South Korea to obtain a 30 year normal performance of each cultivar, which was used as a "reference" for comparison. Results were analyzed with respect to spatial and temporal variation in yield and maturity, and used to evaluate the suitability of each land unit for growing a specific South Korean cultivar. The results may be utilized as decision aids for agrotechnology transfer to North Korea, for example, germplasm evaluation, resource allocation and crop calendar preparation.

• Korean journal of applied entomology
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• v.51 no.2
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• pp.99-109
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• 2012

Seasonal fluctuations of Riptortus pedestris were investigated in four regions including two sites each at Mt. Yangseong (Munui-myeon, Cheongwon-gun), O-chang (Cheongwon-gun), and Jujung-dong (Cheongju) using aggression pheromone traps from April to November in 2010 and 2011. Aggression pheromone and aggression pheromone + soybean traps were set at all investigated sites, and the Mt. Yangseong A and B sites were investigated at a farmland (80 m, asl) and forest (200 and 300 m). The population density of R. pedestris was high in mid June, mid August, and late October in 2010 and in early May, mid June, mid September, and early October in 2011 with trivoltine. O-chang and Jujung-dong populations, which were distinguished in farmlands and forests, were highest from June to August in the farmland and in September in the forest. Similar numbers of R. pedestris were capture in the farmlands and the forest in June-August, September-November, respectively. From the results of the four regions, more R. pedestris adults were captured in the aggression pheromone + soybean trap than that in the pheromone trap. To investigate the migration route by altitude, 500 R. pedestris adults marked with fluorescent paint were released and re-caught insects were counted in traps after 10 and 20 days. The pattern of the re-caught R. pedestris indicated migration from the forest to farmlands during April-June. These results suggest that the insects did not migrate in August because food was plentiful in the forest at 200 m, but they moved to the forest during October due to the scarcity of food and for overwintering. The R. pedestris seasonal fluctuations in 2011 were affected heavily by the environment, particularly rain precipitation.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.498-509
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• 1999

This study aims to clarify the effect of forest management practices(thinning and pruning) in forest hydrological processes on electrical conductivity to get the fundamental information on the facilitation of purifying water quality after forestry practices. Rainfall, throughfall, stemflow, soil and stream water were sampled at the study sites which consist of Abies holophylla and Pinus koraiensis in Kwangnung Experimental Forest for 6 months from March 1 to August 4, 1998. In case of deviding into forest hydrological processes, multiple regression equations of electrical conductivity and total amount of anion, $NO{_3}^-$ of throughfall, stemflow, soil water of management site in Abies holophylla shows high significance. And multiple regression equations of electrical conductivity and total amount of anion, $SO{_4}^{2-}$, $Cl^-$ of throughfall, stemflow, soil water of non-management site in Abies holophylla shows high significance. Multiple regression equations of electrical conductivity and $NO{_3}^-$, before non-rain days of throughfall, stemflow, soil water of management site in Pinus koraiensis shows high significance. And multiple regression equations of electrical conductivity and total amount of ion, $NO{_3}^-$, $K^+$, pH, total amount of anion of throughfall, stemflow, soil water of non-management site in Plinus koraiensis shows high significance. Multiple regression equations of electrical conductivity and pricipitation, total amount of ion, $Na^+$ of stream water in Abies holophylla and Pinus koraiensis shows high significance. In case of combining into forest hydrological processes, multiple regression equations of electrical conductivity and total amount of cation and anion, $Na^+$, $Cl^-$, and pH in rainfall, throughfall, stemflow, soil and stream water shows high significance.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.8-16
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• 2013

Currently, global warming has advanced by the usage of fossil fuels such as coal and petroleum. and the atmosphere temperature in the world of 100 years(1906~2005) has been risen $0.74^{\circ}C{\pm}0.18^{\circ}C$, IPCC announced that the global warming effect of last decade was nearly doubled compared to the changes($0.07^{\circ}C{\pm}0.02^{\circ}C$/10year) in the past 100 years. Moreover, due to the global warming, heat wave, heavy snow, heavy rain, super typhoon, were caused and are increasing to happen in the world continuously causing damages and destruction of social infrastructures, where concrete structures are suffering deterioration by long-term extreme climate changes. to solve these problems, the new construction technology and codes are necessary. In this study, to solve these problems, experiments on a variety of cases considering the temperature and humidity, the main factors of climate factors, were performed, and the cases are decided by temperature and humidity. The specimens were tested in compressive strength test and split tensile test by the curing age(3,7,28 days) morever, performance based design(PBD) method was applied by using the satisfaction curve developed from the experiment date. PBD is the design method that gathers the current experimental analysis and past experimental analysis and develops the material properties required for the structure, and carries out the design of concrete mix, and it is recently studied actively worldwide. Also, it is the ultimate goal of PBD to design and perform on structures have sufficient performance during usage and to provide the problem solving for various situations, Also, it can achieve maximum effect in terms of functionality and economy.