• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.248-255
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• 2006

Among a variety of influencing components, time-variant seepage and long-term underground motion are important to understand the abnormal behavior of tunnels. Excessiveness of these two components could be the direct cause of severe damage on tunnels. however, it is not easy to quantify the effect of these on the behavior of tunnels. These parameters can be estimated by using inverse methods once the appropriate relationship between inputs and results are clarified. Various inverse methods or parameter estimation techniques such as artificial neural network and least square method can be used depending on the characteristics of given problems. Numerical analyses, experiments, or monitoring results are frequently used to prepare a set of inputs and results to establish the back analysis models. In this study, a back analysis method has been developed to estimate geotechnically hard-to-known parameters such as permeability of tunnel filter, underground water table, long-term rock mass load, size of damaged zone associated with seepage and long-term underground motion. The artificial neural network technique is adopted and the numerical models developed in the firstpart are used to prepare a set of data for learning process. Tunnel behavior especially the displacements of the lining has been exclusively investigated for the back analysis.

• Journal of the Korean Dietetic Association
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• v.7 no.3
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• pp.237-247
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• 2001

The purpose of this survey was to investigate the status of dietitians' nutrition management and nutrition education in the elementary school lunch program. 386 dietitians in Kyungsangnamdo and Ulsan that participated in this survey, 350 dietitians were selected for analysis. The main results of this study are as follows. 80.6% don't survey the nutrition of home food, the reason is that 'too much work' 60.2%, - The more it increases the longer they have career record - 'botheration' 21.9%, 'no idea about process' 9.5%, 'no idea about way of survey' 8.4%. 23.5% don't survey the student's preferences, the reason is that firstly 'too much work' 55.1% ,secondly 'botheration' 34.7%, as well as the case of nutrition survey. The rate of nutrition education working is about 94%. The subject of education is mostly about 'advisable diet habit'(62.6%), then importance of nutrition(19.5%), elementary knowledge about food(10.0%), table manners (5.5%), sanitary and environment(24.6%). All(100%) of them who manage over 1501 works nutrition teachig while 83.0% do but 17.0% don't in a case of 401-800 at the relationship between whether they work education or not and how many students they manage.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.163-172
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• 2012

In this study, It is assumed that customers are both usage unit of spare parts and stores of displaying and selling the goods that are installation unit of having the spare parts. The demand pattern through the effective order of spare parts and issue list in installation unit is investigated based on the assumption. Current ASL (Authorized Stockage List) selection of the army has been conducted in the way of using the analysis result of real usage experiences on spare parts used during the Korea War. For this study, ASL selection criteria and procedures based on army regulations and field manuals are specified. Since the traditional method does not presents the association analysis on spare parts used for the current equipment operating and does not have the clear criterion and analysis system about the ASL selection, in order to solve these problems, it was carried out that the association rule is employed for analyzing relationship between the effective order and issue list of the spare parts in point of the spare parts between usage unit and occurring month about purchase spare parts based on the star-schema table. Finally the new ASL selection way using the analysis result is proposed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.36-49
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• 1998

The purpose of this study is to investigate the relationship between the work postures and upper extremity cumulative trauma disorders(CTDs) in female medical insurance bill reviewers(n=448). This study included diagnosis for CTDs, anthropometry and job analysis (workstations and posture). The characteristics of subject were 33.6 years of average age and 8.7 years of average work duration. The results were as fallows. Ergonomic conditions of workstation were unsuitable compared with anthropometry result. The height of work surface(79.5 cm) and chair(43.0 cm)were high. work space was small, and legs space under the table was limited. Work postures were awkward compared with recommended neutral postures. Neck flexion($21.0-36.0^{\circ}$), elbow elevation, shoulder abduction ($46.0-47.0^{\circ}$). wrist radial and ulnar deviation, forearm supination and pronation, and wrist repeated motion(12.7-21.5 freq./min) were analyzed as hazardous risk factors by job analysis. The prevalence of CTDs was 32.8 % by medical diagnosis. The prevalence rate of CTDs in hazardous work posture group was significantly greater than safe work posture group both neck-shoulder (relative prevalence = 5.2, p<0.001) and wrist-hand (relative prevalence = 2.5, p<0.05).

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.582-588
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• 2016

The hydrological simulation program FORTRAN (HSPF) is a comprehensive watershed model that employs the hydraulic function table (FTABLE) (depth-area-volume-flow relationship) to represent the geometric and hydraulic properties of water bodies. The hydraulic representation of the HSPF model mainly depends on the accuracy of the FTABLES. These hydraulic representations determine the response time of water quality state variables and also control the scour, deposition, and transport of sediments in the water body. In general, FTABLES are automatically generated based on reach information such as mean depth, mean width, length, and slope along with a set of standard assumptions about the geometry and hydraulics of the channel, so these FTABLES are unable to accurately describe the geometry and hydraulic behavior of rivers and reservoirs. In order to compensate the weakness of HSPF for hydraulic modeling, we generated alternate method to improve the accuracy of FTABLES for rivers, using the surveyed cross sections and rating curves. The alternative method is based on the hydraulics simulated by HEC-RAS using the surveyed cross sections and rating curves, and it could significantly improve the accuracy of FTABLES. Although the alternate FTABLE greatly improved the hydraulic accuracy of the HSPF model, it had little effect on the hydrological simulation.

• KCID journal
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• v.17 no.2
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• pp.17-27
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• 2010

In order to manage the water quality in reservoir, it is necessary to understand the temporal and spatial variation of reservoirs and to classify the reservoirs. In this research, agricultural reservoirs are classified according to physical characteristics (depth, residence time, shape of the reservoir etc) and water quality using multivatriate analysis (PCA and CA). CA (Cluster Analysis) method classify reservoirs into several groups as a similarity of the reservoirs, but it is difficult to indicate a full list to the one table. In case of PCA (Principle Component Analysis) method, it has the advantage for the classification on the reservoirs depending on the water quality similarity and also it is useful to analyze the relationship between related factors through correlation analysis. However PCA is limited to classify into several groups based on the characteristics of the reservoirs and each user should be classified as randomly subjective according to the relative position of the reservoir in the figure. In conclusions, compared to conventional reservoirs classification methods, both CA and PCA methods are considered to be a classification method that describes the nature of the reservoir well, but classification results has a restriction on use, so further research will be needed to complement.

• Water for future
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• v.18 no.1
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• pp.85-94
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• 1985

A method is developed for the separation of the major base flow in a river hydrograph combining the numerical techniques and the empirical methods. The linearized Boussinesq equation and the storage function are used to obtain the base flow recession. The shape of base flow curve made by the recharge of the groundwater table aquifer resulting from rainfall in determined by the Singh and Stall's graphical method, and the continuous from for the curve is approximated by the multiple and polynomial regression. this procedure was successfully tested for the separation of base flow and the establishment of hydrograph in a natural watershed. It was found that the direct numerical method applied to the homogeneous linear second order ordinary differential equation system is not suited to obtain the recession curve, and the case that the loss is generated in the partially penetrating stream can not be solved by the method of this study.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.273-277
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• 1998

The purpose of this study was to develop a large representative data base for jeans marketing strategy. This study was to survey brand awareness and analyze brand image and consumer's seeking image. The 700 questionnaires were distributed and 656 reliable ones were used for statistical analysis. A SAS statistical package including frequency table, factor analysis, analysis of variance, Duncan's multiple range test, Peason's correlation test was used. The results are as follows: 1. Brand awareness involves "brand recall" based on asking a person to name recalled first, and "brand recognition" based on asking to identify brand name from 30 given brands. The result indicated that "Levi" was dominant for brand recall and Guess was dominant for brand recognition. 2. Regarding the brand image, the result showed that "Vov" was best represented for sophisticated 8t trendy brand images, "Storm" for sophisticated brand image, "Jambangee" for reasonable price & comfortable brand images, and "Levis" for classic & design/color brand images. 3. As a result of factor analysis on consumer's seeking image, six factors(characteristic/gay, intelligent/sexy, feminine/sophisticated, active/functional, cute/young, simple/comfortable) were found. Several factors had a relationship with demographic variables, preferred design, fashion interest.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.2
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• pp.127-133
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• 2015

The error motion of a machine tool spindle directly affects the surface errors of machined parts. Those are usually due to the imperfectness of bearings, stiffness of spindle, assembly errors, external force or unbalance of rotors. The error motions of the spindle have been needed to be decreased to desired goal of spindle's performance. The level of error motion is needed to be estimated during the design and assembly process of the spindle. In this paper, the estimation method for the five degree of freedom (5 D.O.F) error motions for rotary units such as a spindle and rotary table are suggested. To estimate the error motions of the rotary unit, waviness of bearings and external force model were used as input data. The estimation model considers geometric relationship and force equilibrium of the five degree of the freedom motions.

• Journal of Biosystems Engineering
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• v.1 no.1
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• pp.49-54
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• 1976

No reliable basic data were available on the kinetic friction coefficients between grains and frictional surfaces being used in grain handling equipments in Korea. In order to determine appropriate kinetic friction coefficient between three grains (Tongil, Jinheung, barley) and two surfaces at four levels of moisture content of grain, the laboratory tests using the newly designed experimental apparatus and strain gage measuring system were carried out, and the relationship among factors that affect kinetic friction coefficients of grains were analyzed. The results of this study are summarized as follows ; 1. Kinetic friction coefficient of samples being tested was dependent on surfaces and moisture content of grains . The ranges of them were 0.369-0.512 for Tongil variety , 0.347-0.469 for Jinheung variety, and 0.360-0.502 for barley, respectively. 2. There was a little difference of kinetic friction coefficients between two varieties of rice at the same testing conditions. Because the interaction had been large among treatments , each value of kinetic friction coefficient determined in this study should be used only for the corresponding conditions in this study . 3. Kinetic friction coefficients in creased linearly with increase in moisture content of grains and their regression equations were shown in Table.4. 4. Kinetic friction coefficients on a PVC surfaces was shown a little lower values than on the steel surfaces at various moisture levels, but especially in Jinheung and barley, a big difference was shown.