• Journal of the Korean housing association
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• v.19 no.6
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• pp.157-166
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• 2008

Until 1960, the major housing type of rural area in Korea was traditional wooden frame building, which was made of natural materials. In the course of modernization and New Village Movement, most of traditional houses have been renovated focusing on changing roof material of rice straw into slate, keeping existing main wooden structure. And then from around 1980, by economical development the new houses have been constructed. On these three phases of traditional type, remodeling type and new construction type, the natural materials of housing facade as wood, soil, stone and plant changed into artificial materials as cement, chemical material and paint. At the same time the exterior color of housing also have been changed and varied. The purpose of this thesis is to find out the changing aspect of exterior color by comparing remodeled and new constructed housing with of traditional housing. The exterior color of one hundred and fifty seven houses were surveyed and the three color attributes of each part of facade, as roof, wall and window, were analyzed and compared. In case of traditional houses, 98.3% of color are concentrated on the warm color of Y and YR on HUE scale, and 88% of their color are low Chroma. And Value of their color has been varied and spreaded from low to high Value scale. From traditional types to remodeled and new constructed houses, the concentration ratio of warm color on Hue scale reduced from 98.3% to 68.7% and ratio of low Chroma was also changed from 88% to 73.2% and the ratio of low Value color reduced from 51.9% to 29.7%. The exterior color of houses in rural area varied on Hue, and the more saturated colors were used and they became brighter compared with color of traditional houses. It is expected that the results of this study can be used for basic data of exterior color planning and improvement into harmonized color with natural environment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.1
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• pp.74-81
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• 1998

It is not good joint that today's traffic control system that the course of traffic volume increase tendency is followed, in the traffic volume is approched into the time of my car. Accordingly when we analyzed the existing traffic signal control system, the traffic signal system is developed from the machine type that the motor was centered, to get up to date, to the intelligence electron signal control system. But yet, when we have a test and a A/S on the control circuit, the circuit that is designed to the center IC and ROM are complicated. Also, the time of pass lamp that the car line stream is going, can not extended automatically a time till the traffic volume is decreased to the same direction. This theme must be a real time intelligence control system that the time of pass lamp can extend aumatically. The circuit of sequence ladder diagram on the traffic signal control of a crossroads that is desinged, can be satisfied the complicated vehicle order. Therefore when the circuit is changed, the new developed system is economical with that dosen't needs any of components to require the circuit equipment, and the time is saved with needlessness of the circuit wiring again, and have a much trustworthy. The control method of pass signal lamp in the car line stream connecting among PLC and Relay and Temp Sensor, can be changed to hand operation and to semi-automation and to all-automation. New intelligence traffic signal system is composed with all-together system of T Sensor + Video Camera + IBM PC that is able to guiding the establishment of traffic order.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.95-100
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• 2010

LED (Light Emitting Diode) is 85% of the applied energy is converted into heat that is already well known. Lately, LED chips increasing the capacity as result delivered to increase the heat of the LED products and module that directly related to life span and degradation. Thus, in industry the high-power LED chip to control the heat generated during the course of the study and the existing aluminum, copper adhesives, and uses MLC (Metal clad laminate) structures using low-cost FR4 and copper CCL (Copper Clad Laminate) to reduce costs by changing to a study being carried out. In this study, using low-cost CCL Class, mounted 1W LED chip to analyze changes in the thermal resistance. In addition, heat dissipation in the CCL to facilitate a variety of thermal via design outside of the heat generated by the LED chip to control and facilitate the optimal structure of the heat dissipation is suggested.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.322-329
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• 2016

This study is about the method to control the quality of material used to repair leakage and crack of concrete structure and suggests the "Temperature Stability Test Method" as a follow-up study. In the result of performance evaluation for 45 samples of 15 types in 5 series, the temperature stability test showed different material changes including rolling down, volume change, and color change as they are frozen and melt repeatedly in the somewhat extreme conditions at low($-20^{\circ}C$) and high($60^{\circ}C$) temperatures, where 13 samples (approx. 29%) and 32 samples (approx. 71%) showed leakage, respectively, in the permeability test to evaluate leakage. This result shows the enough importance of setting the quality control criteria of leakage repair material currently used to maintain concrete structures considering the temperature conditions, and proves the applicability of the Temperature Stability Test Method as a standard test method to ensure long-term durability of concrete structure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.641-645
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• 2004

Crude chondroitin sulfates extracted from midduck tunics (Styela clava) and munggae tunics (Halocynthia roretzi) were examined in vivo in order to be utilized as a cosmetic material which was followed by an in vitro assay. Examinations, such as acute oral toxicity, skin sensitization, acute eye irritation, and primary skin irritation, were peformed with a variety of laboratory animals. Phototoxic and photosensitization tests were not conducted since all chondroitin sulfates failed to absorb U.V. light at the range of 280 to 420 nm. In acute dermal and eye irritation, both specific clinical signs and dead cases were not demonstrated during the test period, but crude chondroitin sulfates from midduck and munggae tunics, and standard chondroitin sulfate from bovine trachea were showed 2.5, 1 and 1.25 of acute ocular irritation index (A.O.I.), respectively. In the case of skin sensitization, crude chondroitin sulfate from midduck tunics exhibited neither specific clinical signs nor dead cases in the entire course of the examination. While in acute oral toxicity, crude chondroitin sulfates from both midduck and munggae tunics found neither specific clinical signs nor dead cases during the test, and LD50 was suspected to be over 2 g/kg. Based on this study, it was proven that crude chondroitin sulfates from either midduck or munggae tunics can be used safely as a cosmetic material.

• Korea Science and Art Forum
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• v.30
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• pp.251-261
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• 2017

Metal is a material that has exerted a lot of influence on the development of human cultures, and has closely connected with our life from the past to the present. Types of metal we have used from the prehistoric times are varied, and iron relics take the largest percentage of metal relics excavated in our country. The biggest threat to the existence of iron relics ranging from excavated relics to the ones that are transmitted is the process of corrosion, and physical removal has been used the most for removing corroded oxides. For details for removal of corrosion oxides, this thesis aimed to research on the chemical corrosion oxides remover that protects parent material of iron relics but treats corrosion oxides only. For safe and effective removal of corrosion oxides of iron relics, this study was conducted aiming at finding the possibility of and optimized composition for removal of iron relics corrosion oxides by manufacturing new acid, alkaline and neutral oxides removers and changing their composition variously, exploring the possibility by applying the agents to modern relics. The results of this study are as follows: First, the acid solution removed only some part of corrosive substance oxidized on the surface of metal specimen. Second, the application of each of alkaline and neutral solution resulted in remaining black-colored corrosive substance, but it was removed when the quantity of the solution and the duration of application are increased. Third, All the three solutions did not cause any damage to parent material in the course of application, and showed the result that they are capable of removing unstable oxide layer while protecting parent material and stable corrosive layer as the solutions would be able to deal with situation by a relic only through the control of concentration of solution and duration of application.

• Geotechnical Engineering
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• v.5 no.3
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• pp.19-28
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• 1989

This study has been carried out as a fundamental course for the analysis of the constitutive- equation for the materials like sands being hardened during Ehear. For this aim, experimentall tests with variable stress paths for the concrete material are performed using the cubical multi- axial test in which the three principle stresses are arbitrarily controlled. Stress-strain behaviors. and strength characteristics are suggested in octahedral planes. Various tests such as HC, CTC, . TC, 55 are performed. The main results summarized are as follows; 1. The order of strength from the largest to the smallest is CTC, TC, SS, and TE test. 2. The octahedral Ehear strength of concrete specimens is dependent upon the stress path(8) 3. There is a direct relation between strength and confining pressure. 4. The ultimate envelopes in the octahedral planes are non-circular-cone shaped. 5. Any ultimate criteria used to predict the strength behavior of concrete must include thin effect of the tensile stresses.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11c
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• pp.105-116
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• 1999

The Inchon International Airport site was formed by reclaimed soil from the sea. The average thickness of soft soil Is about 5 m and most of soft soils are normally consolidated or slightly over consolidated. There are many box culverts which are being constructed under the runways in the airfield. Sometimes, differential settlement can be occurred in the adjacent of box culvert or underground structures at the top layer of runway Soil compaction at very near to the structure is not easy all the time. Thus, one layer of geogrid was placed at the bottom of lean concrete layer for the concrete paved runway and at the middle of cement stabilized sub-base course layer for the asphalt paved runway. The length of geogrid reinforcement is 5m from the end of box culvert for both sides. The extended length of geogrid was 2m from the end of backfill soil in the box culvert. The tensile strength tests of geogrid were conducted for make sure the chemical compatibility with cement treated sub-base material. The location of geogrid placement for the concrete paved runway was evaluated. The construction damage to the geogrid could be occurred. Because the cement treated sub-base layer or lean concrete was spread by the finisher. The magnitude of tensile strength reduction was 1.16%~1.90% due to the construction damage and the ultimate tensile strength is maintained with the specification required. Total area of geogrid placement in this project is about 50,000 $m^2$.

• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.337-341
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• 2012

Mechanochemical processing (MCP) involves several high-energy collisions of powder particles with the milling media and results in the increased reactivity/sinterability of powder. The present paper shows results of mechanochemical processing (MCP) of silicon nitride powder mixture with the relevant sintering additives. The effects of MCP were studied by structural changes of powder particles themselves as well as by the resulting sintering/densification ability. It has been found that MCP significantly enhances reactivity and sinterability of the resultant material: silicon nitride ceramics could be pressureless sintered at $1500^{\circ}C$. Nevertheless, a degree of a silicon nitride crystal lattice and powder particle destruction (amorphization) as detected by XRD studies, is limited by the specific threshold. If that value is crossed then particle's surface damage effects are prevailing thus severe evaporation overdominates mass transport at elevated temperature. It is discussed that the cross-solid interaction between particles of various chemical composition, triggered by many different factors during mechanochemical processing, including a short-range diffusion in silicon nitride particles after collisions with other types of particles plays more important role in enhanced reactivity of tested compositions than amorphization of the crystal lattice itself. Controlled deagglomeration of $Si_3N_4$ particles during the course of high-energy milling was also considered.

• Plant Journal
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• v.8 no.1
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• pp.50-59
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• 2012

The current dual-watchdog estimation system has individually calculated the construction, the engineering and the procurement cost. The dual-watchdog estimation system is inefficient and prolonged estimation period because of the lack of the interoperability and the difference of material unit cost and construction unit cost. In order to resolve this problem, new estimation software was developed. The estimation software is developed by making up for the weak points in existing estimation method. The cost data with the same standard is the key point. And this software enhanced accuracy and speed of the data search in stylized estimation standard. A summary of the construction, the engineering and the procurement cost was generated in this estimation software. The unit rate about the labor cost, equipment and expense through a sheet was handled. The developed estimation software has five categories on engineering cost, procurement cost, construction cost and subcontractor management sheet. In this study, the estimation software to supplement the faults of the existing estimation method was developed. And estimation software on petrochemical projects increases an efficiency of the estimation work.