• Journal of the Korean Wood Science and Technology
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• v.40 no.6
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• pp.431-444
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• 2012

Constituents of timber framed floor affect the insulation performance against impact sound significantly. Among them, installation of massive sound absorbing layer and reinforcement of stiffness of timber floor have been considered as major factors that improve the insulation performance against impact sound. Researches on evaluating the effect of floor constitutions have been carried out through the field measurements for timber framed buildings in Korea. It is concluded that the impact sound pressure level at the relatively lower frequency governs the overall insulation performance, and can be improved by the installation of sound absorbing layer and reinforcement of floor stiffness. Especially, the insulation performance against heavy impact sound was improved significantly when the massive cement mortar layer for floor heating system was installed and the stiffness was reinforced by shortening the joist span using additional beam at the mid-position of original span.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.653-660
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• 2013

Acaiberry(Euterpe oleracea Mart.) was partially substituted from the formula for juak and the subsequent effects on the physiochemical and physical characteristics. And this study was carried out to standardize the recipe of acaiberry-juak. Acaiberry powder was added in 0(control), 1, 3 and 5% substitution ratios by weight per glutinous rice flour. Also, acaiberry puree was added in 3, 6 and 9% substitution ratios by weight water. The moisture contents showed juak with addition of acaiberry contents were lower then control. The diameter of the juak decreased with increasing levels of the added acaiberry powder and puree, whereas the height increased with increasing amount of the powder and puree. The Hunter colorimeteric L-values of the dough and acaiberry-juak decreased as the amount of acaiberry powder and puree increased. Hunter a and b-values both increased with increasing levels of the acaiberry powder and puree. Textural characteristics there were increase in hardness, springiness, chewiness as the amount of acaiberry powder and puree increased(p<.001). Cohesiveness were not significantly different as the level of acaiberry powder and puree increased(p<.001). The anti-oxidant capacity results, anthocyanin, DPPH radical scavenging activity, SOD-like activity, Nitrate-scavenging ability tended to increased by according to the addition acaiberry powder and puree(p<.001). As measured DSC, the onset temperature and enthalpy were accordingly increased during storage period as the acaiberry contents were higher then control. According to sensory evaluation results, the after swallowing, appearance, flavor, taste and texture of juak was acaiberry powder 1% and acaiberry puree 6% proper score is recorded. Overall acceptability of acaiberry juak powder 1%, puree 6% percent of the additives are also the highest mark in the sensory characteristics. Also aciberry powder addition of more than demonstrate a good reputation in the development juak will suggest more appropriate form of puree.

• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.379-390
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• 2011

Purpose: This study was conducted to improve the working conditions of dental technicians, through survey for working conditions related to perform one's duty, the extent of personal exposure to substances hazardous and complaint rate and factor of job stress and subjective symptom on musculoskeletal disorders. Methods: Using four types of structured questionnaires: social and demographic factor; the actual conditions of working space; working conditions; and characteristics of dental technicians, respondents filled in the questionnaires and the results were analyzed statistically. Results: The evaluation of comfort in working place found that satisfaction level on indoor noise was the lowest with 2.6 on a five-point scale and privacy space followed 2.8 point. In reasons for dissatisfaction with job, over workload ranked the highest by 25.4% and role overload had the highest by 39.5% in job stress factors. Based on the results, we could draw conclusion that dental technicians were unsatisfied with role overload and heavy workload a day. In reasons for musculoskeletal symptom prevalence, long-patient work was the highest by 24.1%. It was thought to cause dental technicians need deep procession and long-patient work due to the nature of their job. Conclusion: In conclusion, noise reduction and privacy space are required to improve job efficiency of dental technicians. In addition; we need to think of ways to increase the job satisfaction with adequate rest while deep procession and long-patient working.

• Journal of Korea Water Resources Association
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• v.42 no.9
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• pp.703-713
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• 2009

Dam has very important roles in both water use and flood control. Dam release and runoff from rainfall affect directly to the flood control at the downstream of dam during heavy storm especially. This study evaluates the applicability of a distributed model by applying the GRM (Grid based Rainfall-runoff Model) based on HyGIS (Hydro Geographic Information System) environment to runoff modeling at the downstream of dam where the discharge from dam and rainfall affect simultaneously. In order to do this, Yeoju watershed in Han River basin is selected. Rainfall data and discharge from Chungju regulation dam and Hoengseong dam are applied to runoff simulation. The modeling results are verified with Yeoju water level station, and they show good agreement with observed hydrographs. And this study shows that GRM is able to simulate appropriately the effect of dam discharge and rainfall on watershed runoff.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6551-6557
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• 2015

This paper discusses the surface roughness of corroded reinforcement rebar-in-coil focusing on the quantitative measurement technique using 3D scanner. Reinforcement rebar-in-coil was stacked in site for 0 day, 3 days, 7 days, 14 days and 21 days. And rebar-in-coil was corroded 0.04%, 0.3367%, 0.6157%, 0.7898%, and 1.1965% respectively. Using 3-dimensional scanner, each surface profile of reinforcement rebar-in-coil was established, and surface roughness was measured. Through the tests and analyses of corroded rebar-in-coil, the increase of fractal dimension for each rebar-in-coil was measured as 0.0216, 0.0235, 0.028, 0.0319, and 0.0455 for different stacked periods. Therefore, surface assessment technique using fractal dimension showed similar results with the actual corrosion rate.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.561-569
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• 2012

Study attempts to evaluate the environmental cost and benefit for management of particulate matters of Donghae harbor in Gangwondo. The level of fine dust suspended in the vicinity of the harbor was quite high, exceeding the national standard ($100{\mu}g/m^3$) depending on the places. The test field harbor deals with lots of limestone and coal, so that fine particulates could be generated while loading it and unloading. It was estimated that the direct handling of cargos might produce 12 tons of PM10(Particulate Matters of $10{\mu}m$) a year. In addition, heavy vehicles for transportation of various cargos including raw materials emit huge amount of diesel soots and cause to redispersion of road dust. The local government spends more than 2 billion won every year, and it contributes to reduce the atmospheric dust. According to the prediction of cost to benefit, it will present the effectiveness in 720 % maximum and at least 240 %.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.239-254
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• 2004

It has been debating about conducting and interpretating of 2-year rodent carcinogenicity bioassay. Although some criticisms arising in usefulness, it has been still known that long-term carcinogenicity studies using rodents would be the only assay system to predict any possible human risks, which would not be replaced. Both regulatory agencies and academies have developed some assay models, however, there have been controversy whether those study designs and interpretations are based on sound scientific rationale and validated data. Such kinds of issues including choice of species/strain, dose level selection, duration of study, number of animals per group, historical control data, monitoring parameters, terminal investigations, peer review, statistics, alternative assay models, interpretation of neoplastic lesions, and risk assessments, were reviewed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1307-1323
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• 2014

With the exhaustion of global IPv4 addresses, IPv6 technologies have attracted increasing attentions, and have been deployed widely. Meanwhile, new applications running over IPv6 networks will change the traditional traffic characteristics obtained from IPv4 networks. Traditional models obtained from IPv4 cannot be used for IPv6 network monitoring directly and there is a need to investigate those changes. In this paper, we explore the flow features of IPv6 traffic and compare its difference with that of IPv4 traffic from flow level. Firstly, we analyze the differences of the general flow statistical characteristics and users' behavior between IPv4 and IPv6 networks. We find that there are more elephant flows in IPv6, which is critical for traffic engineering. Secondly, we find that there exist many one-way flows both in the IPv4 and IPv6 traffic, which are important information sources for abnormal behavior detection. Finally, in light of the challenges of analyzing massive data of large-scale network monitoring, we propose a group flow model which can greatly reduce the number of flows while capturing the primary traffic features, and perform a comparative measurement analysis of group users' behavior dynamic characteristics. We find there are less sharp changes caused by abnormity compared with IPv4, which shows there are less large-scale malicious activities in IPv6 currently. All the evaluation experiments are carried out based on the traffic traces collected from the Northwest Regional Center of CERNET (China Education and Research Network), and the results reveal the detailed flow characteristics of IPv6, which are useful for traffic management and anomaly detection in IPv6.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.202-206
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• 2012

In order to prepare rice vinegar, $takju$ fermentation was performed, using two different compositions; cooked rice supplemented with $Rosa$ $rugosa$ Thunb. (CR-R) and uncooked rice supplemented with $Rosa$ $rugosa$ Thunb. (UR-R). After ethanol fermentation, ethanol contents of $takju$ were adjusted to 6.0%, and then acetic acid fermentation was carried out using $Acetobacter$ $aceti$ at $30^{\circ}C$ with 200 rpm for 9 days. Supplementations of 1% acetic acid to $takju$ prior to acetic acid fermentation were a critical step in achieving a successful fermentation; final organic acid contents increased in a dose dependent manner. A higher content of organic acids, 1.6-6.9%, was found in UR-R vinegar. The level of free amino acid and GABA in UR-R vinegar was higher than that of CR-R vinegar, with glutamic acid and arginine, as the major amino acids. This finding demonstrates that heating process of rice prior to ethanol fermentation affects the quality of vinegar significantly.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.113-120
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• 2009

Through the automatic sensing of the environment, USN technology can give the best services. In this work, we have developed an active RFID system and examined its performance. By implementing it into water quality sensors, we constructed a system that can detect diverse indoor/outdoor environment and provide information about the pollution level obtained from the temperature and PH sensors. Our RF system had an internal Print-on-PCB antenna for the miniaturization of the tag. We used a RF transceiver CC2510 chipset of TI company to realize the active RFID function. By using RSSI constants obtained, we performed the evaluation of real time location accuracy with a software written in Labview. Among 10 arbitrary locations, we obtained average measurement errors of 1.69 m in x axis and 1.66 m in y axis. This technology can be applied to logistics, environmental monitoring, prevention of missing children and various applications.