• Journal of the Korean Solar Energy Society
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• v.33 no.1
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• pp.89-95
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• 2013

A DBLP(Double blind light pipe) daylight system can be installed at a building exterior wall or roof to replace artificial light during the day time. This system was consisted of a double blind light collector, a mirror duct type light transformer and a prism light pipe distributor. The double blinds were used to track the sun's altitude and azimuth movements to collect the sunlight throughout the day. The sunlight collected by the light collector was reflected on the first mirror and the second mirror and sent to the light pipe through the light transformer. The transformer was designed to deliver the sunlight into the light pipe efficiently. The light distributor plays a role in diffusing the sunlight coming in through the light collector to be used for indoor lighting. In this paper, a DBLP system has been designed, installed and tested at a KIER daylighting twin test cell. The DBLP daylighting system was applied to the experimental test cell which has an indoor area of 2.0 m wide ${\times}$ 2.4 m height ${\times}$ 3.8 m length. The experiment was conducted from January 30 to February 27, 2012, under clear skies and partially cloudy skies. Data was collected from 10:00 am to 16:00 pm every 2 minute and the average was calculated for every 30 minute of the data collection to obtain the system efficiency. The results indicated that the DBLP system efficiency was evaluated as 11.67%. The DBLP system indoor illumination energy reduction was predicted as 0.822 kWh/day. This could replace 4 sets of a 32W fluorescent lamp operating 6.4 hours per a day.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.127-131
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• 1997

Objective : To evaluate the clinical efficacy of adjuvant sertraline treatment in chronic schizophrenic patients, we carried out a double-blind, placebo controlled study. Method : Thirty six inpatients who fulfilled DSM-III-R criteria for chronic schizophrenia were randomly assigned to sertraline and placebo groups in a double-blinded fashion. A history of at least 2 years of illness and at least six months of hospitalization were prerequisities for inclusion in the study. Patients were received sertraline 50mg or placebo for 8 weeks in addition to their routine haloperidol regimen. Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression(CGI), Simpson-Angus Scale(S-A) were evaluated at 5 points ; baseline, 2, 4, 6, and 8 weeks of treatment. Results : The groups were controlled for age, gender, and length of illness. There were no significant differences in three PANSS factros(positive, negative, general), CGI, and S-A scale scores at any between sertaline and placebo treatment. Conclusion : This placebo controlled study showed no significant effects of sertraline on negative and positive symptoms in chronic schizophrenic patients.

• Steel and Composite Structures
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• v.38 no.5
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• pp.547-562
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• 2021

This paper aims to explore the mechanical behavior and moment-rotation model of blind bolted joints between concrete-filled double skin steel tubular columns and steel-concrete composite beams. For this type of joint, the inner tube and sandwiched concrete were additionally identified as basic components compared with CFST blind bolted joint. A modified moment-rotation model for this type of connection was developed, of which the compatibility condition and mechanical equilibrium were employed to determine the internal forces of basic components and neutral axis. Following this, load transfer mechanism among the inner tube, sandwiched concrete and outer tube was discussed to assert the action area of the components. Subsequently, assembly processes of basic coefficients in terms of their stiffness and resistances based on the component method by simplifying them as assemblages of springs in series or in parallel. Finally, an experimental investigation on four substructure joints with CFDST columns for validation purposes was carried out to capture the connection details. The predicted results derived from the mechanical models coincided well with the experimental results. It is demonstrated that the proposed mechanical model is capable of evaluating the complete moment-rotation relationships of blind bolted CFDST column composite connections.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.2
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• pp.171-183
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• 1995

Generally, among many kinds of shading devices such as venetian blind, sunscreen, louver and curtain, venetian blind is using widely because the mechanism is so simple and easy to use solar insolation by controlling the slat angle. Analysis of time dependent heat transfer through the window with venetian blind is very important in order to use it effectivly. Therefore, in this study, theoretical thermal analysis method was developed to analyze time dependent heat transfer through a double pane window with and without venetian blind, and was made one module of TRNSYS(A Transient Simulation Program)program. By this way, it was analyzed that how much the variation of slat angle, slat colour and slat absorptivity of venetian blind would be affected on the heating and cooling load of building, and also which colour and angle of slat was optimal for the heating and cooling load of building.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.799-804
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• 2011

The LFLP (Linear Fresnel Light Pipe) system uses a linear Fresnel lens to follow the sun and concentrates the parallel sunlight into a line. A LFLP daylighting system has been developed and updated to a DBLP (Double Blind Light Pipe) daylighting system to improve the overall system efficiency in the morning and afternoon. The new design consists of a double-blind style with a cone-shaped light transformer. The blinds are used to collect the sun's altitude and azimuth movements through the day. Behind the two sets of blinds is the light transformer, which is based on a parabolic-shaped light concentrator. The light transformer is designed to efficiently deliver light within a thirty-degree radial spread so that the light pipe can internally reflect the light. The results of scale-model tests are encouraging, and the efficiency is three times higher than that of the previous LFLP system.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.1-9
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• 2010

Apartment balcony has been remodeled since the government permitted remodeling in January 2006.But extended balcony has great impact on building heat gain and loss. Therefore It has problems such as increase of heating and cooling energy. So $\underline{t}echnical$ solutions about window solar gain in summer is an urgent matter. The Purpose of this study is to evaluate energy performance of a blind in a double-skin facade in residential buildings by using EnergyPlus program. The results show that slat angles of $90^{\circ}$ is best in energy performance if we do not consider daylight. Poorly daylighted living room needs electric light and it also causes high cooling load. On the other hand, the results show that the application of blinds controlled automatically is best for energy performance when we consider daylight. Blind slat angles of $50\sim60^{\circ}$ have best performance when blinds are controlled in this angle throughout the day on a clear day in August. Blind slat angles of $0\sim30^{\circ}$ have best performance when blinds $\underline{are\;controlled}$ in this angle throughout the day on a cloudy day (more than 7 of total sky cover) in August.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.979-986
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• 2018

This paper deals with acoustic echo cancellation using blind signal separation method. This method does not degrade the echo cancellation performance even during double-talk. In the closed echo environment, the mixing model of acoustic signals is multi-channel, so the convolutive blind signal separation method is applied and the mixing coefficients are calculated by using the feedback model without directly calculating the separation coefficients for signal separation. The coefficient update is performed by iterative calculations based on the second-order statistical properties, thus estimates the near-end speech. A number of simulations have been performed to verify the performance of the proposed blind signal separation method. The simulation results show that the acoustic echo canceller using this method operates safely regardless of the presence of double-talk, and the PESQ is improved by 0.6 point compared with the general adaptive FIR filter structure.

• The Journal of the Acoustical Society of Korea
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• v.27 no.1E
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• pp.17-24
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• 2008

Blind speech separation (BSS) is well-known as a powerful technique for speech enhancement in many real world environments. In this paper, we propose a new application of BSS - acoustic echo cancellation (AEC) in a car environment. For this purpose, we develop a block-online BSS algorithm which provides robust separation than a batch version in changing environments with moving speakers. Simulation results using real world recordings show that the block-online BSS algorithm is very robust to speaker movement. When combined with AEC, simulation results using real audio recording in a car confirm the expectation that BSS improves double talk detection and echo suppression.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.40.1-40.5
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• 2020

Background: Hyaluronic acid (HA) is well known to exert an anti-inflammatory effect during oral wound healing and is commonly applied after tooth extraction. However, no double-blind randomized controlled study comparing two hyaluronate mouthwash products has been conducted so far. The aim of this study was to comparatively analyze the efficacy of Mucobarrier^® and Aloclair^® in terms of clinical symptoms. Results: A total of 112 patients were randomly assigned to assess the degree of discomfort, pain reduction, redness, burning sensation, and swelling between two groups on the day of surgery and 7 days later in a double blind test, with a total 56 Aloclair patients and 56 Mucobarrier patients. There was no statistically significant difference in the overall discomfort, degree of pain reduction, redness, burning sensation, and swelling between the Mucobarrier and Aloclair groups. Conclusion: The local application of hyaluronic acid mouth wash after wisdom tooth extraction is beneficial in reducing overall discomfort and pain reduction, and the clinical utility of Mucobarrier^® is no different from Aloclair^®. Trial registration: Institutional Review Board of Yonsei University College of Dentistry, 2-2018-0036. Registered 10 September 2018-prospectively registered, https://eirb.yuhs.ac/

• Journal of the Korean Solar Energy Society
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• v.25 no.1
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• pp.57-64
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• 2005

The present society have been polluted the earth environment by the rapid industrial growth. So, the meaning of sustainable development is doing more important. Therefore the technology skills of sustainable architecture techniques have been studied many-side of energy as like energy saving and substitutive energy. But, See the studies until now, there have been just one system either energy saving or substitutive energy. So, the paper studies about energy saving system with substitutive energy system(the double-skin facade system with PV modules) and presents the performance of system through the analysis of reduction of the energy load, the solar radiation on the slope angle of PV module, the blind effect in system.