• Korean Journal of Ecology and Environment
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• v.34 no.1 s.93
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• pp.54-61
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• 2001

Changes in methanogenic pathway at low temperature were studied by incubation experiments of sediment slurries from the littoral zone of Reservoir Paldang. Methane production rates in sediment slurries increased exponentially between $5＾{\circ}C$and $45＾{\circ}C$, reached a maximum rate of $7.4\;nmol\;{\cdot}\;g^{-1}\;{\cdot}\;h^{-1}$ at $45＾{\circ}C$, and then declined to low rate. The shift of incubation temperature from high temperature ($30＾{\circ}C$) to lowtemperature ($15＾{\circ}C$) resulted in a decrease of methane production rate and of hydrogen accumulation rate, and the transient accumulation of acetate concentration. Chlorofarm inhibited perfectly methanogenesis and resulted in the accumulation of hydrogen and acetate as immediate precursors for metltane formation at both incubation temperatures of $15＾{\circ}C$ and $30＾{\circ}C$. In terms of equivalent methane which was calculated from the two intermediary metabolites accumulated in absence of methanogenesis, methane production from acetate was accounted for 14% of total methanogenesis at $30＾{\circ}C$ and 75% at $15＾{\circ}C$, respectively. When the high acetate concentrations above 19 mM were added to sediment slurries, methane production was inhibited at the low temperature ($15＾{\circ}C$) . Our results demonstrate that contribution of acetate on methanogenesis increases at low temperature, but this pathway is inhibited by high concentration of acetate. Therefore acetate-utilizing methanogensis appears to be a key reaction at low temperature, and seems to be one of bottlenecks of the low temperature anaerobic degradation of organic matter in littoral sediments of the reservoir.

• Korean Journal of Psychosomatic Medicine
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• v.28 no.1
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• pp.29-35
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• 2020

Objectives : Evidence regarding the association between untreated depression in adolescence and suicidal risk in male young adults is scarce. We aimed to assess the effect of untreated illness during adolescence on the suicidal risk and attempt after that first episode. Methods : As part of a cross-sectional study, between May 2017 and April 2018, a total of 260 patients with currently unipolar or bipolar depression were included in the final analysis. Multiple linear and logistic regression analysis were performed to evaluate the association between untreated mood disorder in adolescence and its effect on the suicidal risk and attempt. Results : In total 260 patients, 189 were classified as untreated group. The proportion of suicide attempts, total depression score, suicidal risk and number of suicide attempts were significantly higher in the untreated group. The most predictive factors of suicide attempts were history of untreated depression [Adjusted Odds Ratio (AOR)=4.19, 95% Confidence Interval (CI)=2.25-7.81, p<0.001] and diagnosis of bipolar depression (AOR=2.60, 95% CI=1.52-4.46, p<0.001). Conclusions : Although the untreated depression suggests higher rates of suicidality, a significant proportion (86.7%) of adolescent depression in this study did not receive psychiatric treatment. Future research should be needed to find better ways to decrease barriers in using mental health treatment and its contribution to reduction and prevention of adverse outcome.

• Agribusiness and Information Management
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• v.9 no.1
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• pp.7-17
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• 2017

Agricultural water management has gained enormous attention in the developing world to alleviate poverty, reduce hunger and conserve ecosystems in small-scale production systems of resource-poor farmers. The story of food security in the $21^{st}$ century in India is likely t o be closely linked to the story of water security. Today, the water resource is under severe threat. The past experiences in India in general and in Andhra Pradesh in particular, indicated inappropriate management of irrigation has led to severe problems like excessive water depletion, reduction in water quality, water logging, salinization, marked reduction in the annual discharge of some of the rivers, lowering of ground water tables due to pumping at unsustainable rates, intrusion of salt water in some coastal areas etc. Considering the importance of irrigation water resource efficiency, Krishna Western Delta (KWD) of Andhra Pradesh was purposively selected for this in depth study, as the farming community in this area are severely affected due to severe soil salinity and water logging problems and hence, adoption of different water saving crop production technologies deserve special mention. It is quite disappointing that, canals, tube wells and filter points and other wells could not contribute much to the irrigated area in KWD. Due to less contribution from these sources, the net area irrigated also showed declining growth at a rate of -6.15 per cent. Regarding paddy production, both SRI and semi-dry cultivation technologies involves less irrigation cost (Rs. 2475.21/ha and Rs. 3248.15/ha respectively) when compared to transplanted technology (Rs. 4321.58/ha). The share of irrigation cost in Total Operational Cost (TOC) was highest for transplanted technology of paddy (11.06%) followed by semi-dry technology (10.85%) and SRI technology (6.21%). The increased yield and declined cost of cultivation of paddy in SRI and semi-dry production technologies respectively were mainly responsible for the low cost of production of paddy in SRI (Rs. 495.22/qtl) and semi-dry (Rs. 532.81/qtl) technologies over transplanted technology (Rs. 574.93/qtl). This clearly indicates that, by less water usage, paddy returns can be boosted by adopting SRI and semi-dry production technologies. Both the system-level and field-level interventions should be addressed to solve the issues/problems of water management. The enabling environment, institutional roles and functions and management instruments are posing favourable picture for executing the water management interventions in the State of Andhra Pradesh in general and in KWD in particular. This facilitates the farming community to harvest good crop per unit of water resource used in the production programme. To achieve better results, the Farmers' Organizations, Water Users Associations, Department of Irrigation etc., will have to aim at improving productivity per unit of water drop used and this must be supported through system-wide enhancement of water delivery systems and decision support tools to assist farmers in optimizing the allocation of limited water among crops, selection of crops based on farming situations, and adoption of appropriate alternative crops in drought years.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.6
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• pp.64-76
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• 2014

This study identified the causes of errors that could take place in the estimation process of vehicle miles traveled and quantified the effects of each of those causes on the estimation accuracy of vehicle miles traveled via error rate to propose an efficient way to estimate vehicle miles traveled. The study proceeded as follows: first, the study established survey data of vehicle miles traveled in the pilot test areas to test the accuracy of a method to estimate vehicle miles traveled. Second, the causes of errors with the estimation of vehicle miles traveled were categorized into errors with the sample size, sampling methods, and homogeneous link setting methods. In addition, many different methodologies were set to minimize errors with the estimation of vehicle miles traveled according to each of the causes. Third, error rates of estimation of vehicle miles traveled were compared and analyzed according to each of the methodologies. Finally, a toy network was established to propose a way of estimating vehicle miles traveled by taking the local characteristics into consideration. The study finds its significance in that it proposed an efficient way to estimate vehicle miles traveled through an experiment and planning approach and made use of survey data of vehicle miles traveled to test estimation accuracy. The proposed way of estimating vehicle miles traveled by taking into account the local characteristics will make a contribution to the estimation of vehicle miles traveled by the areas in future along with the level of data offered in the study.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.4 no.1
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• pp.71-82
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• 1998

The purpose of this study is to analyze the phases of back pain occurring on pregnant women, and to raise the necessity of the pain management on the basis of the former analysis. The objective group is 284 pregnant women who visited department of OBGY of hospital located both in Seoul and Andong. The results are as follows; 1. 204(71.8%) pregnant women were suffering from back pain. The ratio of pain occurrance in terms of the duration of pregnancy shows that 78.3% within 3 pregnant months, 68.4% between four and six months and 72.1% over seven month. Most common ares of pain was low back area rating 60.5%. 2. The most painful postural for the suffering women was lying on the back rating 35.9% and the next painful posture was standing rating 34.4%. And the most painful movement was to maintaining continues movement(57.8%). Twisting back rates the second(17.2%). These two variables were relevant each other(p<0.05). 3. 46.7% of pregnant women were experiencing nocturnal pain. Among women experienced the pain before pregnancy, 39.9% were suffering during the pregnancy. The occurrence of nocturnal pain was related to the pain before and after the pregnancy(p<0.05). 4. 58.8% of pregnant women who experience back pain take the pain for granted as a normal proceeding of pregnancy while 3.9% recognize the symptom as an abnormal. Pain recognition in accordance with the phases does not show much difference(p<0.05). 5. It is shown that the more one delivers the number of babies, the faster back pain occurs(p<0.01). 6. 32.3% of the pain-suffering women have family member(s) having back pain. Family member(s) of the women who does not experience the pain don't have the pain either. This case reports 46.1%. Statistically, these two variables are relevant(p<0.01). 7. 43.0% of back pain experiencing women does not have any particular management plan against the pain. 20.7% is exercising as for prevention. Women who recognize the necessity of some means of therapy for their pain marked 42.9%. The majority(65.8%) of women responded exercise gymnastic work-out are most appropriate pain management. The above results show that a great number of pregnant women is experiencing back pain, however, they properly managed. This span suggests that appropriate advocacy and education for pregnant women is necessary. It is recommended that positive contribution can be made to better health of pregnant women when pain management by physical therapist is given.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.2 no.1
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• pp.266-295
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• 1974

The purpose of this study is to make a contribution to the effective management of medical literature in Korean libraries and specifically to help to select medical books and periodicals by determining the value and life of medical literature by means of citation counting and analysis. This report will present methods of calculation and data collection to measure the importance, half life of medical literature and the authority of author for Korean medical libraries. The writer conducted comparative studies based on data covering a two-year period, 1970-1971, using about 16,899 citations in 1,032 articles of the above journals. The references and citations are counted and analyzed by the number of authors, periodicals. books and publication dates. By the following ratio. calculated by the citation counting and analysis, we can decide the rates of medical periodicals to books, foreign literature to domestic literature and literature of the most numerously cited. authors, for the selecting method of Korean Medical libraries. (1) It is disclosed that 61 main authors are cited 9 times. Most of them are Western authors, they are cited 14,374 times which represents 88.6 % of the total citations. (2) The cited medical literature is classified as follows: The ratio of cited medical periodicals to the cited medical books is 82.0%. (The books at a rate of 18.0%.) Therefore, the wnter concentrated the efforts on the analysis of periodicals. (3) Classification of the periodicals by countries indicates that about 11.2% of total citations are made from Korean medical literature. The medical activities in Korea are dependent on the advanced foreign countries at ratio of 88.8%. Of the foreign medical periodicals cited, Japanese literature represents only 4.5% while literature of European countries and America constitutes 84.3%. (4) If medical journals are arranged in order of decreasing productivity of articles on a given subject, they may be revealed that it is necessary to have 98 titles of key journals to cover 60% of information in the field of medical science and 60 titles for an average of 50%. (5) For the purpose of measuring the life of medical literature in Korea, the writer has calculated the half lives of periodicals and books as follows: Kinds of Literature 1. Periodicals 2. Books 3. Whole literature Half-lives 7.75 years 4.11 years 6.37 years (6) The half lives of domestic and Japanese literature in the medical science are comparatively short.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.586-593
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• 2014

Newly reclaimed tidal land is known to be in low status of soil fertility. The incorporation of crop residue is an effective method to improve soil properties and fertility in reclaimed saline soils. The objective of this study was to evaluate the efficiency of rice straw (RS) application to improve physico-chemical properties of saline-sodic soil and its contribution to productivity of whole crop barley. Increasing rate of rice straw improved growth parameter related to yield of whole crop barley, which increased tiller number significantly (p<0.05).The yield increased by 15% (F.W) and 9% (D.W) in rice straw-amended plots. The content of soil organic matter (SOM) in the surface soil (0-20cm) with rice straw incorporation increased by 5~9% (RS 2.5~RS 7.5) compared to RS 0, in which the content of SOM decreased after two consecutive cultivations. Rice straw incorporation promoted soil physico-chemical properties and nutrient-availability of the test crop, as indicated in change in soil bulk density, porosity and increased nutrient uptake of plant. Especially, the P content and uptake of whole crop barley increased with increasing the rate of rice straw application. In conclusion, the rice straw application at rates of $5.0-7.5ton{\cdot}ha^{-1}$ in reclaimed saline soils effectively improved soil properties and crop productivity, which has potentials to reduce the loss of chemical fertilizers and facilitate the favorable condition for crop growth under adverse soil condition.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1567-1574
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• 2007

A study was carried out to study the response of total purine derivatives (PD) excretion in urine to determine microbial N (MN) supply at four fixed levels of feed intake (namely 95, 80, 60 and 40% of voluntary intake). The crossbred (CB) calves were allocated according to a $4{\times}4$ Latin Square Design and fed wheat straw and concentrate (1:1). The rate of PD excretion (mmol/d) as a linear function of feed intake was 15.85/kg DMI and 20.12/kg DOMI. Based on the endogenous and PD excretion rates obtained in this study, a relationship between daily urinary PD excretion (Y, mmol) and daily microbial protein supply (X, mmol) was developed for crossbred calves as Y = 0.83X+0.296 kg $W^{0.75}$. The derived microbial N values using this equation differed (p<0.001) among the 4 groups and was the highest in L-95 followed by L-80, L-60 and L-40. The relationship between urinary nitrogen loss (Y, g/d) and DOMI (X, kg/d) was established as: Y = 6.038X+21.753 ($r^2$ = 0.663, p<0.01). When urinary excretion of PD (Y, mmol/d) was plotted against intake of DM and DOM (X, kg/d), the equations obtained were: Y = 7.1711X+8.674 ($r^2$ = 0.889, p<0.01) and Y = 12.434X+7.683 ($r^2$ = 0.896, p<0.01), respectively. The proportional contribution of allantoin and uric acid to total PD remained stable irrespective of level of feed intake. Similarly, urinary excretion of creatinine did not differ (p>0.05) between animals fed at different levels. The MN supply was the highest to animals at intake levels L-95, and decreased linearly with corresponding decrease in feed intake. However, the MN supply when expressed per kg DOMI remained statistically (p>0.05) similar irrespective of level of intake. The results revealed that the excretion of urinary purine derivatives were positively correlated with the level of feed intake as well as rumen microbial supply and thus it could be a good indicator for measuring the microbial protein supply and nutritional status of animals.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.39-47
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• 2009

The METRO-K is a model for a radiological dose assessment due to a radioactive contamination in the Korean urban environment. The model has been taken part in the Urban Remediation Working Group within the IAEA's (International Atomic Energy Agency) EMRAS (${\mathbf{\underline{E}}}nvironmental$ ${\mathbf{\underline{M}}}odeling$ for ${\mathbf{\underline{RA}}}diation$ ${\mathbf{\underline{S}}}afety$) program. The Working Croup designed for the intercomparison of radioactive contamination to be resulted from the explosion of a radiological dispersal device in a hypothetical city. This paper dealt intensively with a part among a lot of predictive results which had been performed in the EMRAS program. The predictive results of three different models (METRO-K, RESRAD-RDD, CPHR) were submitted to the Working Group. The gap of predictive results was due to the difference of mathemathical modeling approaches, parameter values, understanding of assessors. Even if final results (for example, dose rates from contamintaed surfaces which might affect to a receptor) are similar, the understanding on the contribution of contaminated surfaces showed a great difference. Judging from the authors, it is due to the lack of understanding and information on radioactive terrors as well as the social and cultural gaps which assessors have been experienced. Therefore, it can be known that the experience of assessors and their subjective judgements might be important factors to get reliable results. If the acquisition of a little additional information is possible, it was identified that the METRO-K might be a useful tool for decision support against contamination resulting from radioactive terrors by improving the existing model.

• Computers and Concrete
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• v.22 no.3
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• pp.337-353
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• 2018

The present study focuses on examining the structural behaviour of steel-fibre-reinforced concrete (SFRC) beams under high rates of loading largely associated with impact problems. Fibres are added to the concrete mix to enhance ductility and energy absorption, which is important for impact-resistant design. A simple, yet practical non-linear finite-element analysis (NLFEA) model was used in the present study. Experimental static and impact tests were also carried out on beams spanning 1.3 meter with weights dropped from heights of 1.5 m and 2.5 m, respectively. The numerical model realistically describes the fully-brittle tensile behaviour of plain concrete as well as the contribution of steel fibres to the post-cracking response (the latter was allowed for by conveniently adjusting the constitutive relations for plain concrete, mainly in uniaxial tension). Suitable material relations (describing compression, tension and shear) were selected for SFRC and incorporated into ABAQUS software Brittle Cracking concrete model. A more complex model (i.e., the Damaged Plasticity concrete model in ABAQUS) was also considered and it was found that the seemingly simple (but fundamental) Brittle Cracking model yielded reliable results. Published data obtained from drop-weight experimental tests on RC and SFRC beams indicates that there is an increase in the maximum load recorded (compared to the corresponding static one) and a reduction in the portion of the beam span reacting to the impact load. However, there is considerable scatter and the specimens were often tested to complete destruction and thus yielding post-failure characteristics of little design value and making it difficult to pinpoint the actual load-carrying capacity and identify the associated true ultimate limit state (ULS). To address this, dynamic NLFEA was employed and the impact load applied was reduced gradually and applied in pulses to pinpoint the actual failure point. Different case studies were considered covering impact loading responses at both the material and structural levels as well as comparisons between RC and SFRC specimens. Steel fibres were found to increase the load-carrying capacity and deformability by offering better control over the cracking process concrete undergoes and allowing the impact energy to be absorbed more effectively compared to conventional RC members. This is useful for impact-resistant design of SFRC beams.