• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1461-1468
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• 2015

Mostly mine support(Rock bolt and Support) which is currently general for reinforcements of a large scale tunnel is applied, Some executing a reinforcement to Poor ground by cast-in-place shotcrete. However On domestic mine conditions that couldn't having every time after mine tunnel excavation, it couldn't ensure the field batch plant which is a fixed in an issue of economies and site security, constructing it by supply gets from shotcrete materials combined in neighborhood ready mixed concrete manufacturing plants. carried shotcrete in ready mixed concrete manufacturing plants as migration length and time are falling off in quality. But, it is difficult for construction quality control By quality control arbitrariness absence at on-scene. In the present study, carry out Laboratory Test by kinds and percentages of accelerating agent for evalution of Mechanical Property and Durability of Shotcrete.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.57-63
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• 2018

IoT devices are used in many areas to perform various roles and functions in a cloud environment. However, a method of access control that can stably control the IoT device has not been proposed yet. In this paper, we propose a hierarchical multi-level property access control scheme that can perform stable access of IoT devices used in a cluster environment. In order to facilitate the access of the IoT device, the proposed method not only provides the ID key (security token) unique to the IoT device by providing the IoT Hub, but also allows the IoT Hub to authenticate the X.509 certificate and the private key, So that the private key of the IoT device can not be seen outside the IoT device. As a result of the performance evaluation, the proposed method improved the authentication accuracy by 10.5% on average and the processing time by 14.3%. The overhead of IoT Hub according to the number of IoT attributes was 9.1% lower than the conventional method.

• Journal of Family Resource Management and Policy Review
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• v.13 no.3
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• pp.181-205
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• 2009

The purpose of this study is to investigate some Influencing factors related to the wealth perception and property increase of 519 women in Seoul. The research was conducted from the end of February 15 to the beginning of January 20, 2009. The figures obtained were analyzed by frequency, percentage, mean, x-test, t-test, F-test, chi-square, and Duncan's F-test with SPSS pc+ The major findings of who study are summarized as follows: l.There were significant differences between the wealth recognition (economic plan affirmative and negative perception of wealth) for women according to social and psychological variables; economic plans have a higher value for married women, older women, those who have followed a postgraduate university course, those with higher income and expenditure, higher life satisfaction, and high and middle satisfaction with their economic life. In particular, economic plans varied significantly according to expectation of wealth in old age, and future economic prospects in the middle group. 2. Increased wealth and economic according to social and psychological variables (marital status, age, education, income, expenditure, life satisfaction, satisfaction with economic life, expectation of wealth in old age, future economic prospects) were shown to be associated with the following methods of increasing property: use of savings banks (p<.001) showed a rate of deposit of 20%-40% (p<.001) saving and thrift was a practice (p<001) that was related to the cost of living; and education expenditure (p<.001) as a property preparation period was exhibited in women aged 25-30 (p<.001). 3. There were significant differences in the recognition of wealth according to strategies for increasing wealth. There were no significant differences between mean of property acquisition and point of expenditure or the property preparation period in the perception of wealth. The related variables in rate of deposits were under 20% according to economic plan and negative wealth perception. In contrast, in the middle and high group, the economic plan and negative wealth perception were 20%-40% in relation to the rate of deposits. Variables related to the action of saving and thrift and property acquisition were practiced in the low and middle group of affirmative wealth recognition and the high group of negative wealth perception. The high group for wealthrecognition and the low group for wealthnegation exhibited little savings, thrift, and property accumulation. Those variables which point an expenditure the cost of living were education expenditure in all groups of negative wealth perception. The women in the study practiced more soundness economic planning according to their increased wealth and economic strategy. This study suggests that women should have positive wealth perception in their lives.

• Journal of Internet of Things and Convergence
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• v.6 no.3
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• pp.75-80
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• 2020

Recently, the size of the IoT sensor has been decreased and the collecting direction of the IoT sensor for acquiring the data have been changed from 2D to 3D. It makes sensor structure complex. In the fabrication of the complex structure, 3D printing technology has more useful than traditional manufacturing technologies. Among 3D printing technologies, FDM (fused deposition modeling) is a candidate technology to fabricate a small IoT sensor because the price of the machine and the material is cheap. In the FDM process, a 3D shape is made by depositing the melted filament. Recently, the patent of FDM technology is expired and cheat machines are developed based on the open-source. In the FDM process, mechanical properties of a fabricated part is affected by a lots of factors such as the kind of material and process parameters. Among them, infill is affecting the mechanical properties and the production lead time as well. In this work, a new method to optimize the FDM process with the consideration of mechanical property and production lead time was proposed. To verify the method, the fabrications were performed with the different infill rates. The results of tensile tests were analyzed to verify the proposed method.

• Korean journal of food and cookery science
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• v.31 no.6
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• pp.741-748
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• 2015

This study evaluated the effects of adding blood levels to phycochemical properties, textural properties, and sensory characteristics of blood sausage. 4 treatment groups of blood sausage were produced, T1 (pork ham : pork blood = 60:15), T2 (55:20), T3 (50:25), and T4 (45:30). T1 had the highest moisture content, most cohesiveness, and gumminess, CIE L-value, CIE a-value, and CIE b-value of raw and cooked blood sausages. Protein content, fat content, ash content, and VBN values were not significantly different among the treatments. T4 was treated with the most added pork blood, and had the highest pH of raw and cooked blood sausages, cooking loss, and TBA values. T2's sausage was the hardest, but had more springiness, cohesiveness, gumminess, and chewiness than T4. The best scores were from T4 and had the most overall acceptability. The results of this study show that blood sausages containing 20% pork blood had higher improved quality characteristics in blood sausages.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.9_10
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• pp.1453-1464
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• 2007

The purpose of this study is to examine the hand of spring/fall fabrics for 'Saenghwal Hanbok' on subjective hand, objective hand and the preference. In this study, 28 varieties of spring/fall fabrics such as cotton fabrics, synthetic fabrics, blended fabrics and a silk fabric for 'Saenghwal Hanbok' are used. To evaluate the subjective hand of fabrics, the holistic touch and preferences, 33 seven ranks' segmentic differential scale questions are developed with adjective pairs and are gathered by surveying experts on clothes. The mechanical properties, HV and THV of them are measured and calculated by KES-FB system. Through subjective hand, items could be classified into six hand expressions: 'bulky/extensibility', 'stiffness', 'feeling of weight', 'surface property', 'drapability' and 'moisture property'. Through mechanical properties, the results indicated that the character of cotton fabrics are slight flexible, tough, rough, uneven, a bit heavy, thick and low resilience on tensile and compression, and then those of synthetic fabrics, blended fabrics and a silk fabric are thin and light, smooth, flat and bulkless. In correlation on subjective evaluations and the preference for 'Saenghwal Hanbok', cotton fabrics mainly depend on 'surface property' and 'moisture property' and then synthetic fabrics, blended fabrics and a silk depend on 'bulky/extensibility' and 'surface property' In correlation on objective hand and the preference for 'Saenghwal Hanbok'. people aren't satisfied with low resilience. high stiffness and low drape.

• Journal of Korea Foundry Society
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• v.36 no.2
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• pp.67-74
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• 2016

The effects of scrap content on the hot tearing property and tensile property were investigated in AC2BS alloy. The hot tearing strengths were $16.4kgf/cm^2$, $15.2kgf/cm^2$, $14.9kgf/cm^2$ and $13.3kgf/cm^2$, respectively, under the constant solid fraction of 29.3% when the scrap contents of the specimens were 0%, 20%, 35% and 50%. In the same way, tensile strengths of the as-cast condition were $24.5kgf/mm^2$, $23.7kgf/mm^2$, $17.3kgf/mm^2$ and $16.0kgf/mm^2$, respectively, and the corresponding tensile strengths of the T6 heat treatment condition were $27.2kgf/mm^2$, $26.7kgf/mm^2$, $24.2kgf/mm^2$ and $23.9kgf/mm^2$. Hot tearing strength and tensile strength decreased as scrap content of the specimen increased. According to the evaluation of the quantitative hot tearing and tensile test results, the decrease of these strengths is due to the presence of oxide films which act as crack initiation site of the specimens. Therefore, elimination of oxide films of aluminum melt to maintain melt cleanliness is required.

• Bulletin of the Korean Mathematical Society
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• v.50 no.1
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• pp.161-173
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• 2013

This paper is concerned with the space $\mathcal{K}_{w^*}(X^*,Y)$ of $weak^*$ to weak continuous compact operators from the dual space $X^*$ of a Banach space X to a Banach space Y. We show that if $X^*$ or $Y^*$ has the Radon-Nikod$\acute{y}$m property, $\mathcal{C}$ is a convex subset of $\mathcal{K}_{w^*}(X^*,Y)$ with $0{\in}\mathcal{C}$ and T is a bounded linear operator from $X^*$ into Y, then $T{\in}\bar{\mathcal{C}}^{{\tau}_{\mathcal{c}}}$ if and only if $T{\in}\bar{\{S{\in}\mathcal{C}:{\parallel}S{\parallel}{\leq}{\parallel}T{\parallel}\}}^{{\tau}_{\mathcal{c}}}$, where ${\tau}_{\mathcal{c}}$ is the topology of uniform convergence on each compact subset of X, moreover, if $T{\in}\mathcal{K}_{w^*}(X^*, Y)$, here $\mathcal{C}$ need not to contain 0, then $T{\in}\bar{\mathcal{C}}^{{\tau}_{\mathcal{c}}}$ if and only if $T{\in}\bar{\mathcal{C}}$ in the topology of the operator norm. Some properties of $\mathcal{K}_{w^*}(X^*,Y)$ are presented.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.3
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• pp.165-169
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• 2007

Prediction of fatigue duration is attainable from the analysis of the growth rate of the fatigue crack, and the property of the fatigue crack growth is determined by the calculation of the stress intensity factor. And the evaluation of the stress intensity factor, K comes from the stress analysis of the vicinity of crack tip of the continuum. This study describes a simple method to decide the stress intensity factor for the small crack at the sharp edge notches. The proposed method is based on the similarities between elastic stress fields of the notch tip described by two parameters, the stress concentration factor K, the radius of arc of the notch. And it is applicable to the analysis of the semi-elliptical penetration cracks and the edge notches.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.4
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• pp.201-206
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• 2007

Most of the fatigue fractures of various machine structures start at discontinuities or small defects. In this study property of crack growth of titanium alloy was also analyzed to investigate the difference compared with the carbon steel. Titanium alloy has very high specific strength, and the material is widely utilized in advanced engineering fields such as aerospace, atomic energy and ocean development because of its excellence in corrosion and heat resistance. Generally the machine structures experience irregular loadings rather than periodic forces. The prediction of the fatigue life therefore has been analyzed to provide fundamentals of the design and estimation of the machine structures under irregular loading conditions.