• Journal of Korean Institute of Industrial Engineers
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• v.15 no.1
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• pp.65-75
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• 1989

This study complements the previous studies on workload distribution problems in Flexible Manufacturing Systems. Specifically, we consider the problem in two perspectives, the long-range policy and the short and medium-term planning and control. The long-term loading policy focusses on identifying the optimal loading of the system characterized by either balanced loading or unique unbalanced loading for which a steepest ascent method is developed. These results are then applied to study the optimal medium and short-term planning and control problems, for which a truncated dynamic programming method is developed in order to obtain the optimal allocation of the given operation mix of part types to work stations.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.133-139
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• 1997

Conventional concrete mixing method is to put all of the materials simultaneously into a mixer and mix for a required time. However, recently concrete researchers have reported that mixing sequence iufluences the properties of concrete. This study discusses the influence of mixing sequence and partitioning addition of mixing water. Concrete, by method of partitioning addition of mixing water, was found to have substantially stronger strength than conventional concrete with the same water-cement ratio. This means that a higher strength concrete could be obtained by using “Sand Enveloped with Cement”(S.E.C) mixing technique. Both a high bond strength between cement paste and aggregate, and elimination of bleeding both contribute to improving the strength of S. E. C concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.243-244
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• 2023

The quality of ready-mix concrete, a decisive factor in the performance of a structure, has recently been ensured by considering the unit water testing method, and this study experimentally examined the reliability of evaluation results based on this method.

• Smart Structures and Systems
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• v.19 no.5
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• pp.513-521
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• 2017

The purpose of this paper is to study the capabilities of the impulse response method in length and flaw detecting for concrete piles and provide a suggested method to find small-size flaws in piles. In this work, wavelet transform is used to decompose the recorded time domain signal into a series of levels. These levels are narrowband, so the mix of different dominant bandwidths can be avoided. In this study, the impulse response method is used to analyze the signal obtained from the wavelet transform to improve the judgment of the flaw signal so as to detect the flaw location. This study provides a new way of thinking in non-destructive testing detection. The results show that the length of a pile is easy to be detected in the traditional reflection time or frequency domain method. However, the small flaws within pile are difficult to be found using these methods. The proposed approach in this paper is able to greatly improve the results of small-size flaw detection within piles by reducing the effects of any noise and clarifying the signal in the frequency domains.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.86-93
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• 2001

This study presents about the method of alternatives selection by considering wall performance and interior design. Wall is selected fur the object and 3 items of cost, performance, and design as the objective function for optimizing are determined. Thus the wall performance selected problems, which are improvement of insulation performance, sweaty prevention, sound insulation performance and design selected problems, which is satisfactory Improvement of users about Interior design. It is important to select alternatives that can satisfy the performance and design on the capital given as much as possible. But quantitative problem such as performance or expanses and qualitative problem such as design are not in the same dimension. Therefore this problem is a multi-criteria optimization problem and also has used AHP method as the method to solve these. Moreover GA is used to solve a problem of the alternatives occurrence, which is the characteristic of multi-criteria problem. This study presents the solution method on multi-criteria problem that has been mix loaded of quantitative problem and qualitative problem by using AHP(Analytic Hierarchy Process) and GA(Genetic Algorithm).

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.66-75
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• 2009

The purpose of this paper is design and implement the invisible depth analysis tools. The developed algorithm was basically used reference plan method and to remove first step errors we mix-used point-to-point method. and we consider error due to curvature and refraction for large scale analysis. The final algorithm was developed as ArcToolBox tools, which can be considered convenient and public use as well; as result it reduced experimental errors as compared with conventional method and makes possible high resolution analysis for large scale site.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.4
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• pp.644-654
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• 2009

The purpose of this study is to analyze the characteristics of current fashion illustrations within the framework of Multi-space method. Multi-space means being piled up one moment & space on others, and being amassed in a scene. This method is related with Dadaism, Surrealism and Postmodernism, and also influences on the current fashion illustration. In this study, the types of Multi-space method could be classified into 4 types; Repetitive Time Mixture in Multi-space, Juxtaposed Time Mixture in Multi-space, Reiterated Space Mixture in Multi-space, Projected Space Mixture in Multi-space. The characteristics of Multi-space were analyzed and the results are as followed. The distinctive methods for Time Mixture in Multi-space are repetition and juxtaposition in a scene. Time Mixture in Multi-space can make the nonlinear narration and unreal illusory space in fashion illustrations more effectively. Reiterated Space Mixture in Multi-space can be related with the heterogeneous, surrealistic illusions in current fashion illustrations. Projected Space Mixture in Multi-space can be characterized into inter-penetration. It can derive spectators to mix the projected & transparent images in a scene for their own imaginary stories. The final imagination can be made differently according to the personal experiences of spectators.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.160-168
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• 2014

Objectives: Chemical hazard evaluations are important for workers' health and working environments. Allyl chloride (CAS No. 107-05-1) is used in many industries, leading to concerns about the possibility of threats to the health of workers. Since only insufficient or controversial information is available about potential related hazards, an in vitro mammalian chromosomal aberration (CA) assay was conducted in order to gain additional information concerning any such hazards. Moreover, toxicological information from this study could be applied for workers' rights to know, and to prepare or update the Materials Safety Data Sheet (MSDS) for a number of industries. Methods and Results: The assay was performed using the Chinese hamster lung fibroblast cell (ATCC, CRL-1935), by the direct method (-S9) and by the metabolic activated method (+S9 mix). Using the direct method, the seven dosages in the 48-hour treatment group did not show that the frequency of CA is proportionate to the dosage. The frequency of CA is not proportionate to the dosage addition for a six-hour treatment using the metabolic activated method. Conclusions: From these findings, it was decided that this chemical does not induce chromosomal aberrations under the tested conditions.

• Korean journal of food and cookery science
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• v.11 no.1
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• pp.13-19
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• 1995

The purpose of this study was to investigate the method of making whole Chinese cabbage Kimchi, the family's taste in Kimchi and the reason for disliking the taste of Kimchi in the Taegu area. The results were as follows; 1) Most housewives learned the method of making the Kimchi from their mothers. Method was as follows; First, scatter salt on the whole Chinese cabbage and soak that for 3∼6 hours. After, wash the whole Chinese cabbage 3 times. Then, add red pepper powder, garlic, ginger and salted fermented anchovy as basic seasoning. Be sure to, mix the red pepper powder and salted fermented anchovy until they taste hot and salty. Store the whole Chinese cabbage until they ferment. Afterwards store the whole Chinese cabbage in the refrigerator. 2) It was the whole Chinese cabbage Kimchi that most family members preferred. 3) Among the family members, the old age group preferred newly made Kimchi because of the cool and fresh taste. The adult group preferred fresh taste, also smell and peculiar taste of the seasoning were important. The adolescent group preferred fresh taste and sour taste. 4) It shows that most of the family likes Kimchi, and among the family members, about 25% of the sons and daughters dislike Kimchi. And it shows that all family members dislike salty taste. 5) The older housewives’ Kimchi was preferred over the younger housewives’ Kimchi.

• Computers and Concrete
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• v.32 no.2
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• pp.185-206
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• 2023

This article aimed to explore the optimization of mineral admixtures and retarding admixture for high-performance concrete. In essence, fresh concrete can be regarded as a mixture in which both coarse and fine aggregates are suspended in a cement-based matrix paste. Based on this view, the test procedure was divided into three progressive stages of binder paste, mortar, and concrete to explore their rheological behavior and mechanical properties respectively. At each stage, there were four experimental control factors, and each factor had three levels. In order to reduce the workload of the experiment, the Taguchi method with an L9(3⁴) orthogonal array and four controllable three-level factors was adopted. The test results show that the use of the Taguchi method effectively optimized the composition of high-performance concrete. The slump of the prepared concrete was above 18 cm, and the slump flow was above 50 cm, indicating that it had good workability. On the other hand, the 28-day compressive strength of the hardened concretes was between 31.3-59.8 MPa. Furthermore, the analysis of variance (ANOVA) results showed that the most significant factor affecting the initial setting time of the fresh concretes was the retarder dosage, and its contribution percentage was 62.66%. On the other hand, the ANOVA results show that the most significant factor affecting the 28-day compressive strength of the hardened concretes was the water to binder ratio, and its contribution percentage was 79.05%.