• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.327-332
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• 2001

It is generally observed that steel fiber reinforced concrete with traditional straight steel fibers overcomes brittle nature of plain concrete by failure mechanisms by fiber pull-out rather than fiber rupture resulting from fiber yielding or concrete fracture at failured surface. Ring type steel fibers in concrete which is confined in concrete matrix and has better orientation, thus, lead to fiber yielding and concrete fracture as well as increase of flexural behavior of concrete more efficiently, Comparative experimental study is performed in order to measure the relative efficiencies of steel fiber reinforced concrete reinforced with two different fibers. It is found that better toughness is obtained from the ring type steel fiber reinforced concrete than from straight steel fiber reinforced concrete under flexural loading.

• Journal of the Korean Home Economics Association
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• v.41 no.5
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• pp.89-97
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• 2003

Fitness of clothes becomes a major concern in apparel industry. But high-school boys had difficulties to buy ready-made clothes of good fit. To solve this problem, it is necessary to classify boys' upper body into several kinds of somatotypes. The purpose of this study was to classify upper body types of high school boys based on the analysis of their upper body types. The subjects for anthropometric measurement were 99 high school boys of 16 to 18 year-old. The result of factor analysis indicated that 5 factors were extracted from anthropometric measurements through analysis and those factors comprise 68.44% of total variance. 3 clusters were categorized using 5 factor scores by cluster analysis. Type 1 was taller than other types and was bending somatotype. Type 2 was straight somatotype and had average size. Type 3 was characterized by short and small figure and had bending somatotype.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.672-676
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• 2004

In this paper, measuring system of 5 DOF motion errors are proposed using two capacitive type sensor, a straight edge and a laser interfoerometer. Yawing error and pitching error are measured using the laser interferometer, and rolling error is measured by the reversal method using a capacitive type sensor. Linear motion errors of horizontal and vertical direction are measured using the sequential two point method. In this case, influence of angular motion errors is compensated using the previously measured angular motion errors. In the horizontal direction, measuring accuracy is within 0.05 $\mu$m and 0.27 arcsec, and in the vertical direction, it is within 0.15 $\mu$m and 0.5 arcsec. From these results, it is confirmed that the proposed measureing system is very effective to the measurement of 5 DOF motion errors in the ultra precision feed tables.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.233-239
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• 2007

The main objective of this study was to evaluate the effect of recycled PET fiber made from waste PET bottle on the control of plastic shrinkage cracking of cement based composites. PET is blown as a plastic material and used in a variety products such as a beverage bottle. However, waste PET bottles are thrown after the usage, raising huge problems in terms of the environment. Thus, the research on the method to recycle the PET bottles indicates important aspects in environment and economy. The method to recycle waste PET bottles as a reinforcing fiber for cement based composites is one of effective methods in terms of the recycle of waste PET bottles. In this research, the effect of recycled PET fiber geometry and length on the control of plastic shrinkage was examined through thin slab tests. A test program was carried out to understand the influence of fiber geometry, length and fiber volume fraction. Three type of recycled PET fibers including straight, twist crimped and embossed type. Three volume fraction and two fiber length were investigated for each of the three fiber geometry. Test results indicated that recycled PET fibers are effective in controlling plastic shrinkage cracking in cement based composites. In respect to effect of length of fiber, longer fiber was observed to have efficient cracking controlling with low volume fraction in same fiber geometry while shorter fiber controled plastic shrinkage cracking efficiently as addition rate increase. Also, embossed type fibers were more effective in controlling plastic shrinkage cracking than other geometry fiber at low volume fraction. But, for high volume fraction, straight type fibers were most effective in plastic shrinkage cracking controlling in cement based composites.

• Journal of the Korean housing association
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• v.17 no.4
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• pp.65-72
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• 2006

Most of buildings have been deteriorated with time-elapse by reflection of the building location, material, environmental circumstances and so on. The performance would go down and be demolished if anything could not be done after constructed. The maintenance should be required to preserve a decent living condition or improve a inferior condition by various plans and practices. The maintenance plan needs various data such as a repair scope, a repair time, a forecasted cost, a plan of management and so forth. Among the above required data for planning the maintenance, the deterioration characteristics of the building components would be first analyzed. The deterioration pattern would be a key role to affect and make a maintenance plan. In this paper, it aimed at classifying the deterioration patterns of building components. A deterioration pattern would be analyzed between the cumulative repair cost and time-elapse and modeled with these relations. A deterioration patterns are classified into 4 types-a accelerated type, a straight type, a temporary type and a slowly type. As a result of this research, a accelerated type includes window, window frame, general paintings, general water proofing in building components. A straight type includes the lacquer paintings, furnishings in building components and water supply pipe, boiler, sanitaries in mechanical facilities and lighting in electric facilities. Based on these research results, further study should be conducted to include any other components and an estimating model.

• The Journal of Korean Academy of Prosthodontics
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• v.11 no.1
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• pp.15-21
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• 1971

The prime objective of this study was to analyze the positional relationship of the lips to the anterior teeth according to age, sex, and both sides of the dental arch in 381 healthy Korean adults with normal occlusion ranging from 17 to 70 years over old. The results were as follows; 1. In the position of the corner of the mouth to the teeth, the range from center of canine to mesial side of first premolar was revealed the incidence of 81~87%, the distal side of canine was the hiqhest frequency of 39~43%. 2. A straight type (76~79%) of lip line was prevailed against the curved type in rest position. 3. In the exposed type of anterior teeth to upper lip in rest position, type III(50~52%) Grade 2 (26~29%) was revealed the highest frequency of occurences. 4. No significant difference in both sexes and sides of the dental arch was observed. 5. Lip position to the teeth with aging was showed the tendency toward straight type in lip line and toward reduction of the number of exposed type of upper anterior teeth to upper lip, and the corner of the mouth was placed posteriorly.

• Journal of the Korean Home Economics Association
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• v.34 no.2
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• pp.183-199
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• 1996

The objective of this study was to provide fundamental data on somatotype for elderly women by classifying the somatotype and analysing the 3 characteristics of their somatotype. The subject were 368 women of 60~84 years old, they were analyzed indirect photography. To find out differences among the age groups, the 368 subjects were grouped into two age groups (Group 1 ; age 60 to 69, Group 2 ; aged 70 to 84). Data were analyzed using Factor analysis, Cluster analysis, duncan test and Analysis of variance. Through the factor analysis, 27 items from photometric measurements respectively. Cluster analysis was applied for classification of somatotype. The results of this study were as follows. 1. The characteristics of Elderly women's somatotype were bending of the upper-torso, fatness of the waist and abdomen, drooping of the bust and shoulder and hip. In addition, height, girth, depth and width items were decreased in their sizes respectively. 2. The characteristics of clusters were as follows. Type 1 was straight somatotype in which the plumb line through tragion, the bust depth and under bust depth region laterally. Type 2 was swayback somatotype in which the upper portion of protruding point on the back was bent forward but the lower portion of protruding point had a characteristics of turning over somatotype. Type 3 was bending somatotype. Namely, this type was shorter than average and below the average fatness. Generally, the lateral view silhouette of elderly women was the straight type and changed into bending type as the age increases.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.319-324
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• 2001

This paper presents the motion control of a mobile robot with arc sensor for lattice type welding. Its dynamic equation and motion control method for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven along a straight line or corner. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider controls. For the torch slider control, the proportional integral derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the comer with range of $90^{\circ}$ constrained to the welding speed. The experiment has been done to verify the effectiveness of the proposed controllers. These results are shown to fit well by the simulation results.

• Journal of the Korean housing association
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• v.20 no.5
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• pp.9-21
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• 2009

This study classified visual perception types of access space at 17 five-star hotels in Jejudo and examined their cognitive characteristics and image formation structures in an effort to provide basic information important for designing the elevation and the access spaces of a hotel. The results of this study are as follows. Access space image of experimental hotels showed more negative evaluations at both city hotels and resort hotels, viewing angle (upward angle) was also positively evaluated between $10^{\circ}{\sim}12^{\circ}$ and $18^{\circ}$ and central type in arrangement type and detour access and straight access types in access circulation type were positively evaluated. When viewed from an upward angle of $10^{\circ}$ to $12^{\circ}$, the most important factors were as plasticity, decorativeness, and creativity; from $18^{\circ}$ it was such factors as harmony and peculiarity; and at $45^{\circ}$ it was factors like decorativeness and stability. In considering the various access types, the most important factors in a straight access type were peculiarity and harmony; for one-time curved access type it was by decorativeness, creativity, Peculiarity, and stability; and for detour access types it was decorativeness, stability, and peculiarity. Influential of factors affecting image formation and plasticity and harmony factors and the form had more influences on image formation.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.451-456
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• 1999

All the teaching items in a textbook are normally arranged in a prescribed teaching order. However, one can easily find that the textbooks of the same kind, even with the same teaching items, show different arrangements. Without learning preceding teaching items, students may have a difficulty in understanding the teaching items. In this sense, it is very important to decide how to arrange teaching items in terms of teaching sequence. As a solution to this problem, lsamu Matsubara presents a method based on the graph theory. The four types defined in his method are the straight type, the group type, the branch type, and the independent type. Among these, the three types except the straight type lack the objectivity. An objective solution to these three types, based on the fuzzy theory. is propopsed in this paper.