• Journal of Energy Engineering
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• v.23 no.1
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• pp.7-20
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• 2014

The optimal woodchip production system was developed and the production cost of a forest woodchip fuel was calculated for utilizing the pitch pine, which covers around 480,000ha nationwide. the marginal price of the woodchip fuel considering the factor of supply price, electricity and heat selling price as well as capacity factor were suggested and the economic sensitivity analysis was conducted for various scenario. The most important variable which determine economic feasibility was a fuel cost for the power generation facility. If the electricity price is higher than the current SMP(System Marginal Price) or the capacity factor is higher than 80%, there fully is a benefit to consume the woodchip fuels produced in the suggested production system in this study. In addition, the additional benefit becomes more obvious when considering REC(Renewable Energy Certificate) and CDM(Clean Development Mechanism). Therefore, it is strongly suggested for domestic power generation sector to utilize the forest biomass fuel to achieve the obligatory target of RPS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1B
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• pp.29-40
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• 2004

In this paper, we propose a new early congestion detection and notification technique called QR-AQM. Unlike RED and it's variation, QR-AQM measures the total traffic rate from TCP sessions, predicts future network congestion, and determine the packet marking probability based on the measured traffic rate. By incorporating the traffic rate in the decision process of the packet marking probability, QR-AQM is capable of foreseeing future network congestion as well as terminating congestion resolution procedure in much more timely fashion than RED. As a result, simulation results show that QR-AQM maintains the buffer level within a fairly narrow range around a target buffer level that may be selected arbitrarily as a control parameter. Consequently, compared to RED and its variations, QR-AQM is expected to significantly reduce the jitter and delay variance of packets traveling through the buffer while achieving nearly identical link utilization.

• Explosives and Blasting
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• v.29 no.2
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• pp.67-80
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• 2011

Recently, the number of structure demolitions has increased in both civil and architecture fields due to various reasons such as redevelopment of a city, utilization of sites and restoration of deteriorated structures. In the past, domestic shell structures had been constructed with brick masonry and they were not high. Therefore, their demolition had been executed with ease. Recently, however, taller reinforced concrete shell structures have become a target for the destruction. Under these circumstances, how to efficiently demolish a structure and how to minimize effects of the destruction on environment including vibration and noise have become a main issue. One of the possible solutions is the explosive demolition. In this study, a case of explosives demolition of the stack, which is located in Jeju Thermal Power Plant in Republic of Korea and is 70 m tall, is addressed. In order to fall down the structure against the desired direction, 13.5 kg dynamite and 100 electric detonators were used.

• YAKHAK HOEJI
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• v.57 no.5
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• pp.369-375
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• 2013

Objective: Using the Korean Health Panel data (KHP) of 2008 and 2009, this paper analyzed the effect of antihypertension medication adherence on the changes in medical service utilization and medical expenditure in the next year. Method: Through a face-to-face interview survey, KHP has provided an extensive data on demographic characteristics, medical utilizations behavior, medical expenditure and health behaviors of the targeted households and their members since 2008. KHP is recognized as highly accurate regarding medical expenditure in that it makes the target households to record 'Health diary' whenever they use healthcare service, which could minimize their cognitive bias or memory distortion. The 2010 KHP data was based on the interview from 6,432 households and 19,697 household members. Two part model was used to explore the effects of medication adherence on medical use (logistic regression analysis) and medical expenditures (OLS). Result: Our study result demonstrated that the 74.7% of the patients who strictly adhere to their medication in both years, in 2008 and in 2009, were likely to use inpatient service in 2010. This shows the noncompliant patients were in fact use emergency service less than the compliant patients. Conclusion: Based on our analysis, this paper concludes that the high medication adherence of hypertensive patients could contribute to reduce the emergency service use. Therefore it is highly recommendable for the Korean government and the insurer, NHIS, to actively invest in developing education and promotion program to improve medication adherence among hypertensive patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.515-524
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• 2014

In this paper, The investment prioritization model was investigated for keeping the service level of mooring facilities more than the target level of management with a limited budget in the right time. Network level prioritization criteria of the national scale was developed to take into criteria index and quantitative evaluation, management authority's opinion. Delphi method was conducted maintenance exports of mooring facilities over twice for verifying the validity and adequacy. In order to improve the objectivity of criteria, the criteria for evaluating the utilization of port facilities is presented form yearly facility traffic/facility's length, the result of the analysis of facility traffic data. The investment prioritization criteria of mooring facilities is expected to be utilized for more efficient and national budget distribution applied to the maintenance budget plan of nationwide.

• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.67-82
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• 2013

This paper presents multi-fidelity modeling and simulation (M&S) methodology to enhance simulation performance of engineering-level defense models. In this approach, a set of models with varying degrees of fidelity is exercised to reduce computational expense maintaining a similar level of system effectiveness. For multi-fidelity M&S principles, this paper defines model fidelity from two perspectives (i.e., model behavior and execution), and suggests the Fidelity Change Point (FCP) to specify the fidelity conversion. With these concepts, this paper centers on three ideas: 1) two models' structure which are the Behavioral-Fidelity Interchangeable Model (B-FIM) and the Executional-Fidelity Interchangeable Model (E-FIM), 2) modeling formalism, and 3) a simulation algorithm to support them. From an abstract case study regarding a target tracking scenario with the utilization of the proposed method, we can gain interesting experimental results regarding the enhancement of simulation performance. Finally, we expect that this work will serve various M&S-based analysis areas for enhancing simulation performance.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.3
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• pp.446-457
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• 2017

In order to reduce the size of frame memory or bus bandwidth, frame memory compression (FMC) recompresses reconstructed or reference frames of video codecs. This paper proposes a novel FMC design based on discrete wavelet transform (DWT) - set partitioning in hierarchical trees (SPIHT), which supports fine-scalable throughput and is area-efficient. In the proposed design, multi-cores with small block sizes are used in parallel instead of a single core with a large block size. In addition, an appropriate pipelining schedule is proposed. Compared to the previous design, the proposed design achieves the processing speed which is closer to the target system speed, and therefore it is more efficient in hardware utilization. In addition, a scheme in which two passes of SPIHT are merged into one pass called merged refinement pass (MRP) is proposed. As the number of shifters decreases and the bit-width of remained shifters is reduced, the size of SPIHT hardware significantly decreases. The proposed FMC encoder and decoder designs achieve the throughputs of 4,448 and 4,000 Mpixels/s, respectively, and their gate counts are 76.5K and 107.8K. When the proposed design is applied to high efficiency video codec (HEVC), it achieves 1.96% lower average BDBR and 0.05 dB higher average BDPSNR than the previous FMC design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1025-1032
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• 2017

In this paper, the level of service (LOS) is defined for high-speed railway links and rolling stocks. Based on this LOS, how to manage high-speed railway facility is also suggested. The LOS is divided into 6 levels from A to F. The measurement of effectiveness (MOE) for railway links is derived from the relationship between a total delay time and a railway link utilization ratio. Another MOE, volume over capacity (V/C), is also proposed. On the other hand, the LOS for high-speed railway rolling stocks is based on the density of people in a rolling stock. Above all, LOS D is defined to the total number of seats. Then, LOS A is 50% of the LOS D, LOS B is 70% of the LOS D, LOS C is 90% of the LOS D and LOS D~F is defined as the maximum seats and standing people at the level of each. Finally, a method to manage high-speed railway links and rolling stocks is proposed in order to keep the level of service at the target by the government.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.155-161
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• 2015

Technetium-99m (^99mTc) is an important, short-lived decay product of molybdenum-99 (⁹⁹Mo), and it is considered the backbone of the modern nuclear diagnostic procedures. Since fission of ²³⁵U is the main source of production of ⁹⁹Mo, either highly-enriched uranium (HEU) targets or low-enriched uranium (LEU) targets are irradiated in the research reactors. The use of LEU targets is being promoted by the international community to avoid the proliferation issues linked with the use of HEU. In order to define the waste management strategy at the planning stage of establishment of an LEU based ⁹⁹Mo production facility, the impact of the use of LEU targets on the radioactive waste stream of the ⁹⁹Mo production facility was analyzed. Because the volume of uranium waste is estimated to increase six times, the use of high uranium density targets and the utilization of hot isostatic pressing were recommended to reduce the increased waste volume from the use of LEU based targets.

• 전자공학회논문지 IE
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• v.43 no.1
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• pp.46-51
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• 2006

Recently, smart card system which is known as easy to portable and also safe from physical, electrical, and software attack is observed to manage information that becomes the target of security in safety. And java card graft upon java technology to smart card platform is having very good advantage with object-oriented techniques and also, java card have the open type OS that can show the same action in different hardware characteristic which allows various application programs. In this paper, we introduced independent execution characteristic of java platform because being set to each smart card was uncomfortable till now and we designed access control member card that allows several administrators in different access privilege by single card using java card. Several administrators can approach to various information of file type that is included on issued card to user by using different PIN. In the proposed method, confirmation of personal information, administration contents update, demand by contents, is possible by single card. At this moment, wish to do safer user certification that improve security limitation which is from PIN, used for user certification, and signature data. In the proposed method, as design and implementation of utilization technology of java card, biometrics, user certification which uses multi PIN, provide that more safety and conveniently.