• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.2
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• pp.43-54
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• 1989

In this paper, measured and calculated responses are compared in order to give how the static and dynamic responses occurred in steel railway bridges due to train loads could be calculated appropriately. From this, it is investigated how the impact factors are varied by changing the train speed above 100km/h Field measurement is carried out by the steel strain gages and displacement transducers at the main design points, and then the static and dynamic response, fundamental frequencies, damping ratios and impact factors of the bridges are obtained. Static analysis is done using the computer program developed according to three dimensional matrix structural analysis in which the trains and bridges are modelled as 1,2 and 3 dimensions. Dynamic analysis is done according to 2 approaches, the moving force and mass problem. In moving force problem, the solutions are obtained by the modesuperposition-method and in moving mass problem by the direct integration method. From this study, it is known that in order to obtain the static response in the railway bridges, the bridge could be modelled by 1 or 2 dimension as in the highway bridge, however the response ratio(measured/calculaled) is high comparing to the highway bridges. By the way, the dynamic response should be obtained by the moving mass problem. And by comparing the measured and code specified impact factors, it is known that the factors specified in the present railway bridge code are very safe under the present service speed below 100km/h. However, because the factors become very high under the speed above 100km/h, especially in the simple plate girder bridge, it is thought that the code specification on impact factor should be discussed enough under the rapid transit system.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.11a
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• pp.7-7
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• 2001

The increasing interest in light weight materials coupled to the need for cost -effective processing have combined to create a significant opportunity for aluminum P/M. particularly in the automotive industry in order to reduce fuel emissions and improve fuel economy at affordable prices. Additional potential markets for Al PIM parts include hand tools. Where moving parts against gravity represents a challenge; and office machinery, where reciprocating forces are important. Aluminum PIM adds light weight, high compressibility. low sintering temperatures. easy machinability and good corrosion resistance to all advantages of conventional iron bm;ed P/rv1. Current commercial alloys are pre-mixed of either the AI-Si-Mg or AL-Cu-Mg-Si type and contain 1.5% ethylene bis-stearamide as an internal lubricant. The powder is compacted in closed dies at pressure of 200-500Mpa and sintered in nitrogen at temperatures between $580~630^{\circ}C$ in continuous muffle furnace. For some applications no further processing is required. although most applications require one or more secondary operations such as sizing and finishing. These sccondary operations improve the dimension. properties or appearance of the finished part. Aluminum is often considered difficult to sinter because of the presence of a stable surface oxide film. Removal of the oxide in iron and copper based is usually achieved through the use of reducing atmospheres. such as hydrogen or dissociated ammonia. In aluminum. this occurs in the solid st,lte through the partial reduction of the aluminum by magncsium to form spinel. This exposcs the underlying metal and facilitates sintering. It has recently been shown that < 0.2% Mg is all that is required. It is noteworthy that most aluminum pre-mixes contain at least 0.5% Mg. The sintering of aluminum alloys can be further enhanced by selective microalloying. Just 100ppm pf tin chnnges the liquid phase sintering kinetics of the 2xxx alloys to produce a tensile strength of 375Mpa. an increilse of nearly 20% over the unmodified alloy. The ductility is unnffected. A similar but different effect occurs by the addition of 100 ppm of Pb to 7xxx alloys. The lend changes the wetting characteristics of the sintering liquid which serves to increase the tensile strength to 440 Mpa. a 40% increase over unmodified aIloys. Current research is predominantly aimed at the development of metal matrix composites. which have a high specific modulus. good wear resistance and a tailorable coefficient of thermal expnnsion. By controlling particle clustering and by engineering the ceramic/matrix interface in order to enhance sintering. very attractive properties can be achicved in the ns-sintered state. I\t an ils-sintered density ilpproaching 99%. these new experimental alloys hnve a modulus of 130 Gpa and an ultimate tensile strength of 212 Mpa in the T4 temper. In contest. unreinforcecl aluminum has a modulus of just 70 Gpa.

• Journal of Distribution Science
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• v.13 no.11
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• pp.69-77
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• 2015

Purpose - Economic status at an early stage of life after one's retirement is often determined by the long-term sacrifice of one's earlier consumption tendencies. In general, the first and foremost way to secure income after retirement is through annuity savings. People sign up for personal annuity savings in order to guarantee a stable economic life upon retirement, and such actions may be heavily influenced by self-efficacy. Confidence in current economic activity is a source of rational decision-making. Inability to achieve self-control can lead to reckless spending and the eventual hindering of proper investment for the future. This paper examines how self-efficacy and self-control affect the intention and action of enrolling in an annuity savings plan in relation to one's level of financial literacy. Research design, data, and methodology - To analyze the proposed model, this study investigates financial consumers over the age of 20. The data were collected from 511 respondents and analyzed with SPSS 21.0 and AMOS 21.0. First, for the one-dimensional test and to measure the convergent validity of each structure, we use the scale purification process. The results of the test and the confirmatory factor analysis ensure the focus of the validity of the single dimension for each structure. In addition, the validity of the measurement was guaranteed from the results of correlation analysis. Results - First, self-efficacy and self-control have positive effects on the purchasing intention of the personal annuity savings plan. Second, purchasing intention positively affects purchasing behavior. Lastly, self-control has a positive effect on purchasing intention among the low financial literacy group, whereas self-efficacy does not have this effect in the high financial literacy one. Conclusions - The time of product benefit is different with age. The younger group would be granted the savings after several decades once they enroll, whereas the older group would wait for a relatively shorter period of time. Therefore, further research should be conducted in order to verify such a difference. However, this study has value through its confirmation that the roles of self-efficacy and self-control play a part in leading to the enrollment in annuity savings plans and by verifying different effects based on levels of financial literacy. Such results suggest a number of implications in a real life setting. First, banks need to put greater emphasis on the stability of annuity savings in general. Second, customers with relatively low levels of financial literacy are able to control their finances through annuity savings, but find self-efficacy difficult due to a lack of financial understanding. Therefore, such customers should be approached from an invest-effectiveness comparison method. Third, customers with high financial literacy tend to put more value in rational economic decision-making and behavior than in self-efficacy. Therefore, such customers should be approached by promoting the reliability of annuity savings and the excellence of the specific bank's annuity savings plan in comparison to those of other financial institutions.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.3 s.303
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• pp.81-90
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• 2005

When we transmit signals, which are quantized by the vector quantizer (VQ), through noisy channels, the overall performance of the coding system is very dependent on the employed quantization scheme and the channel error effect. In order to design an optimal coding system, the source and channel coding scheme should be jointly optimized as in the channel-optimized VQ. As a suboptimal approach, we may consider the robust VQ (RVQ). In RVQ, we consider developing an index assignment function for mapping the output of quantizers to channel symbols so that the effect of the channel errors is minimized. Recently, a VQ, which can reduce the encoding complexity and is called the sample-adaptive product quantizer (SAPQ), has been proposed. SAPQ has very similar quantizer structure as to the product quantizer (PQ). However, the quantization performance can be better than PQ. Further, the encoding complexity and the memory requirement for the codebooks are lower than the regular full-search VQ case. In this paper, SAPQ is employed in order to design an RVQ to channel errors by reducing the vector dimension. Discussions on the codebook structure of SAPQ and experiments are introduced in an aspect of robustness to noisy channels.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.513-519
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• 2006

We developed two kinds of the microchip for application to electrophoresis based on both glass and quartz employing the MEMS fabrications. The poly-Si layer deposited onto the bonding interface apart from channel regions can play a role as the optical slit cutting off the stray light in order to concentrate the UV ray, from which it is possible to improve the signal-to-noise (S/N) ratio of the detection on a chip. In the glass chip, the deposited poly-Si layer had an important function of the etch mask and provided the bonding surface properly enabling the anodic bonding. The glass wafer including more impurities than quartz one results in the higher surface roughness of the channel wall, which affects subsequently on the microflow behavior of the sample solutions. In order to solve this problem, we prepared here the mixed etchant consisting HF and $NH_4F$ solutions, by which the surface roughness was reduced. Both the shape and the dimension of each channel were observed, and the electroosmotic flow velocities were measured as 0.5 mm/s for quartz and 0.36 mm/s for glass channel by implementing the microchip electrophoresis. Applying the optical slit with poly-Si layer provides that the S/N ratio of the peak is increased as ca. 2 times for quartz chip and ca. 3 times for glass chip. The maximum UV absorbance is also enhanced with ca. 1.6 and 1.7 times, respectively.

• Journal of the Korean Institute of Gas
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• v.2 no.4
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• pp.60-66
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• 1998

The hot stove system is a process that is continuously and constantly generating the hot combustion air required for the blast furnace. The hot stove process is considered as a main energy consumption process because it consumes about $20\%$ of the total energy in steel making works. So, many researchers have interested in the improvement of the heat efficiency of the hot stove to reduce the energy consumption. But they have difficulties in improving the heat efficiency of the hot stove because there is no precise information on heat transformation occurring during the heating period. In order to model the relationship between the operating conditions and heat efficiencies, we propose a neural network using feature extraction as one of experimental modeling methods. In order to show the performance of the model, we compare it with Partial Least Square (PLS) method. Both methods have similarities in using the dimension reduction technique. And then we present the simulation results on the prediction of the heat efficiency of the hot stove.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.291-297
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• 2018

Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring $30{\times}17{\times}17cm$, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

• The Korean Journal of Emergency Medical Services
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• v.4 no.1
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• pp.35-46
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• 2000

The results of analyzing the cognition of CPR by college students who major in public health or not order to enhance the educational efficiency of first aid ability and its expansion are as follows. 1. In case of students majoring in public health, the students who have the knowledge of term 'CPR' are 95.3% of total 300 students and 62.6% of the students who don't major in public health know it. In the item test of examining the degree of theoretical knowledge of CPR, the cases who know all 12 items are 5.2% and 1.6% respectively in cases who major in public health and don't major in it and it is judged that the extension of educational opportunity for them should be urgent. 2. The students who have experienced the practice of CPR are 20.6% in case who major in public health and 7.4% in other case. Therefore it seems to desirable that indirect field experience should be obtained by strengthening practice centered education. 3. The order of practice to examine the CPR ability is asked and the students who show very good remark are just 21~22% in both cases and they conducted very ineffective CPR and it is examined that they did first aid which may a serious damage to patients. Then the cases who recovered pulse and respiration after CPR were very low as 28.8% in the students who major in public health and 35.7% in others. It is therefore considered that the exact education of conducting the maintenance of respiratory trace, artificial respiration and CPR is necessary. 4. The cases who had the education of CPR were 51% in the students who major in public health and 39.4% in others, who had little opportunities to have CPR and 92.5~93.2% in both groups fee the necessity of continuous education and it is very encouraging to extend the education of CPR. 5. The education of CPR is mainly done at school (70.3~79.4%) and from teachers (52.7~55.4%) and 71.2% of the students majoring in public health responded that it is good for them to have education of CPR at school and lecture by first-aider and 58.9% of others did it. The cases who ask for lecture by the Professors of Dept. of First-Aid are 11.8 in students majoring in public health and 13.1% in others and it is judged that lecture by them having the theoretical foundation and first-aider with practical ability will be desirable. 6. On teaching methods, 57.5% of the cases majoring in public health and 63.3% of others ask for practice and 20% of both groups need theory centered teaching. 7. On lecture fee, 83% of the cases majoring in public health and 83.3% of others consider it should be free and 8~11.8% who are to pay for 10,000 won and it is judged that it should be opened and operated as liberal arts by college in the dimension of lifelong education. 8. On the objects of education, 83% of cases majoring in public health and 66.6% of others consider it should be conducted in people of all ages and both sexes and it is known that everyone recognizes the necessity of popularizing the education of first-aid.

• Journal of the Korean Home Economics Association
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• v.32 no.5
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• pp.165-182
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• 1994

Korea's clothing industry which has been country's leading export industry and basic strategical industry is now faced with many difficulties both domestically and internationally. Domestically it is faced with continuing shortage of manpower in both production line and management high labour cost causing increase in price putting more weight on behavior of consumers resulting in change of industrial environment and continuing structural problems of industry itself. Internationally it is faced with strengthening of import regulations and protectionism of developed countries and rapid emergence of underdeveloped countries as leading exporting nations. In reality export plays the most essential role in our economy and is especially sensitive to the external environmental factors. Already economic bloc phonomenon can be seen everywhere and is continuing to accelerate in place such as E. U in Europ, North & South America as NAFTA, and South East Asian contries which recent tendency of economic unity effort is present. These countries of such economic blocs are imposing heavy custom duties reinforcing provision of country origin and acting out strict inspection regulations in order to protect the interest of their own industry. Therefore it is vital to manufacture excellent quality goods For these reasons study in this area has brought attention in Korea as well as worldwide in the recent years. Apparel industry which requires professional technology and ability is the most competitive international business. In order to challenge the international market the high level of intelligence is most required to produce high quality goods. The purpose of this study is to analyze the relationship between functions and roles of marketing and to approach problems in more efficient manner. Apparel industry is composed of various programs such as design pattern making merchandising and textile science. To succeed in the business is to give the highest satisfaction to the targeted market. Hence this study will example the factors that determine the Cost Quality and Performance of apparel products. The study will involve following steps; firstly establish relationship between the quality concept and productivity of apparel products Secondly inquire in to marketing strategy laying stress on apparel production related factors focusing on merchandising marketing production and operations Thirdly prospect 21st century apparel industry focusing on garment production and trade and also other countries structural improvement Fourthly establish the new dimension of competitive factors by grasping the actual circumstance of Korea's apparel industry in the international market. The research method will include; First reality approach method by analysing the present state of industry Second literal analysis such as marketing comparisons between leading apparel exporting countries.

• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.19-32
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• 2007

This paper present a new face recognition method based on LVQ neural net to construct a real time face recognition system. The previous researches which used PCA, LDA combined neural net usually need much time in training neural net. The supervised LVQ neural net needs much less time in training and can maximize the separability between the classes. In this paper, the proposed method transforms the input face image by PCA and LDA sequentially into low-dimension feature vectors and recognizes the face through LVQ neural net. In order to make the system robust to external light variation, light compensation is performed on the detected face by max-min normalization method as preprocessing. PCA and LDA transformations are applied to the normalized face image to produce low-level feature vectors of the image. In order to determine the initial centers of LVQ and speed up the convergency of the LVQ neural net, the K-Means clustering algorithm is adopted. Subsequently, the class representative vectors can be produced by LVQ2 training using initial center vectors. The face recognition is achieved by using the euclidean distance measure between the center vector of classes and the feature vector of input image. From the experiments, we can prove that the proposed method is more effective in the recognition ratio for the cases of still images from ORL database and sequential images rather than using conventional PCA of a hybrid method with PCA and LDA.