• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.539-547
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• 2019

Recently, the international community signed a climate change agreement to prevent global warming. Yet currently, the fossil fuels have been widely used in to supply building energy for cooling and heating. The Green Building certification (G-SEED), an energy efficiency rating for new or existing buildings requires that buildings meet certain conditions. Insulation is used as a building material to reduce the energy supply to buildings and to improve the thermal insulation, and it accounts for more than 90% of the total heat resistance provided by the building surface components that meet the energy-saving design standards of new buildings. In this investigation, a performance evaluation study was conducted through an experimental study by directly extracting the foam polystyrene insulation on-site during the remodeling of a building that was in the range of 22~38 years old. Through tests, it was found that the thermal conductivity of the extrusion method insulation (XPS) was reduced by 48% and the compressive strength of XPS decreased by 36% compared to KS M 3808, which is the initial quality standard. For bead method insulation (EPS) with a thickness of 50mm, the thermal conductivity, the compressive strength, and flexural failure load were similar to the initial quality standard. Therefore, in the calculation of the primary energy requirement per unit area per year, the performance of bead method insulation can be estimated simply by considering the thickness of the insulation, while a correction factor that considers its performance deterioration should be applied when extrusion method insulation is used.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.389-395
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• 2017

A study was carried out to improve the field implementation of asphalt surface reinforcement method which is a preventive maintenance. Mean Texture Depth (MTD) was measured to quantify the surface condition and used to determine the optimum application rate. Determining the application rate using MTD can reduce the material loss from 30% to 15%. In order to reduce the curing time to 30 minutes, the heat capacity of $317kcal/m^2$ is required. Therefore, the design capacity of the heating curing device requires more than 380,000 kcal/hr. The asphalt surface reinforcement method is preferably applied at a time when slight cracking occurs before the permanent deformation becomes serious. Through the analysis of the pavement survey data, it was decided to apply the surface reinforcement method at the crack rate of 3~4%. Heating the surface reinforcement agent to $50^{\circ}C$ improves workability and ensures sufficient penetration depth even at a crack width of 1 mm. The results will be utilized as basic data for the development of automated construction equipment for efficiency improvement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.691-698
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• 2012

The joining of aluminum and HSS (high-strength steel) by the conventional clinching process is limited by the low formability of HSS. Defects in the clinching joint, such as necking of the upper sheet, cracks, and lack of interlocking, are produced by the different ductility properties of HSS and aluminum. In this study, we propose the hole clinching process for joining Al6061 and SPFC440, in which deformation of SPFC440 is avoided by drilling a hole in the SPFC440. The dimensions of the interlocking in the hole-clinched joint necessary to provide the required joint strength were determined. Based on the volume constant of the hole clinching process, the shapes of the tools were designed by finite element (FE)-analysis. A hole clinching experiment was performed to verify the proposed process. A cross-section of the joint showed good agreement with the results of the FE-analysis. The lap shear strength was found to be 2.56 kN, which is higher than required joint strength.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1265-1272
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• 2014

This study performed the progressive failure analysis of adhesive joints of a composite pressure vessel with a separated dome by using a cohesive zone model. In order to determine the input parameters of a cohesive element for numerical analysis, the interlaminar fracture toughness values in modes I and II and in the mixed mode for the adhesive joints of the composite pressure vessel were obtained by a material test. All specimens were manufactured by the filament winding method. A mechanical test was performed on adhesively bonded double-lap joints to determine the shear strength of the adhesive joints and verify the reliability of the cohesive zone model for progressive failure analysis. The test results showed that the shear strength of the adhesive joints was 32MPa; the experiment and analysis results had an error of about 4.4%, indicating their relatively good agreement. The progressive failure analysis of a composite pressure vessel with an adhesively bonded dome performed using the cohesive zone model showed that only 5.8% of the total adhesive length was debonded and this debonded length did not affect the structural integrity of the vessel.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.37-44
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• 2008

The multi-layer PET film of ITO/ATO was prepared by a wet coating method to obtain the transparent film with a high conductance at low cost. ITO nano-particles were synthesized by a SAS method at 15 MPa and $50^{\circ}C$, where optimized rate of In/Sn was 65. Average diameter and resistivity of ITO obtained from SAS are $15{\pm}2nm$ and $4{\times}10^4{\Omega}{\cdot}cm$. Coating solution was prepared at pH 10. Roughness (Ra), resistivity, and transmissivity of ATO film on PET are 9 nm, $5.5{\times}10^6{\Omega}{\cdot}cm$, and 91%. The multi-layered film of ITO/ATO was obtained by solution including 0.1, 0.5, 1.0, and 2.0 ITO wt% on ATO layer. Roughness (Ra) of multi-layered film with 0.1, 0.5, 1.0, and 2.0 ITO wt% is 4, 10, 12, and 16 nm, respectively. Corresponding resistivity with an increasing ITO concentration is $3.7{\times}10^6$, $2.4{\times}10^6$, $8{\times}10^5$, and $2{\times}10^5{\Omega}{\cdot}cm$. Transmissivity of ITO/ATO film decreases as 89, 88, 86, and 82% with an increasing ITO concentration as 0.1, 0.5, 1.0, and 2.0 wt%.

• Information Systems Review
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• v.8 no.1
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• pp.1-24
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• 2006

Now, the Korean footwear industry needs the concrete enhancement of its competitive edge for regaining of its previous well known reputation. For this purpose, this study emphasizes the cooperation between the members through the supply chain of Korean footwear industry, as a c-SCM(Collaborative Supply Chain Management) by aid of information system. The key issue will be how well to coordinate operations flow not only through internal process stages, but also through entire external supply chain stages. In other words, the target goal must be the system optimization through the entire supply chain beyond the local optimization of internal supply chain process. We, at first, analyze the traditional structure of supply chain in Korean footwear industry and find out critical problems, and then, we develop the collaborative information framework in conjunction with several collaborative process modules. The suggested collaborative production & supply planning system was designed for sharing information and it is based on ebXML(electronic business eXtensible Markup Language) framework. In this way, the enhancement of the efficiency and competitiveness can be expected through the synergy effect of coordination of information and material flow, the reduction of lead times, and production costs.

• Fire Science and Engineering
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• v.16 no.1
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• pp.18-23
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• 2002

Efficiency estimation of toxicity free resistance cable experiments were conducts to understand toxicity free fire ersistance polyolefin insulation material and smoke density characteristic and combustion gas corrosion analysis. A main cause of fire-growth and generating toxic gas when it burns, should be dealt with great care in life safety design. Similar patterned fire incidents such as, Inchon Live-Hof Pub Restaurant as, Sea-land Children Resort have proven that serious loss of lives were caused by hazardous gas generated fire resistance cable materials. In this paper, Referenced documents were ASTM E662 standard test method for specific Ds genalated by solid materials. The furnace control system shall maintain the required irradiance level under steady-state condition with the chamber door closed of 2.5$\pm40.04〔w/$\textrm{cm}^2$〕for 20 min. According to the results of the smoke density analysis of NFR-8 and FR-PVC the highest decomposition flaming smoke density range of NFR-8 and FR-PVC were 25.2 to 37.5 and 51.1 respectively. Nonflaming smoke density range of NFR-8 and FR-PVC were 100.4 to 112.2 and 126.5 to 398.8. Also, the fire gases was occurred carbon monoxide and decomposition than in polyolefin due to incomplete combustion of PVC which has high content of carbon in chemical compound.

• Journal of Biosystems Engineering
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• v.7 no.1
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• pp.17-32
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• 1982

The binders introduced in Korea were originally designed to be used for Japonica-type varieties which have relatively long stem and are highly resistant to shattering. In order to use it for Tongil varieties which are short and easy to be shattered, mechanical modifications are necessary to reduce a grain loss incurred during binder operation. This study was intended to investigate analytically and experimentally the major sources of grain losses caused by three kinds of binders now introduced in Korea. Actual modification for each of three binders was done and experimentally compared to see if any improvement on grain loss was achieved. The results obtained in this study are summarized as follows; 1. It was required that the power transmission of binder should have a shifting mechanism so that velocities of pick-up and traveling units could be changed independently as desired according to the Japonica-type and Tongil varieties. In other words, the desired velocity of traveling unit should be obtained by shifting the transmission and the velocity of pick-up unit should be selected by reaping clutch according to the variety independent of the velocity of traveling unit as shown in Fig. 6. 2. To reduce grain loss it was desired that the moving parts of the pick-up unit should have the lowest possible velocities in harvesting Tongil varieties, unless the reduction of the speed be hindered the conveyance of the material. Based on the study, it was concluded that the velocities of pick-up unit be reduced by about 35% of those of the existing units. 3. It was found that the lug at the upper rotating section of pick-up case gave a severe impact on the ears of rice to increase grain loss. The optimum design of pick-up case to protect the ears from the protruding part of the lug was recommended by the result of analysis of the trajectory of the end-point of lug at the position. 4. It was proved analytically and experimentally that pick-up unit at the lower-rotating part was the other important source of grain loss in pick-up and divider assembly. In order to reduce a grain loss incurred by lugs at their lower-rotating section, it was suggested to improve it by (1) widening the space between right and left lower-rotating section, (2) shortening the length of lugs, (3) enlargement of the angle between the pick-up case and ground-level, and (4) attaching guard to right and left dividers so that the rotating lug could not give a high impact to the paddy hill. 5. Pick-up and divider assembly of the original binder of three models studied was modified according to the suggestions that were given by the preliminary study. Field test showed that the modified binders were able to reduce grain losses by about 0.4-0.7 percentage points compared to those without modification.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.467-474
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• 2010

Recently, Study of functional clothing for Vital sensing is focused on reducing artifact by human motions, in order to enhance the electrocardiogram(ECG) sensing accuracy. In this study, considering the factors for each element found from the analysis, a 3-lead electrode inside textile embroidered with silver yarn was developed, and draft designs off our types of vital-signal sensing garments, which are 'chest-belt typed' garment, 'cross-typed' garment 'x-typed' garment and 'curved x-typed' garment, were prepared. The draft designs were implemented on a sleeveless male shirt made of an elastic material so that the garment and the electrodes can remain closely attached along the contour of the human body, and the acquired data was sent to the main computer over a wireless network. In order to evaluate the effects caused by body movements and the ECG-sensing capability for each type in static and dynamic states, displacements were measured from one and two dimensional perspectives. ECG measurement evaluation was also performed for Signal-to-noise ratio(SNR) analysis. Applying the experimental results, the draft garment designs were modified and complemented to produce two types of modular approaches 'continuous-attached' and 'insertion-detached' for the ECG-sensing smart clothing.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.695-698
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• 2010

Purpose: Supernumerary nipple or polythelia is one of the developmental anomalies occurring at the embryonic stage and this anomaly usually arises from the milk line. While this atypical feature is determined during early developmental stage, it may not come out obviously or become troublesome until puberty or lactation. Moreover, sometimes it is confused with a pigmented nevus. Methods: Case 1, a 18-year-old woman with intramammary supernumerary breast consisted of another nipple with middle sized areola on the right lower breast was admitted for a $2.8{\times}3.1\;cm$-sized mass on the right breast which was starting appeared 1 year earlier. The preliminary cytological examination of the material obtained by needle aspiration biopsy from the mass was revealed by fibroadenoma with no malignant change. The patient had the surgical excision of the mass and accessory breast. Case 2, a 16 year-old woman admitted for intra-areolar polythelia of the left breast, even she doesn't have any family history of polythelia. Since she wanted surgical correction of her atypical nipple for aesthetic and psychological reasons, we reconstructed the areola using transposition flaps in an S-plasty design. Results: Case 1, the excised supernumerary nipple showed following histological features. In the superficial layer, an acanthotic and hyperpigmented epithelium with elongated rete ridges was found. In the dermis, there were follicles with hairs surrounded by hypertrophic sebaceous glands. In the deepest portion, abundant secretory glomerules and excretory ducts of apocrine gland type were observed. Case 2, follow-up visits 3 months after the procedure showed a satisfactory result with good shape and projection of the nipple. Conclusion: We report two cases of aberrant mammary tissue who underwent surgical correction, including complete breast (with nipple, areola, and glandular tissue) and intra-areolar polythelia according to the Kajava's classification, and the results were satisfactory.