• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.401-412
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• 2020

This study analyzed the causes of warehouse fires using a creative problem-solving technique called TRIZ. It identified preventive measures by applying 4M. The results are as follows. First, this study examined the inconsistency among the causes of warehouse fires using TRIZ. Second, it analyzed human factors and fire prevention measures in warehouses such as safety standards for managers, and methods for the promotion of safety consciousness among workers, and for the reinforcement of construction technology for sandwich panel workers. Third, it identified the mechanical and facility factors and fire prevention measures in warehouses such as safety facilities, the expanded installation of safety devices, the adoption and development of fire suppression equipment, and the deployment of methods to improve the fire resistance of sandwich panels. Fourth, it presented working and environmental factors and fire prevention measures in warehouses such as the tightening of safety precautions and the supervision of working methods, and setting fire partitions both in loading places and based on performance-based design. Finally, it proposed managerial factors and fire prevention measures in warehouses such as specific targeting for firefighting with low fire hazards, reviewing the material quality regulations of non-combustible or higher for sandwich panels in the specific target of firefighting that cannot apply fire safety standards, installing sprinklers in cold storage, and mandating the installation of automated facilities with retroactive application regardless of the floor area in the warehouse with a sandwich panel structure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.3 s.345
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• pp.49-58
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• 2006

In this paper, a curve-fitting channel estimation method is proposed for orthogonal frequency division multiplexing (OFDM) system in a time-varying frequency-selective fading channel. The method can greatly improve channel state information (CSI) estimation accuracy by performing smoothing and interpolation through consecutive curve-fitting processes in both time domain and frequency domain. It first evaluates least-squares (LS) estimates using pilot symbols and then the estimates are approximated to a polynomial with proper degree in the LS error sense, starting from one preferred domain in which pilots we densely distributed. Smoothing, interpolation, and prediction are performed subsequently to obtain CSI estimates for data transmission. The channel estimation processes are completed by smoothing and interpolating CSI estimates in the other domain once again using the channel estimates obtained in one domain. The performance of proposed method is influenced heavily on the time variation and frequency selectivity of channel and pilot arrangement. Hence, a proper degree of polynomial and an optimum approximation interval according to various system and channel conditions are required for curve-fitting. From extensive simulation results in various channel environments, we see that the proposed method performs better than the conventional methods including the optimal Wiener filtering method, in terms of the mean square error (MSE) and bit error rate (BER).

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.6
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• pp.25-35
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• 1998

The control system architecture in switching systems have undergone numerous changes to provide various call processing capability needed in telecommunication services. During call processing in a distributed switching control environment, the delay effect due to communication among main processors or peripheral controllers is one of the limiting factors which affect the system performance. In this paper, we propose a performance model for an IPC(Inter Processor Communication) interface hardware block which is required on the ATM cell-based message processing in a distributed ATM exchange system, and analyze the primary causes which affect the processor performance through the simulation. Consequently, It can be shown that the local CPU of the several components(resources) related to the IPC scheme is a bottleneck factor in achieving the maximum system performance from the simulation results, such as the utilization of each processing component according to the change of the input message rate, and the queue length and processing delay according to input message rate. And we also give some useful results such as the maximum message processing capacity according to the change of the performance of local CPU, and the local CPU maximum throughput according to the change of average message length, which is applicable as a reference data for the improvement or expansion of the ATM control system.

• Korea journal of population studies
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• v.23 no.2
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• pp.113-141
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• 2000

The aim of this paper is to project the state of the labor farce and employment in Korea from 2000 to 2005. The labor market in Korea is experiencing significant changes with the rapid development of Information and Telecommunication Technology (ICT) and the transition of the Korean economy into a knowledge-based economy. On the labor supply side, it is expected that the growth of the labor force will be sluggish; baby boomers will become the middle-aged, while the proportion of senior citizens, the highly educated and the female labor force will grow fast. These changes will alter the human resources management system in business sectors. Moreover, the permanent employment relationship, the hierarchy system and the seniority-based wage system are all expected to change. On the labor demand side, the employment share in highly skilled. knowledge-intensive industries will grow faster than the rest of the economy in tandem with the quickly growing output share of these industries. Especially, more jobs will be created in the ICT industries. The proportion of labor in highly skilled and professional occupations will also grow faster than in other occupations. At the same time, the employment share of female workers will grow more quickly than that of the male workers. These changes, however, may worsen income inequalities and/or increase the unemployment rate when workers do not have the suitable skills or knowledge required by the knowledge-based economy. To avoid this, it is necessary for the government to build up a lifetime learning system for workers.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.374-381
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• 2008

Spatial and temporal changes of fish communities were studied at four study sites in the Cheonggye Stream from October 2005 to August 2006 after the rehabilitation process. During the survey period, 19 species in 6 families were sampled. Species Rhynchocypris oxycephalus and Zacco platypus were identified as dominant species. Korean endemic species such as Acheilognathus yamatsutae and Zacco koreanus were observed in the sites. Overall, species richness and abundance increased as time passes after the rehabilitation, reflecting colonization process of the fish community. Meanwhile species richness and abundance were higher at the downstream than at the upstream. Community indices such as dominant index, richness index and diversity index showed also similar spatial and temporal pattern. Nonmetric multidimensional scaling (NMDS), multivariate ordination technique, was used to analyze spatial and temporal variation of the fish communities, and the results showed spatial variation of fish communities with high species richness at downstream as well as the temporal variation of fish communities with high values of species richness and diversity index at later part of the study period, presenting colonization process of the fish community after the rehabilitation project.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.275-281
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• 2012

Thermal distribution in soils must be considered in engineering designs and constructions, including estimates of frost heave and thaw settlement, infrastructure in cold regions, and geothermal systems. Because thermal conductivity is a key parameter for evaluation of thermal distribution in soils, it must be accurately estimated. The thermal conductivity of fine-grained soils has been widely studied in recent years; however, few studies have reported a reliable method for experimental measurement. The present study presents the results of an experimental investigation of the thermal conductivity of a saturated kaolinite-silica mixture with respect to the variation of dry density. Thermal conductivities were measured in Constant Rate of Strain (CRS) consolidation tests, and the experimental data were analyzed to evaluate the accuracy of the new measurement system. In addition, we present an evaluation method for predicting thermal conductivity in fine-grained soils.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.5
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• pp.28-34
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• 2008

The real-time biomedical signal monitoring is a very important factor to realize the ubiquitous healthcare environment. Most of these devices for monitoring the biomedical information get the PPG signal from the user, and these signals are utilized for monitoring their health. It is inconvenient to get the PPG because the user should wear the finger probe with his finger for measuring the PPG signal. Also it is difficult to get the PPG correctly, because of the motion artifacts from the movement of the user. In this paper, we develop the watch type biomedical signal monitoring system without the finger probe, and propose the new algorithm for reducing the motion artifacts from the PPG signal. We designed the system which gets the PPG from the sensor on the wrist band strip. As compared with the finger probe type, this system we proposed is more affected by the motion artifacts. So to filter this motion artifacts, we propose the new method; the improved PMAF(Periodic Moving Average Filter) method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1199-1207
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• 2015

One-person household is increasing by the growth of unemployment, divorce, aging in Korea. In particular, One-person households have rapidly increased around Farming & Fishing Regions. In this regard, this research aims to suggest the directions of housing supply for one-person households suitable for Farming & Fishing Regions by investigating the characteristics of one-person households in the social, economic, and physical aspects. This study found out that one-person households could be divided into two groups; one group lived in industrialized Farming & Fishing Regions and the other group lived in traditional Farming & Fishing Regions. For one-person households living in industrialized Farming & Fishing Regions, it is necessary to provide age-mixed residential sites where companies and manufacturers are condensed. On the other hand, for the one-person households living in traditional Farming & Fishing Regions, it in necessary to provide multi-person housing units for increasing the quality of life ofne-person households.

• Journal of Yeungnam Medical Science
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• v.24 no.1
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• pp.1-10
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• 2007

The chronic fatigue immune dysfunction syndrome (abbreviated CFIDS or CFS) is a disorder characterized by debilitating fatigue(over 6 months.), along with cognitive, musculoskeletal, and sleep abnormalities. The etiology of this illness is unlikely to be a single agent. Findings to date suggest that physiological and psychological factors work together to predispose and perpetuate the illness. Diagnosis is made difficult by the nonspecific clinical findings and no available diagnostic testing. With no known cause or cure for the chronic fatigue and immune dysfunction syndrome, treatment is based on relieving symptoms and improving the quality of life of affected patients. There is emerging evidence that chronic fatigue syndrome may be familial. In the future, studies will examine the extent to which genetic and environmental factors play a role in the development of chronic fatigue syndrome. Most patients with CFS have psychiatric problems such as a generalized anxiety disorder, or major or minor depression, therefore, these mental health disorders may be correlated with the pathophysiology of the CFS. The treatment for CFS must be individualized, due to the heterogeneity of the CFS population. Also the treatment of CFS is built on a foundation of patient-physician relationship, respect and advocacy.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.72-81
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• 2004

For disposal food wastes which is about 30% portion of tatal organic wastes, vermicomposting is more environmental-friendly treatment than lanfill, incineration, etc. Recently, the interest has been increasing but there are many problems on management of vermicopmposting in field especially. This study was conducted to investigate an optimal factors, which are limit NaCl conc., the mixing rate of food wastes and casting for growth of an earthworm related to efficient vermicomposting. The limit conc. of NaCl was 0.5% and in case of feeding food wastes to earthworms as a prey only, most earthworms were dead in a few hours due to excessive degradation of organic materials and high NaCl conc. However as feeding with the casting of proper mixing rate(3:7), most earthworms were survived until finishing composting. It was investigated the increaser degree of matureness of food wastes, the higher conc. of NaCl, therefore for efficient vermicomposting, it seemed proper mixing rate of food wastes and the casting is better than matureness of food wastes. and the most suitable mixing rate was 3:7 food wastes and the casting.