• Proceedings of the KSR Conference
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• 2008.11b
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• pp.93-99
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• 2008

The SeoulMerto, operating subway line No.$1{\sim}4$, was constructed in the metropolitan Seoul with the highest population. When it was built, the design was challenged to sharp curved tracks considering the protection of buildings, cultural assets, the connection to ground roads and rivers as well as to elevated railway in some parts. Lots of residential apartments and business complex have gradually increased in the area around subway stations and railway lines according to the urban development. Consequently, Requirements of better quality of life and comfortable environment caused the citizen complain for the noise. It has become one of serious social issues. In this paper, Noise level was analyzed using noise map measured in the running train of all routes. The analysis on the noise level was conducted according to railway type, track components type, seasonal type, retirement degree of the vehicle and subway station. Especially, Noise characteristics were analyzed by noise level data measured in the inside and outside of the train with geometry types of the concrete track. This study will contribute fundamental data for the "The Development of Sound-Absorbing Block on Concrete Track" promoted on The National R&D Project.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.701-706
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• 2006

Groundwater heat pump systems are the oldest of the ground-souce systems and it has various type. Standing column well type are must be located in hard rock geology site and produce sufficient water for the conventional open loop system. These system are indirect type(the building circulating loop and ground water are intercept). Existence of the exchanger the foundation protect water quality to use of open loop. The design of open loop system are concern on the power requirements. An experimental study was analysis the extremely heating operation COP of ground water heat pump system. Operation efficiency of the 50RT systems shows that, COP $2.9{\sim}5.0$ in heating operation. And generally it shows 3.4.

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.44-49
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• 2001

In general. requirements for QoS are different according to the type of services in wireline and wireless ATM, and real-time video service is more sensitive to cell transmission delay than to cell loss. Existing handoff schemes emphasizing prevention of cell loss had limitations in cell transmission delay to satisfy QoS. In this paper, a novel scheme to transmit ATM cells with low CLP (when CLP = 0) prior to others and discarding cells with high CLP (when CLP = 1) in ATM cell header among cells to be forwarded during handoffs in real-time VBR service is proposed. The proposed scheme is proven to be suitable for the satisfaction of QoS and appropriate for fast handoffs by giving high CLP value to less meaningful MPEG frames through simulations.

• Advances in concrete construction
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• v.5 no.6
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• pp.671-683
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• 2017

Commonly used concrete in general, consists of cement, fine aggregate, coarse aggregate and water. Natural river sand is the most commonly used material as fine aggregate in concrete. One of the important requirements of concrete is that it should be durable under certain conditions of exposure. The durability of concrete is defined as its ability to resist weathering action, chemical attack or any other process of deterioration. Durable concrete will retain its original form, quality and serviceability when exposed to its environment. Deterioration can occur in various forms such as alkali aggregate expansion, freeze-thaw expansion, salt scaling by de-icing salts, shrinkage, attack on the reinforcement due to carbonation, sulphate attack on exposure to ground water, sea water attack and corrosion caused by salts. Addition of admixtures may control these effects. In this paper, an attempt has been made to replace part of fine aggregate by tailing material and part of cement by fly ash to improve the durability of concrete. The various durability tests performed were chemical attack tests such as sulphate attack, chloride attack and acid attack test and water absorption test. The concrete blend with 35% Tailing Material (TM) in place of river sand and 20% Fly Ash (FA) in place of OPC, has exhibited higher durability characteristics.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.328-335
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• 2013

Due to the rapid advancement of auto-refractor technology, most optometry shops provide refraction services. Despite their speed and convenience, the measurement values provided by auto-refractors include a significant degree of error due to psychological and physical factors. Therefore, there is a need for repetitive testing to obtain a smaller mean error value. However, even repetitive testing itself might not be sufficient to ensure accurate measurements. Therefore, research on a method of measurement that can complement auto-refractor measurements and provide confirmation of refraction results needs to be conducted. The customized optometry model described herein can satisfy the above requirements. With existing technologies, using human eye measurement devices to obtain relevant individual optical feature parameters is no longer difficult, and these parameters allow us to construct an optometry model for individual eyeballs. They also allow us to compute visual images produced from the optometry model using the CODE V macro programming language before recognizing the diffraction effects visual images with the neural network algorithm to obtain the accurate refractive diopter. This study attempts to combine the optometry model with the back-propagation neural network and achieve a double check recognition effect by complementing the auto-refractor. Results show that the accuracy achieved was above 98% and that this application could significantly enhance the service quality of refraction.

• Journal of the FoodService Safety
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• v.1 no.1
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• pp.45-51
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• 2020

This study sought to understand the requirements of registered institutions and parents of beneficiary children's through a satisfaction survey conducted at Center for Children's Foodservice Management (CCFSM) and to improve quality to create a model example of site-based meal safety management in accordance with population trends. In 2019, the comprehensive satisfaction level of the director and parents rose 2.4 points and 2.9 points, respectively, compared to the previous year, and the comprehensive satisfaction level of the director and parents continued to rise from 2015 to 2019. The gap between the highest and lowest institutions is narrowed to 13.5 points year-on-year from 21.4 points. National Institute of Food and Nutrition Service will need to make efforts to upgrade regional centers through (Human Resource Development(HRD) training to strengthen their job-specific capabilities and minimize the standard deviation of each center. Since local centers are distributed across the country and have field-oriented service support systems, CCFSM will need to manage the healthy eating habits of the underprivileged, provide information necessary to establish proper eating habits, strengthen education, and establish a customized food safety service system.

• Journal of the Korean Institute of Rural Architecture
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• v.21 no.3
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• pp.9-16
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• 2019

The increase in housing energy costs due to deteriorated rural house is directly related to the quality of life of rural residents, which is fundamental challenge for the government. In this study, we analyzed the current energy performance and the effect of housing energy efficiency improvement after remodeling of the four rural houses over 20 years old considering the rural housing type. As the result, the heating energy requirements of the unit surface is very high, and the effect was predicted to vary by housing after improved thermal insulation. This means that the cost of housing energy will be utilized as a target selection criterion or post-effect for the rural house remodeling project. In addition, the energy performance was analyze for the compact houses, which are in demand, mainly for young rural immigrants. As the result, the energy performance is very efficient.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.71-77
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• 2017

As the automobile industry has shifted to software, the Automotive SPICE standard has been established to ensure efficient product development process and quality. In the assessment model, the HIS Scope is the minimum standard for small and medium automotive electric companies to meet OEM requirements. However, in order to achieve the HIS Scope, the output of each process stage that meets the verification criteria of Automotive SPICE must be created. In particular, the test phase takes a lot of resources, which is a big burden for small and medium-sized companies. In this paper, we propose a methodology for creating test cases of software integration test phase based on UML sequence diagram, which is a software design phase of Automotive SPICE HIS Scope, by applying behavior model based testing method. We also propose a tool chain for automating the creation process. This will reduce the resources required to create a test case.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2258-2276
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• 2019

Resource sharing is one of the main goals achieved by network virtualization technology to enhance network resource utilization and enable resource customization. Though resource sharing can improve network efficiency by accommodating various users in a network, limited infrastructure capacity is still a challenge to ultra-low latency service operators. In this paper, we propose an inter-slice resource borrowing schema based on the device-to-device (D2D) potentiality especially for ultra-low latency transmission in cellular networks. An extended and modified Kuhn-Munkres bipartite matching algorithm is developed to optimally achieve inter-slice resource borrowing. Simulation results show that, proper D2D user matching can be achieved, satisfying ultra-low latency (ULL) users' quality of service (QoS) requirements and resource utilization in various scenarios.

• Electronics and Telecommunications Trends
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• v.34 no.5
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• pp.81-90
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• 2019

The data rate for transmission through fiber-optic cables has increased to 400 Gbps in single-wavelength channels. However, speeds up to 1 Tbps are required now to meet the ever-increasing bandwidth demand driven by the diverse requirements of contemporary applications for high-quality on-demand video streaming, cloud services, various social media, and emerging 5G-enabled applications. Because the data rates of the per-channel optical interfaces depend strongly on the operational speed of the optoelectronic devices used in optical transceivers, ultrahigh-speed photonic devices and components, and eventually, chip-level transmitter and receiver technologies, are essentially required to realize futuristic optical transceivers with data rates of 1 Tbps and beyond. In this paper, we review the recent progress achieved in high-speed optoelectronic devices, such as laser diodes, optical modulators, photodiodes, and the transmitter-receiver optical subassembly for optical transceivers in data centers and in metro/long-haul transmission.