• Journal of Korean Society for Quality Management
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• v.46 no.1
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• pp.169-188
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• 2018

Purpose: The purpose of this study is to analyze low-temperature starting performance of the light attacker and to search and improve the aircraft system including battery and Battery Charge and Control Unit(BCCU). Methods: In order to improve the starting up performance of the light attacker at low-temp, various deficiency cause were derived and analyzed using Fault Tree Analysis method. As a result, it was confirmed there were drawbacks in the charging and discharging mechanism of the battery. The inactivation of the battery's electrolyte at low-temp and the premature termination of the battery charge were the main cause. After long error and trial, we improved these problems by improving performance of battery and optimizing the charging algorithm of BCCU. Results: It was confirmed that the problems of starting up failures were solved through the combined performance test of the battery and BCCU, the ground test using the aircraft system and the operation test conducted by Korea Airforce operating unit for 3 months in winter. Conclusion: This study showed that the improvement of quality reliability was achieved and thus the start-up performance issue of the light attacker has been resolved at low temperature. And it is expected that the design methodologies of temperature-affected electrical system of aircraft will contribute to the development of the aircraft industry in the future.

• Tunnel and Underground Space
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• v.18 no.5
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• pp.366-374
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• 2008

Tunnelling under water table induces many geotechnical problems because of groundwater. In subsea tunneling, reduction of face stability can induce flooding in the vicinity of a fracture zone characterized by high permeability and high water pressure. In this study, the effects of high water pressure on the stability of a tunnel face in a limited zone with high permeability(hazardous zone) are analyzed. On the basis of the 'advance core' concept, the seepage force acting on a hypothetical cylinder ahead of a tunnel face is modeled. This study focuses on the hydraulic behavior of the ground ahead of the tunnel face by three-dimensional steady-state seepage analyses. The impact of the hazardous zone on the seepage force and stability of the tunnel face are simulated and analyzed. In light of the analysis results, it is estimated that the distance from the tunnel face to the exterior boundary limit, which the seepage force significantly affects the stability of the tunnel face, of a hypothetical cylinder is approximately 5 times the tunnel radii. Despite the restrictive assumptions of this study, the results are highly indicative regarding the risks of hazardous zones.

• Korean Journal of Logic
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• v.17 no.1
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• pp.33-70
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• 2014

We still do not know against what histocial/philosophical background and motivation was Tarski's definition of logical consequence introduced, even if it has had such a strong influence. In view of the centrality of the notion of logical consequence in logic and philosophy of logic, it is rather shocking. There must be various intertwined reasons to blame for this uncomfortable situation. There has been remarkable progress achieved recently on the history of analytic philosophy and modern logic. In view of the recent developments of the controversies involved, however, we will have to wait years to resolve all this uneasiness. In this gloomy situation, Douglas Patterson's recent study of Tarski's philosophy of language and logic seems to have the potential to turn out to be a ground breaking achievement. [Patterson (2012)] This article aims at reporting the state-of-the-art in this problem area, and fathoming the future directions of research by examining critically some unclear components of Patterson's study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.535-544
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• 2009

Signals from the Global Positioning System(GPS) satellite are used to retrieve the integrated amount of water vapor or the precipitable water vapor(PWV) along the path between a transmitting satellite and ground-based receiver. In order to retrieve the PWV from GPS signal delay in the troposphere, the actual zenith wet delay, which can be derived by extracting the zenith total delay and subtracting the actual zenith hydrostatic delay computed using surface pressure observing, will be needed. Since it has been not co-located between GPS permanent station and automated weather station, the air-pressure on the mean sea level has been used to determine the actual zenith hydrostatic delay. The directly use of this air-pressure has been caused the dilution of precision on GPS PWV retrieval. In this study, Korean reverse sea level correction method of air-pressure was suggested for the improving of GPS PWV retrieval capability and the accuracy of water vapor estimated by GPS was evaluated through a comparison with radiosonde PWV.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.119-124
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• 2014

Blind adaptive systems based on the Euclidean distance (ED) between the distribution function of the output samples and that of a set of random symbols generated at the receiver matching with the distribution function of the transmitted symbol points estimate the ED at each iteration time to examine its convergence state or its minimum ED value. The problem is that this ED estimation obtained by block?data processing requires a heavy calculation burden. In this paper, a recursive ED estimation method is proposed that reduces the computational complexity by way of utilizing the relationship between the current and previous states of the datablock. The relationship provides a ground that the currently estimated ED value can be used for the estimation of the next ED without the need for processing the whole new data block. From the simulation results the proposed recursive ED estimation shows the same estimation values as that of the conventional method, and in the aspect of computational burden, the proposed method requires only O(N) at each iteration time while the conventional block?processing method does $O(N^2)$.

• Smart Media Journal
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• v.9 no.2
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• pp.22-32
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• 2020

The hippocampal volume atrophy is known to be linked with neuro-degenerative disorders and it is also one of the most important early biomarkers for Alzheimer's disease detection. The measurements of hippocampal pure volumes from Magnetic Resonance Imaging (MRI) is a crucial task and state-of-the-art methods require a large amount of time. In addition, the structural brain development is investigated using MRI data, where brain morphometry (e.g. cortical thickness, volume, surface area etc.) study is one of the significant parts of the analysis. In this study, we have proposed a patch-based ensemble model of 3-D convolutional neural network (CNN) to measure the hippocampal pure volume from MRI data. The 3-D patches were extracted from the volumetric MRI scans to train the proposed 3-D CNN models. The trained models are used to construct the ensemble 3-D CNN model and the aggregated model predicts the pure volume in one-step in the test phase. Our approach takes only 5 seconds to estimate the volumes from an MRI scan. The average errors for the proposed ensemble 3-D CNN model are 11.7±8.8 (error%±STD) and 12.5±12.8 (error%±STD) for the left and right hippocampi of 65 test MRI scans, respectively. The quantitative study on the predicted volumes over the ground truth volumes shows that the proposed approach can be used as a proxy.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.1
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• pp.40-45
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• 2016

In accordance with the digital broadcast data converted, the number of the service provider, and content channel for interaction with the viewer has increased exponentially. Electronic program guide in such a multi-channel time(Electronic Program Guide, EPG) is an essential requirement, and also from day to day EPG generation technique according to the user's requirements. But the current situation is getting EPG to viewers outside for reasons such as absence, lack of accurate information, organizing techniques utilized lack of standard systems. In this article, we describe the State and EPG solution to the problem of these terrestrial stations. This, the EPG information and the actual broadcast time of the terrestrial channel 6 using a ground wave receiving method for a direct comparison was studied the problems and the average error of the current start. Also this research perform to enhance accuracy of EPG information.

• Geotechnical Engineering
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• v.9 no.2
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• pp.15-26
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• 1993

Frost heave on foundation(or ice jacking) is defined that foundation is uplifted by heav- ing force exerted around foundation from freezing of soils. This phenominon is often occurred in the light -weight structure e.g, small building, electro - telegraph pole, street light, pipe line, budge and reference point of survey. Frost heave is the most important factor in design of foundation of structure and the key issue in understanding mechanism of foundation in permafrost area. In this study is reviewed the state of the art on the analysis method of frost heave in USSR and is suggested the design method of benchmark pile. On the basis of above results, this study suggests a design chart able to do esign simply the benchmark pile in Yakutsk region.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.21-27
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• 2020

Completed in September 1796, Suwon Hwaseong Fortress is a defense facility with 49 facilities spanning 5,744m. During the Japanese occupation and the Korean War, many buildings and walls were damaged, and in 1975, it was restored to its current state through the restoration and restoration project in Suwon. Six of the entire facilities have not been restored by urbanization, of which the restoration of water spaces, including ditches buried in the ground, could be used as a place of rest and viewing for visitors. Tourists visiting Suwon Hwaseong, are satisfied with exploring the historic sites, but feel insufficient for enjoying the natural scenery around the castle. The best way to create a natural landscape in Suwon Hwaseong, where urbanization has been developed, is to create a water space to make you feel the traditional garden. Therefore, the location, shape, and functions of the unrestored water space of Hwaseong Fortress were analyzed through the analysis of 『Hwaseong Seongyeog Uigwe』 and 『Hwaseong Full Map』. The purpose of this study is to derive the traditional landscaping method by analyzing the characteristics of water space.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.226-252
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• 2002

The results of a literature study about the comparison of Oriental-Occidental medicine on the Atopic dennatitis were as follows. 1. In Oriental medicine, Atopic dermatitis belongs to the category of the Naesun(내선), Taeryumchang(胎斂瘡), Eczema(濕疹), Chimumchang(浸淫瘡). In Occidental medicine, the other names of Atopic dermatitis are allergic eczema, IgE dermatitis, flexual eczema etc. 2. In Oriental medicine, the definition of atopic dermatitis includes chang(瘡), sun(선), and pung(風). Occidental medicine, is one of the intrinsic eczema classifications. In fact eczema term circumscribes dermatitis in atopic patients. 3. In Oriental medicine, the etiology and pathogenesis of Atopic dermatitis arose from the state of cogenital defect(稟賦不足), internal accumulation of damp and heat(濕熱內蘊) at first, and then invaded pathogenic wind, damp, heat factors again, and combined endo-exoteric pathogenic factors. So it appears in skin. In Occidental medicine, the etiology and pathogenesis of Atopic dermatitis approaches in genetic, allergic and immunologic, pharmacophysioloic aspects. It is only a hypothesis but there is no known facts about radical aetiology. 4. In Oriental medicine, differentiation of syndromes classifies manifestation aspects, etiology and pathogenesis, and invasion period. In Occidental medicine, it divides into an invasion period, and clinical aspect etc. 5. In Oriental medicine, Internal theraphys of Atopic dermatitis are decoction of ingredients(湯劑), pills(丸), and tablet(片). So, it prescribes as treatments on the ground of differentition of syndrome. In Occidental medicine, there is no radical therapy because Atopic dispositions don't change. But steroid, antihistamine as symptomatic tre atments are generally used in Occidental medicine. 6. In Oriental medicine, external therapies are wet dressings(濕敷), lotion(洗劑), powder(散劑), adhesive plasters(膏劑), oil(油劑), smoking(烟薰法), warm over fire therapy(熱烘療法), acupunture and moxibustion therapy(鍼灸療法).