• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.686-689
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• 2005

This study aims to analyzed the acoustics characteristics of Korean Traditional Houses in Chonnam Province varied with lay out and floor plane to reflect the way of control for environmental condition. These houses are surveyed the reverberation time and level difference between rooms of the main living room and other main floored room, master room and kitchen. As a result, the reverberation time of traditional rooms are below 0.6 second, and the sound insulation performance of Korean traditional door are mostly very low grade with D-15. The level difference between rooms are low grade not to meet minimum class except between main living room and master room away from main living building.

• Bulletin of the Korean Mathematical Society
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• v.58 no.6
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• pp.1315-1325
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• 2021

In this paper, we firstly prove some general inequalities for the Neumann eigenvalues for domains contained in a Euclidean n-space ℝⁿ. Using the general inequalities, we can derive some new Neumann eigenvalues estimates which include an upper bound for the (k + 1)^th eigenvalue and a new estimate for the gap of the consecutive eigenvalues. Moreover, we give sharp lower bound for the first eigenvalue of two kinds of eigenvalue problems of the biharmonic operator with Navier boundary condition on compact Riemannian manifolds with boundary and positive Ricci curvature.

• Computers and Concrete
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• v.19 no.1
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• pp.111-120
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• 2017

This study aimed to design the accelerated life testing (ALT) of concrete, which stimulating the special natural environment maximumly. Its evaluation indexes, such as dynamic elastic modulus, mass and ultrasonic velocity were measured, and the variation of relative mass and relative dynamic elastic modulus of concrete were studied. Meanwhile, the microanalysis method was used. Moreover, an exploratory application of the stochastic approach, the Weibull distribution and the lognormal distribution, were made to assess the durability of concrete structures. The results show that the ALT for simulating natural environment is more close to the service process of concrete structure under actual conditions; The relative dynamic elastic modulus can be used as the dominant durability evaluation parameters, because it is more sensitive to the environmental factors compared with the relative quality evaluation parameters; In the course of the concrete deterioration, the destruction of the salt freezing cycle is the dominant factor, supplemented by other factors; Both of those two stochastic approaches can be used to evaluate the reliability of concrete specimens under the condition of ALT; By comparison, The lognormal distribution method is better to describe the reliability process.

• Journal of the Korean Institute of Rural Architecture
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• v.7 no.1
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• pp.88-99
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• 2005

The purpose of this study is to minimize physical obstacles, to propose how we can improve them, and to get the basic information to establish the welfare policy for handicapped students in the university dormitory by studying and analyzing actual conditions of existing facilities and its improving transition which provide most important living accommodation to university students. To carry out this study, they have been surveyed 10 Universities in Korea as a case study which 1 university in Seoul & Kyunggi province, 2 universities in Chungchung province, 5 universities in Jeolla province and 2 universities in Kyungsang province. And they have been studied in relation to the law, theory of the architectural planning & design, and general consideration about handicapped people. As a result the checklist about the facilities was made. The term of survey was in August 2001 and in September 2004. It is concluded that most of universities which have been surveyed were equipped with good facilities for general students without regards for handicapped people at that time. As you can see the result of this research, the facilities of boarding house for handicapped people are very scanty in many universities. So they must be required facilities for handicapped people in the stage of architectural programming, the process of designing the dormitory facility.

• Journal of Mushroom
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• v.1 no.1
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• pp.21-27
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• 2003

The compost dextrose(CD) medium was selected a an optimum liquid culture media for Portobella(Agaricus brunescens). The optimal conditions for the mycelial growth of Agaricus brunescens were 25 and pH 7.0. Sucrose and soluble starch were favorable to mycelial growth. Malt extract and ammonium nitrate appeared to be more favorable than the other kinds of nitrogen source. The optimum C/N ratio as about 10.When the collected Portobella trains were compared with growth characteristics, KME 49007 appeared the highest of $44.6kg/3.3m^2$.

• Journal of the Korean Society of Food Culture
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• v.19 no.4
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• pp.460-467
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• 2004

Survey on the usage of commercial poggi Kimchi was run and consumer's acceptance test of the Kimchi in the various regions of Korea including Seoul(SE), Kyonggi Province(KG), Kangwon Province(KW), Kyungsang Province(KS), and Jeonla Province(JL) were investigated. Survey result of 34% of consumer showed that they eat Kimchi very much, and 19% answered they ate Wimchi whenever they had chance to eat. The most desired points of improvement in commercial poggi Kimchi were as following; Taste and degree of fermentation should be standardized. Order of preferences of minor ingredients of Kimchi were radish, hot pepper, welsh onion, and leek, respectively. Consumer acceptance test of KS sample group showed higher preference in whole color, salted condition, spicy hot flavor and crispness than the others. In whole color and pickled seafood properties, KG sample group showed significantly higher values than the others. In salty flavor, SE sample group showed lower preference than the others.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.97-100
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• 2006

The paper proposes a condition that should be satisfied when using the combination with different carrier phase observations to get the high precision deformation value. If the condition is satisfied, on the basis of DC algorithm, when the deformation is relatively large (0.7m)，high precision deformation value can be obtained.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3465-3479
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• 2017

Information-Centric Vehicular Ad Hoc Network (IC-VANET) is a promising network architecture for the future intelligent transport system. Video streaming applications over IC-VANET not only enrich infotainment services, but also provide the drivers and pedestrians real-time visual information to make proper decisions. However, due to the characteristics of wireless link and frequent change of the network topology, the packet loss seriously affects the quality of video streaming applications. In this paper, we propose a REceiver-Driven loss reCOvery Mechanism (REDCOM) to enhance video dissemination over IC-VANET. A Markov chain based estimation model is introduced to capture the real-time network condition. Based on the estimation result, the proposed REDCOM recovers the lost packets by requesting additional forward error correction packets. The REDCOM follows the receiver-driven model of IC-VANET and does not require the infrastructure support to efficiently overcome packet losses. Experimental results demonstrate that the proposed REDCOM improves video quality under various network conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4398-4417
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• 2017

Multi-user Multiple-Input and Multiple-Output (MU-MIMO) has potential for prominently enhancing the capacity of wireless network by simultaneously transmitting to multiple users. User selection is an unavoidable problem which bottlenecks the gain of MU-MIMO to a great extent. Major state-of-the-art works are focusing on improving network throughput by using Channel State Information (CSI), however, the overhead of CSI feedback becomes unacceptable when the number of users is large. Some work does well in balancing tradeoff between complexity and achievable throughput but is lack of consideration of fairness. Current works universally ignore the rational utilizing of time resources, which may lead the improvements of network throughput to a standstill. In this paper, we propose TOUSE, a scalable and fair user selection scheme for MU-MIMO. The core design is dynamic-time-warping-based user selection mechanism for downlink MU-MIMO, which could make full use of concurrent transmitting time. TOUSE also presents a novel data-rate estimation method without any CSI feedback, providing supports for user selections. Simulation result shows that TOUSE significantly outperforms traditional contention-based user selection schemes in both throughput and fairness in an indoor condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.737-738
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• 2013