• Journal of the Ergonomics Society of Korea
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• v.20 no.1
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• pp.15-29
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• 2001

This study was conducted to develop a prototype of adjustable desk and chair for students from elementary to high school. The development process started with identifying the problems of existing adjustable desks and chairs that are currently available in the market. The following fundamental design criteria were established and then applied to develop the prototype. The criterion of minimization of production cost yielding lower the market selling price was the most critically considered in view of the school furniture buyers' price-consciousness. Other design criteria used in this development were designing for stable and solid structure, requiring few motions and no tools to adjust, requiring the use of only one hand to adjust, unrestricting the adjustable interval, providing extra space for foot and knee area, reducing weight to move easily, and requiring not to move around for cleaning up floor. To evaluate the performance of the prototype, the adjustability of prototype was specifically compared with both dimensions suggested by KS G 2010(Korean Standards for desks and chairs for students) and current anthropometric dimension in terms of the flexible range of accommodation. Results of this study illustrate that the prototype developed in this study could be accommodated for the both dimensions. As a concluding mark, appropriate adjustable range for various grades and age groups were presented.

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.90-96
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• 2005

This paper presents the results of the reliability analysis of PAU (Preliminary Assembly Unit) seat of the floating Production Storage and Off1-loading Unit (FPSO) The main aim of the analysis was to demonstrate that a sufficient safety of structural members is guaranteed against PAU loads, internal and external pressure, and hull girder moments. Topside loads for PAU design are based on owner's request. According to the seat type, topside loads are classified into maximum values of same seat type for design efficiency. Totally, 26 loading cases for each model are used for this analysis with the combination of the reactions of PAU loafing and the hull girder bending moments according to LR offshore (2). The analysis results are evaluated according to the acceptance criteria for yielding given in LR offshore and guidance note (3) and The panel buckling resistance is verified by LR offshore and SDA (4). For 900,000 bbls FPSO, the PAU support foundation analysis using 3-D F.E. model is carried out to verify the structural adequacy of PAU foundation and structure members in way of PAU. The modified structures in way of PAU support are safe against considered load cases and all stresses in way of PAU support are within design criteria.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.285-292
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• 2004

The objective of this paper is to develop a simplified method to determine yield line patterns of reinforced concrete floor slabs based on the elastic fields. Unlike other methods mainly focused on the plasticity theory, this paper emphasizes the elastic fields, especially principal moments and maximum shears and shows a link between elasticity field and yield line patterns. General criteria on both positive and negative yield lines are suggested in terms of principal moments and maximum shear forces. The proposed method can predict starting point (or regions) of yielding and the further development of yield lines on whole structures. The yield line patterns determined by the proposed method are shown to be coincident with the classical yield line theory. Furthermore, orthotropy in reinforced concrete slab is investigated and yield line patterns for different type of flat slab with non-isotropic strip are studied broadly.

• Journal of Information Technology Services
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• v.4 no.1
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• pp.117-128
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• 2005

When we conduct development of a large-size SI project, it is highly necessary to utilize an appropriate application framework which helps to build a qualified software with high productivity in a short period of time. In this paper, we propose the architecture of a dynamically reconfigurable CBD application integration framework that has been used for developing large-scale e-business applications to achieve high development productivity and maintainability. This Integration framework can easily extend its functionalities, and dynamically change its configuration during run time according to the business category, such as applying interaction patterns among main components in software architecture, rules, policies, and environmental parameters. Dynamic reconfiguration has the feature to make applications be easily customized for changeable requirements. Through our application integration framework, huge sizes of contents can be managed according to the business category as well, by keeping configuration informations and huge volumes of source codes. In order to evaluate out application integration framework in terms of performance criteria, we present experimental results of throughputs from the framework by yielding dynamic configuration without any performance degradation.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.129-132
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• 1999

This paper deals with the optimal filtering problem constrained to input noise signal corrupting the measurement output for linear discrete-time systems. The transfer matrix H$_2$and/or H$_{\infty}$ norms are used as criteria in an estimation error sense. In this paper, the mixed $H_2/H_{\infty}$ filtering Problem in lineal discrete-time systems is solved using the LMI approach, yielding a compromise between the H$_2$and H$_{\infty}$ filter designs. This filter design problems we formulated in a convex optimization framework using linear matrix inequalities. A numerical example is presented.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06b
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• pp.60-66
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• 1998

The horizontal cold chamber pressure die casting produces a variety of net shape, complicate-geometry castings with desired mechanical properties. dimensional tolerance, and surface finish. However, top quality castings can be achieved only when optimal performance of thecold chamber (shot sleeve )and plunger is maintained druing the molten metla injection phase of the process. Unforturately, inreality , shot sleeves deteriorate fast and sometimes fail catastrophically due to incorrect design. These early and unexpected failures of shot sleeves cost die casters money and productiivity. To prevent promature failures of shoe sleeves major faulure mechanisms were investigated. with the aid of analyticla solutions robust design criteria for shot sleeves have been developed. The data directly obtained from failed shot sleeves in the die casting industry for automotive parts, support a strong correlation between design and filures. by applying these design criterial we expected premature faulures of shot sleeves can be avoided in die casting industry.

• Plant Resources
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• v.3 no.3
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• pp.206-210
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• 2000

A total of 20 soybean recommended varieties which were developed until late 1980's in Korea was evaluated at Suwon. Comprehensive evaluation and correlation analysis were conducted on the agronomic characters. Great variations were found in these genotypes for branch number, pod number, and grain yield per plant. The variation in number of pods/plant ranged from 53 to 164, and in grain yield from 25.9 to 68.8 g. The coefficient of variation for most of the characters had a wide range. In correlation coefficient, grain yield per plant showed a positive phenotypic association with weight of pods, pod number of branches, and weight of stem. Multiple regression analysis was done to formulate selection criteria. It indicated that stout and medium-stature genotypes with more branches, resulting in varieties with more pods per plant but with medium-size seeds are available to obtain high-yielding varieties.

• Earthquakes and Structures
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• v.14 no.1
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• pp.1-10
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• 2018

Seismic retrofitting of existing buildings and design of earth-quake resistant buildings are important issues associated with earthquake-prone zones. Use of metallic-yielding dampers as an energy dissipation system is an acceptable method for controlling damages in structures and improving their seismic performance. In this study, the optimal distribution of dampers for reducing the seismic response of steel frames with multi-degrees freedom is presented utilizing the uniform distribution of deformations. This has been done in a way that, the final configuration of dampers in the frames lead to minimum weight while satisfying the performance criteria. It is shown that such a structure has an optimum seismic performance, in which the maximum structure capacity is used. Then the genetic algorithm which is an evolutionary optimization method is used for optimal arrangement of the steel dampers in the structure. In continuation for specifying the optimal accurate response, the local search algorithm based on the gradient concept has been selected. In this research the introduced optimization methods are used for optimal retrofitting in the moment-resisting frame with inelastic behavior and initial weakness in design. Ultimately the optimal configuration of dampers over the height of building specified and by comparing the results of the uniform deformation method with those of the genetic algorithm, the validity of the uniform deformation method in terms of accuracy, Time Speed Optimization and the simplicity of the theory have been proven.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.117-120
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• 1998

Relationships of breeding values of sires for first lactation milk yield with pedigree information or indices were examined to identify the optimal criteria of selecting young dairy bulls for future use in artificial insemination (AI). Records of performance data on 1087 crossbred daughters (Holstein - Friesian, Jersey and Brown Swiss with Hariana) of 147 sires, generated at Livestock Production Research (Cattle and Buffaloes) Farm, IVRI, Izatnagar, U.P., during 1972 - 1995 were used to obtain the estimates of sire's breeding values (EBV) using the Best Linear Unbiased Prediction Procedures. The correlations between young bull's EBV and the dam's first lactation milk yield was non-significantly different from zero. However, the young bull's EBV was negatively and significantly related (r = - 0.275 ; P < 0.05) to the dam's best lactation milk yield, suggesting that the selection of young dairy bulls from high yielding elite dams is not a suitable criteria for genetic improvement. The correlations of sire's and paternal grandsire's EBV's with young bull's EBV were high and positive (0.532, 0.844; P < 0.01). The maternal grandsire's EBV was positively but non-significantly related to grandson's EBV. The pedigree index incorporating dam's milk records and sire's EBV's showed a negative and non-significant correlation with young bull's EBV. However, the correlation of a pedigree index $(I_3)$ combining information on sire's and paternal grand-sire's EBV's with young bull's EBV's was considerably high and positive (0.797; P < 0.01). The regression coefficients of young bull's EBV on pedigree index $I_3$, was higher than those on other pedigree information. These results revealed that there was no advantage in basing selection on dam's performance or maternal grand-sire's EBV and that sire's and paternal grandsire's EBV's were reliable pedigree information for selection of young dairy bulls for future use in AI.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.25-36
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• 1995

The application of the reliability analysis is investigated as a probabilistic approach to the assessment of ship's structural strength and to the establishment of design format for longitudinal strength. Reliability analyses are carried out for 34 ships of tankers and bulk carriers built in HHI for some failure modes such as tensile yielding, compressive buckling and ultimate strength of hull girder. The safety assessment of each ship, the calculation of sensitivity factors and the derivation of target reliability index are performed. As results. the difference of reliability indices among ships is great for all modes. To provide more uniform levels of safety the establishment of new strength criteria using partial safety factors is performed. The partial safety factors for the design format are obtained according to the AFOSM method and the reliability-conditioned(RC) method. Finally, a design format using partial safety factors has been proposed. We could find out that new strength criteria can produce consistent reliability indices which are close to the target value.