• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2548-2553
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• 2008

Prediction of the rotor blade performance is important for determining design factors such as weight and size in development of a small-scale helicopter. Generally, prediction of helicopter performance means the estimation of the power required for a given flight condition. However, due to lack of test data and analyzed results for small-scale rotor blade operated at low Reynolds numbers ($Re{\approx}10^5$), this is not an easy task. As an initial research, this work performs a modeling of a single rotor configuration with FLIGHTLAB and a experimental research with rotor test bed. In this process, we performed small-scale isolated single rotor by experimental and numerical method and achieved good agreement of the hover performance on the test data and simulation results.

• Water for future
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• v.29 no.3
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• pp.129-142
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• 1996

This study investigates the magnitude of errors that can be expected in integrating sediment concentration in a vertical, basede on a single-point measurement, because of errors in input data. Potential error sources, including sampler location, water surface elevation, bed elevation, fall velocity, $\beta$ value, and $\kappa$ value were comparatively examined using data from a special study on the Rio Grande Conveyance channel in New Mexico. It is concluded that simple forms of equations for the vertical distribution of velocity and sediment concentration based on a single-point field sample of suspended sediment. The most uncertain point in the computation is related to the Rouse number z in the equation for the vertical concentration distribution of suspended sediment.

• Journal of the Korean housing association
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• v.14 no.4
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• pp.39-48
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• 2003

The purpose of this study was to analyze the changes of floor plans in the entry and transfer spaces of single detached houses. The sample size was 185 households in Chungju, Jechon and Wonju Which are small cities in the central region of Korea. The results of the study are as follows: Firstly, the approach and transfer spaces show various changes and those are important factors which symbolize the housing plane typology transformations of the research areas. Secondly, the approach direction to the indoor space was more adopted a front approach in 1960's and 1970's, it is a side approach in 1980's, and a back side approach in 1990's. Thirdly, as the stage of the transfer space increased, the detached house planes have been changing to the direction, the depth of space comes to be deep, spatial function to be fixed, and privacy of bed rooms to be increased.

• Polymer(Korea)
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• v.29 no.6
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• pp.549-556
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• 2005

Effects of the dimensionless variables on the heat transport phenomena in the extrusion process of a single screw extruder have been studied numerically. Based on the understanding of the solids conveying related to the geometrical structure and characteristics of the screw, the heat balance equation for the solids conveying zone was established and normalized. The finite volume method and power-law scheme were applied to derive a discretized equation and the equation was solved using the alternating direction iterative method with relaxation. Effects of the dimensionless parameters, Biot and Peclet numbers, that define the heat transfer characteristics of the solids conveying zone have been investigated with respect to the temperature of the feeding zone and the length of the solids conveying zone. As the Biot number is increased, the heat loss by cooling dominates to decrease the temperature of the barrel but it has little effects on the temperature of the solids bed and the length of the solids conveying zone. On the other hand, if the Peclet number is increased, the convection term dominates to decrease the temperature of the solids bed and it results in an increase in the length of the solids conveying zone.

• The Journal of Korean Academy of Sensory Integration
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• v.10 no.2
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• pp.23-32
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• 2012

Objective : The aim of the present single subject research was to identify the effect of sensory diet based on proprioception on toddler's sleep pattern and the continuance of the effect. Methods : The sensory diet based on proprioception consisted of 14 session was provided to a 13 months old girl for 2 weeks. The time taken to fall asleep, amount of sleep, bed time and severity of behavior before sleep were recorded by her mother who was taken the education about observation. Results : After the sensory diet, the child present change of time taken to fall asleep, amount of sleep, bed time and severity of behavior before sleep, and the effect on time taken to fall asleep, continued temporally. Conclusion : The sensory diet based on proprioception was related to stabilize the sleep pattern of a toddler, and the effect of the sensory diet continued temporally after the sensory diet. For future research, more subjects and methodical measure are need to generalize the result of sensory diet based on proprioception affecting to toddler's sleep pattern.

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.45-56
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• 2015

The main purpose of this investigation is to make up for the limitations of parcel addressing and to seek the application plan of cadastral triangulation point to effective installation of national index numbers. The test-bed has been constructed at the mountainous area located in Nowon-gu, seven cadastral triangulation points within the test-bed was directly applied to this investigation. Each points have been firstly converted from a plane rectangular coordinates to a single plane rectangular coordinates (UTM-K). To verify positioning results achieved from these points, a single plane rectangular coordinates through the Network-RTK was considered. With regards to verification result, maximum coordinate shift was revealed by 6 cm, this level of difference can be satisfied to Article 7, paragraph 2 "the regulation for National Index Number". This means that coordinate transformation applied with cadastral triangulation points can achieve the sastisfied result without local surveying. And also, remarkable effects have been created in terms of financial effectiveness and safe preservation of cadastral triangulation points due to the omission of local surveying.

• Fashion & Textile Research Journal
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• v.4 no.3
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• pp.248-253
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• 2002

The purpose of this study was to improve consumer sleeping life in quality and to suggest producers meet new consumer needs and demands, by examining the nationwide use of bedding, analyzing consumer sleeping life by category and age group, comparing the results with the findings of the nationwide studies by Sung Su-kwang (1992) and Lee Song ja (1995), and identifying the major trend of consumer sleeping life. Results and Discussion The findings of this study were as below: 1. The General Characteristics of the Subjects : Most of the housewives investigated were in their 30s and 40s, with 41.7% and 50.8% respectively. 2. Bedroom : When it comes to bedroom style, 47.8% put beds in their rooms with the Korean under-floor heating system, and 45.4% didn't place beds in their rooms with the same heating system. 3. The Purchase of Bedding : 49.0%, approximately half the homemakers, bought their current bed-clothes at bedding shops, and just 3.2% made them on their own at home. 4. The Use of Bedclothes : In summer, yam (flax, ramie fabric) and a single-layer bed sheet (41.9%) were in use most, followed by a single-layer quilt (34.5%). 5. Bedding Management The most common frequency of bedding disinfection by sunning was once a month (29.4%), followed by once per two weeks (23.9%) and once a week (19.0%) in the order named.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.136-147
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• 2005

Leachate from landfill sites contains high organics, chloride and ammonium nitrogen in concentration which might be potentially major pollutants to surface and groundwater environment. Most of landfill leachate treatment plants in Korea consist of biological processes to remove BOD and nitrogen. However, the efficiencies of refractory organics removal, nitrification and denitrification have not met frequently the national effluent regulation of wastewater treatment facility, especially in winter season. Simultaneous removal of organics and nitrogen from leachate is strongly necessitated to meet the national regulation on effluents from leachate treatment facilities. The intermittently aerated biological activated carbon fluidized bed(IABACFB) process was applied to treat real landfill leachates containing refractory organics and high concentration of ammonium nitrogen. The IABACFB reactor consisted of a single bed in which BAC fluidizing and an aerating column. The fluidized bed is intermittently aerated through the blower located at the aerating column. Experiments were performed to evaluate the applicability of Intermittently Aerated BACFB for simultaneous removal of refractory organic carbon and ammonium nitrogen of leachate. Organics and ammonia nitrogen($NH{_4}{^+}-N$)are oxidized during the aerobic stage, and nitrite-nitrate nitrogen($NO{_x}{^-}-N$) are removed to nitrogen gas through denitrification reaction during anoxic state. The IABACFB reactor condition reached a steady state within 40 days since the reactors had been operated. The blowing mode of 60 min.-On/60 min.-OFF is more compatible to remove TOC and ($NH{_4}{^+}-N$) operated. The blowing mode of 60 min.-On/60 min.-OFF is more compatible to remove TOC and ($NH{_4}{^+}-N$) simultaneously than the mode of 30 min.-On/90 min.-OFF. The average removal efficiencies of TOC, the refractory organic carbon, and the average efficiencies of nitrification and denitrification were 90%, 75%, 80%, 95%, respectively.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.2
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• pp.55-62
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• 2012

In this paper we propose a control system to preserve the interior angle between back section and upper leg section to be larger than 90 degrees using a single limit switch. To design the control system we analyze the kinematics of actuation mechanisms for the back section and the upper leg section, and find out an optimal solution for the controller design. Using a prototype control system we perform experiments to test the controller performance, and show that the interior angle between the back section and the upper leg section is always preserved larger than 90 degree. From the experimental results, we show the proposed control system is feasible to keep the body posture stability.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.4
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• pp.35-44
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• 1999

In this study, it was attempted to remove nitrate and carbon in a single-stage reactor using acetate as substrate. Hybrid type upflow sludge baffled filter reactor was adopted using anaerobic sludge. Sludge bed in the bottom of reactor was intended to remove carbon and nitrate by denitrification and methanogenesis. And floating media in the upper part of reactor were intended to remove remaining carbon which was not removed due to the inhibition of nitrogen oxide on methane producing bacteria. The reactor removed over 96% of COD and most of nitrate with volumetric loading rate of $4.0kgCOD/m^3{\cdot}day$, hydraulic retention time of 24hr, 4,000mgCOD/L, and $266mgNO_3-N/L$. Nitrate in anaerobic sludge was converted to nitrogen gas(denitrification) or ammonia (ammonification) according to pH of influent, COD removal efficiency was easily affected by the change of volumetric loading rates and nitrate concentration. And when influent pH was about 4.7, most nitrate changed to ammonia while when influent pH was about 6.8~7.0, most nitrate denitrified independent of $COD/NO_3-N$ ratio. Most granules were gray and a few were black. In gray-colored granule, black inner side was covered with gray substance and SEM illustrated Methanoccoci type microorganisms which were compact spherical shape. Anaerobic filter removed residual COD effectively which was left in sludge bed due to the inhibition of nitrogen oxide.