• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1861-1870
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• 2013

A climate change-driven increased hydrological variability has been widely acknowledged over the past decades. In this regards, rainfall simulation techniques are being applied in many countries to consider the increased variability. This study proposed a Homogeneous Hidden Markov Chain(HMM) designed to recognize rather complex patterns of rainfall with discrete hidden states and underlying distribution characteristics via mixture probability density function. The proposed approach was applied to Seoul and Jeonju station to verify model's performance. Statistical moments(e.g. mean, variance, skewness and kurtosis) derived by daily and seasonal rainfall were compared with observation. It was found that the proposed HMM showed better performance in terms of reproducing underlying distribution characteristics. Especially, the HMM was much better than the existing Markov Chain model in reproducing extremes. In this regard, the proposed HMM could be used to evaluate a long-term runoff and design flood as inputs.

• Korean Journal of Head & Neck Oncology
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• v.9 no.1
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• pp.74-87
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• 1993

Immunohistochemical studies on S-100 protein and lactoferrin were carried out to evaluate the existence and distribution pattern of S-100 protein and lactoferrin positive cells in salivary gland tumors. The specimens used were 25 cases of pleomorphic adenoma, 2 cases of monomorphic adenoma, 2 cases of mucoepidermoid tumor, 2 cases of acinic cell tumor, 3 cases of adenoid cystic carcinoma and 2 cases of adenocarcinoma occured in parotid and submandibular salivary gland. ABC kits(Dako corp. Copenhagen. Denmark) for S-100 protein and lactoferrin were used. The results obtained were summarized as follows: In the normal salivary gland. positive immunoreaction for S-100 protein was observed in myoepithelial cells of acini and intercalated ducts. Positive immunoreaction for lactoferrin was observed in serous acinic cells, epithelial cells of intercalated ducts, and excretory material in the ductal lumina. In the pleomorphic and monomorphic adenomas. most of tumor cells were positive for S-100 protein, while luminal tumor cells in gland-like or duct-like structures were rarely positive for lactoferrin. In mucoepidermoid tumor, most of squamous cells and a few of intermediate cells were positive for S-100 protein, but all of tumor cells were negative for lactoferrin. In acinic cell tumor, most of tumor cells were positive for lactoferrin, but all of tumor cells were negative for S-100 protein. In adenoid cystic carcinoma, basaloid tumor cells in trabecular structure were focally positive for S-100 protein. and in adenocarcinoma, many of tumor cells were posivive for both S-100 protein and lactoferrin. Thus, according to the embryonic stage of the development of the tumor cell origin, it was possible to classify the salivary gland tumor as followings: mucoepidermoid carcinoma which originated from the earliest stage, acinic cell tumor which originated from the end stage. Between these two extremes, there were pleomorphic adenoma, adenoid cystic carcinoma and adenocarcinoma which originated in the middle stage of the development of .the salivary glands. Based on the above results, it can be stated that S-100 protein is demonstrated in tumor cells orginated from myoepithelial cells and lactoferrin in glandular differentiated tumor cells.

• Journal of Korea Water Resources Association
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• v.45 no.11
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• pp.1081-1091
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• 2012

SWAT model is applied to simulate rainfall-runoff and pollutant loadings in the Nakdong River basin as the condition for extreme droughts and floods. The year 1994 and 2002 are chosen as the drought and flood year, respectively, through the analysis of past rainfall data for 30 years. The simulation results show decreases in both runoff and pollutant loadings for the drought year but increases for the flood year. However, the pollutant loadings on some upper sub-basins increase for drought year due to highly-regulated dam discharge and soil moisture change. Collectively, extreme droughts and floods have negative impacts on water quality, showing elevated SS loadings during wet season and concentrated T-P concentrations during low flow season. The extent of these impacts is highly influenced by antecedent dry days and precipitation patterns.

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.1-15
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• 1991

If one were to say that war is political in its nature, then war could be one of the several ways of achieving political goals. Thus, the aspect of wars will, in certainty, be altered by the changes in political environment. Wars in the past broke out mainly due to ideological differences that ran to extremes and were of high intensity. However, wars today show such restraints as controlling them beforehand or during the war in anticipation of the post-war situation. The trend of ideas to actualize such wars in the effective operation of airpower is on the rise. Airpower normally possesses speed and operative flexibility as well as capability of destruction, so it is possible to destroy the politically declared targets clearly. Previous airpower was merely employed as means of helping to vertically detouring the spatial obstacle that the ground forces encountered. Over the years, due to the speedy improvement of aviation technology and of ideas concerning wars in space, more advanced application has been developed. but they also were nothing more than an auxiliary role to facilotate the ground forces, that needed a longer effective range of firepower and did not become forces with the right of self-determination, that is, the fact of decisive war that makes its outcome. However, under transitional strategic environment like that of the present, Airpower possesses not only the capability to operate as a decisive means of war but also as theories to support it. The advancement in air technology has enabled supremacy over targets in depth, and the development of electronic technology has empowered the improvement of degree of destruction but also triumphant war by means of an overwhelming supremacy in a relatively short period. Thus, the method of systematic destruction that accomplishes the stated goals while rejecting the damage of accumulative destruction has been realized. The progress of such a concept has also proved that the counter-force strategy that has been developed in nuclear strategy is useful in conventional warfare as well. Therefore, it can be said that the under today's strategic environment airpower is an outstanding means of military strategy that can deeply affect to achieve the national objectives.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1149-1156
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• 2012

In this study, we proposed the most efficient driving posture based on the analysis of quantitative muscular strength and fatigue degree according to posture. Since driving include complicated actions required by a variety of ability and cause by extremes concentration or strain, drivers tend to feel tired easily. However, drivers can't recognize the fatigue degree by themselves. Moreover, the method for measuring the quantitative fatigue degree exactly is quite difficult to be secured. 9 professional bus drivers were participated. We analyzed the quantitative legs' muscular strength when operating each pedal. And then we also analyzed the muscular strength and muscular fatigue degree according to driving pattern during bus driving. Therefore, we suggested the most efficient driving posture.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.131-139
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• 1993

Low cycle fatigue characteristics of cast aluminum alloy A356 with a yield strength and ultimate strength of 229 and 283 MPa respectively was evaluated using smooth axial specimen under strain controlled condition. Reversals to failure ranged from 16 to 107. The cast aluminum alloy exhibited cyclically strain-gardening behavior. The results of low cycle fatigue tests indicated that the conventional low cycle fatigue tests indicated that the conventional low cycle fatigue life model was not a satisfactory representation of the data. This occurred because the elastic strain-life curve was not-log-log linear and this phenomena caused a nonconservative and unsafe fatigue life prediction at both extremes of long and short lives. A linear log-log total strain-life model and a bilinear log-log elastic strain-life model were proposed in order to improve the representation of data compared to the conventional low cycle fatigue life model. Both proposed fatigue life models were statistically analyzed using F tests and successfully satisfied. However, the low cycle fatigue life model generated by the bilinear log-log elastic strain-life equation yielded a discontinuous curve with nonconservatism in the region of discontinuity. Among the models examined, the linear log-log total strain-life model provided the best representation of the low cycle fatigue data. Low cycle fatigue life prediction method based on the local strain approach could conveniently incorporated both proposed fatigue life models.

• Computers and Concrete
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• v.17 no.5
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• pp.673-692
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• 2016

In the standards, minimum reinforcement ratios are presented as the least reinforcement ratios that bearing elements should have in a way to include all systems and in general. However, naturally these general minimum ratios might be presented as being lower than the normally required reinforcement ratios by criteria such as system size, bearing system arrangement, section situation and distributions of the elements and earthquake effect. In this case, minimum reinforcement ratios may remain as meaningless restrictions. Then grouping the criterion that might affect reinforcement ratios according to certain parameters and creating minimum reinforcement ratios regarding preliminary design will provide ease and safety during the project designing. Moreover, it will enable fast and simple examinations in the beginning of project control and evaluation process. By means of the data which could be defined as "preliminary design & minimum reinforcement ratios", a more realistic and safe restriction compared to general minimum reinforcement ratios could be presented. As a result of numerous comprehensive studies, reinforcement ratios to include all certain systems might be obtained. Today, thanks to the development level of finite elements programs which can make reinforced concrete modelling, with the studies that are impossible to carry out beforehand, this deficiency in the minimum reinforcement ratios in the standarts may at least be partially made up with the advisory regulation of preliminary design & minimum reinforcement ratios. As the structure of the system to be examined and the diversity of the parameters range from the specific to the general, preliminary design & minimum reinforcement ratios will approximate to general minimum reinforcement ratios in real terms. By focusing on a more specific system structure and diversity of the parameters, preliminary design and even design reinforcement ratios will be approximated. In this preliminary study, a route between these two extremes was attempted to be followed. Today, it is possible to determine suggested practical ratios for project designs through carrying out numerous studies.

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.314-324
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• 2000

Evaluation of nutritional status of the elderly imposes different problem from the other age groups. It is essential to use right instrument to assess food consumption. In Korea, the food frequency questionnaire has not been applied widely to elderly people. The purpose of this study is to assess the possibility of employing a semi-quantitative food frequency questionnaire(FFQ) for the Korean elderly to estimate nutrient and/or food intakes. In this study the FFQ for the elderly was developed and validated. The subjects were 144 free-living old women aged from 65 to 90. The FFQ was designed with 4 items for cereals and 86 items for other foods and with frequency of 12 intervals. Three portion sizes were given to select : 1/2 of standard amount, standard amount, and 11/2 of standard amount. ach subject was interviewed with newly developed FFQ form and same subjects were also involved to complete 3-day diet record. Nutrient intake was calculated using software program developed by our group. The nutrient intakes by the FFQ was validated by comparing the results with 3-day diet record. The FFQ estimated significantly higher mean intakes of energy, carbohydrate, protein, fats and vitamin C than did the diet reconrds(p<0.05). Pearson's correlation coefficients between two methods ranged from 0.21 for vitamin Q to 0.69 for alcohol(mean r=0.53). From 32% to 42% of the subjects were classified in the same quintile of nutrient intake by two methods, and 63% to 84% were classified in the same or adjacent quintile. On average, only 4% of the subjects were misclassified into extreme quitiles. The results indicate that the FFQ developed for the elderly in this study is useful for classifying individuals by rank and identifying groups at extremes of nutrient intakes.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.17-22
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• 2008

Including heat wave, Climate change caused 150,000 casualty in 2000 and heat waves are meteorological events that pose a serious threat to human health. A heat wave is defined as "a period of abnormally and uncomfortably hot and usually humid weather". There is a need for the prevention of health effects due to weather and climate extremes. This study intends to propose the necessity of Response System to correspond to extreme heat. And this research focused on Cooling Center manual of facility and maintenance for extreme heat disaster. It would be useful to be planned based on community and to be taken a role as an E.O.C.(Emergency Operating Center). As a conclusion elderly watching system and the requirements regional cooling center facility was proposed.

• Proceedings of the KSRS Conference
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• v.2
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• pp.752-755
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• 2006

Evaportranspiration is an important factor in hydrology cycle. Traditionally, it is measured by using basin or empirical formula with meteorology data, while it does not represent the evaportranspiration over a regional area. With the advent of improved remote sensing technology, it becomes a surface parameter of research interest in the field of remote sensing. Airborne and satellite imagery are utilized in this study. The high resolution airborne images include visible, near infrared, and thermal infrared bands and the satellite images are acquired by MODIS. Surface heat fluxes such as latent heat flux and sensible heat flux are estimate by using airborne and satellite images with surface meteorological measurements. We develop a new method to estimate the evaportranspiration over the rice paddy. The surface heat fluxes are initialized with a surface energy balance concept and iterated for convergent solution with atmospheric correct functions associated with aerodynamic resistance of heat transport. Furthermore, we redistribute the total net energy into sensible heat and latent heat fluxes. The result reveals that radiation and evaporation controlled extremes can be properly decided with both airborne and satellite images. The correlation coefficient of latent heat flux and sensible heat flux with corresponding in situ observations are 0.66 and 0.76, respectively. The relative root mean squared errors (RMSEs) for latent heat flux and sensible heat flux are 97.81 $(W/m^2)$ and 124.33 $(W/m^2)$, respectively. It is also shown that the newly developed retrieval scheme performs well when it is tested by using MODIS date.