• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.2
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• pp.97-109
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• 2019

Degree days have been determined using temperature data measured at nearby weather stations to a site of interest to produce information for supporting decision-making on agricultural production. Alternatively, the data products of Moderate Resolution Imaging Spectroradiometer (MODIS) can be used for estimation of degree days in a given region, e.g., Korean Peninsula. The objective of this study was to develop a simple tool for processing the MODIS product for estimating cooling degree days (CDD), which would help assessment of heat stress conditions for a crop as well as energy requirement for greenhouses. A set of scripts written in R was implemented to obtain temperature profile data for the region of interest. These scripts had functionalities for processing spatial data, which include reprojection, mosaicking, and cropping. A module to extract air temperature at the surface pressure level was also developed using R extension packages such as rgdal and RcppArmadillo. Random forest (RF) models, which estimate mean temperature and CDD with a different set of MODIS data, were trained at 34 sites in South Korea during 2009 - 2018. Then, the values of CDD were calculated over Korean peninsula during the same period using those RF models. It was found that the CDD estimates using the MODIS data explained >74% of the variation in the CDD measurements at the weather stations in North Korea as well as South Korea. These results indicate that temperature data derived from the MODIS atmospheric products would be useful for reliable estimation of CDD. Our results also suggest that the MODIS data can be used for preparation of weather input data for other temperature-based agro-ecological models such as growing degree days or chill units.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.272-278
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• 2018

Traffic volume has been greatly increasing due to urban development and the improvement of living standards, and many complaints are being raised due to the increasing road noise. As a countermeasure against these problems, highly soundproof walls are installed on the sides of roads. However, the ability to bear wind loads is a major design requirement for soundproof walls, which contributes to the exponential increases in construction costs and restricts the height of the walls. The aim of this study is to improve the performance of soundproof walls and to dramatically reduce wind loads while maintaining excellent price competitiveness. Based on Helmholz's resonator theory, a new concept is proposed for a ventilation-type soundproofing plate that can pass through a fluid like air and reduce noise. A full-scale metal soundproofing plate was produced to satisfy the quality standards of highways by conducting a sound-pressure transmission-loss test, wind tunnel test, and material quality test. To verify the reliability, the wall was manufactured and installed, and the sound insulation effect was examined by measuring the noise over time. In the future, ventilated soundproof walls on roads could create a pleasant living environment due to the high noise-insulation effect.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.396-405
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• 2019

The speech privacy of closed office rooms located in a university campus was measured and assessed in terms of SPC (Speech Privacy Class) values. The measurements of two quantities, the LD (Level Difference) between a source and a receiving room, and the background noise level ($L_b$) at the receiving room were carried out in 5 rooms located in 3 different buildings in the university campus. Each of the 5 rooms was adjacent to both offices and corridors through walls. The TL (Transmission Loss) between the source and the receiver room was also measured to compare the difference of two standard methods, ASTM E2836-10 and KS F 2809. The present results show that the speech privacy of the 5 office rooms is not met the requirement for a minimum SPC values of 70. A minimum LD value of 41 dB between the source and the receiver room should be achieved for having a SPC value of 70 when the mean measured value of $L_b$ at the receiving room is 29.2 dB. That is, the TL(avg) value averaged over the octave bands from 160 Hz to 5000 Hz between the source and the receiver room should be or greater than 40 dB. The most important architectural factor influencing the LD value is the presence of openings, such as doors, and windows, on the adjacent walls between the source and receiving room. Therefore, if the opening of the adjacent wall is replaced by an opening with high sound insulation, the appropriate SPC value of the research and office rooms can be achieved.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.343-347
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• 2011

Due to the strong dependence on fossil fuels within the history of human progress, it leads to disaster of the whole world like flood, shortage of water and extinction of the species. In order to curb carbon dioxide emissions, many technologies are being developed. Among them, porous carbon materials have important advantages over other absorbent, such as high surface area, thermal and chemical resistance, low cost, various pore distribution and low energy requirement for their regeneration. Carbon capture and storage (CCS) has attracted the significant research efforts for reducing green house gas emission using several absorbent and process. Moreover, the absorbent are used for the separation of bio mass gas that contains methane which is considered a promising fuel as new green energy resource. In this review, we summarized the recent studies and trend about the porous carbon materials for CCS as well as separation from the biogas.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.63-70
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• 2003

In the modern electronic world, the authentication of a person is an important task in many areas of online-transactions. Using biometrics to authenticate a person's identity has several advantages over the present practices of Personal Identification Numbers(PINs) and passwords. To gain maximum security in the verification system using biometrics, the computation of the verification as well as the store of the biometric pattern has to be taken place in the security token(smart card, USB token). However, there is an open issue of integrating biometrics into the security token because of its limited resources(memory space, processing power). In this paper, we describe our implementation of the USB security token system having 206MHz StrongARM CPU, 16MBytes flash memory, and 1MBytes RAM. Also, we evaluate the performance of a light-weighted In-gerprint verification algorithm that can be executed in the restricted environments. Based on experimental results, we confirmed that the RAM requirement of the proposed algorithm was about 6.8 KBytes and the Equal Error Rate(EER) was 1.7%.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.607-626
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• 2021

The purpose of this study is to verify the effect of leader's managerial coaching behavior on employees' innovative behavior and to confirm the mediating effect of entrepreneurship and the moderating effect of LMX(Leader-Member Exchange). Hypotheses were established based on prior research and variety of theories including broaden-build theory and self-efficacy theory. The survey was accessed via the online, 279 employees over 20's or older, who have worked in various domestic organizations were participated. SPSS 25.0 and AMOS 25.0 were used to verify the reliability and validity of the collected data, and the hypothesis was analyzed by SPSS process macro 3.0. The study found that leader's managerial coaching behavior has positive effects on both employees' entrepreneurship and innovative behavior and that entrepreneurship has mediating effect between leader's managerial coaching behavior and an employees' innovative behavior. The results of this study suggested leader's managerial coaching behavior is a prominent factor in facilitating innovative behavior among employees. Implications include an organizational requirement to develop systems for initiating effective managerial coaching behavior in leadership, and for improvement of both entrepreneurship and LMX among employees.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.67-72
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• 2022

Concrete prevents corrosion of reinforcing bars due to its strong alkalinity. However, in the sea, strong alkali components with a pH of 12 to 13 are eluted, which adversely affects the ecological environment and growth of marine organisms. In this study, the mechanical properties and durability of the low alkali mortar were evaluated for the development of a low alkali mortar for the 3D printed artificial reefs. As a result of evaluation of strength characteristics, the α-35 mixture, which were produced with fly ash, silica fume and α-hemihydrate gypsum, satisfied the strength requirement 27 MPa in terms of compressive strength. As a result of pH measurement, it was found that mixing with alpha-type hemihydrate gypsum resulted in minimizing pH due to the the formation of calcium sulfate instead of calcium hydroxide production. As a result of the chloride ion penetration resistance test, the α-35 mixture exhibited the best performance, 3844C. As a result of measuring the length change over time, the α-35 mixture showed the shrinkage 33.5% less compared to the Plain mix.

• Journal of agricultural medicine and community health
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• v.47 no.4
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• pp.229-241
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• 2022

Purpose: This study was attempted to identify the demographic characteristics, depression, and dietary quality of elderly patients with type 2 diabetes, and to identify the difference in food quality according to these variables. Methods: The subjects of the study were 216 elderly patients with type 2 diabetes over the age of 65 visiting elderly welfare centers and senior citizens' centers in G city and H districts. Data were collected from December 2020 to July 2021. The collected data were analyzed by descriptive statistics, t-test and one-way ANOVA using IBM SPSS Statistics 21 program. Results: There were significant differences in dietary quality according to the subject's gender, education level, residential area, spouse or not, family living together or not, subject of meal preparation, calorie requirement recognition or not, exercise practice for diabetes management or not, and depression. Depression and Fasting Blood Sugar management were important influencing factors on dietary quality, and Residence and Gender were also verified as influencing factors. Conclusions: The results of this study can be provided as basic data to establish a program to improve the quality of meals for diabetic elderly patients.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.5
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• pp.357-367
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• 2022

Background: Low-dose dexmedetomidine may be a suitable alternative to opioids for pediatric ambulatory procedures under general anesthesia (GA). However, the recovery profile remains unclear. Herein, we aimed to evaluate the effects of low-dose dexmedetomidine on the recovery profile of children. Methods: Seventy-two children undergoing ambulatory oral rehabilitation under GA were randomly and equally distributed into two groups (D and F). Group D received an infusion of dexmedetomidine 0.25 ㎍/kg for 4 min for induction, followed by maintenance of 0.4 ㎍/kg/h. Group F received an infusion of fentanyl 1 ㎍/kg over 4 min for induction, followed by maintenance at 1 ㎍/kg/h. The primary outcome was the extubation time. The secondary outcomes were awakening time, end-tidal sevoflurane (ET-Sevo) requirement, change in hemodynamic parameters, Richmond Agitation-Sedation Scale (RASS), Children's Hospital of Eastern Ontario pain scale (CHEOPS) score, length of PACU stay, and incidence of adverse events. Results: Statistically significant differences were observed in the recovery profile between the groups: the median time for extubation was 3.65 (3.44-6.2) vs. 6.25 (4.21-7) minutes in groups D vs. F (P=0.001), respectively, while the corresponding awakening times were 19 (18.75-21) and 22.5 (22-24) minutes, respectively (P < 0.001). The mean ET-Sevo was low in group D (1.1 vs. 1.2; P < 0.001). The heart rate was significantly low across all time points in group D, without resulting in bradycardia. The median RASS and CHEOPS scores were also significantly lower in group D. No significant differences were observed in the mean arterial pressure, incidence of adverse events, or length of PACU stay. Conclusion: Low-dose dexmedetomidine was more effective than fentanyl as an opioid substitute at providing a better recovery profile in pediatric ambulatory oral rehabilitation under GA. Dexmedetomidine also significantly reduced sevoflurane consumption without causing adverse events or prolonging hospital stay.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.239-249
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• 2022

This study attempted to categorize the motivation for participation in leisure sports and analyze the difference in consumer demand for leisure sports wear according to the type. As a result of the analysis, the functionality of the preferred material consisted of movement, comfort, and body temperature maintenance. When purchasing, the factors to consider were extracted such as basic emphasis, emphasis on flaunting, and emphasis on practicality. The improvement requirement was composed of basic function improvement and various function additional factors, and the purchase satisfaction factor was composed of three factors: brand, practicality, design, and functionality. Motives for participation in marine leisure sports were grouped into mania, leisure, and health types. As for the functionality of the preferred material, the mania type and leisure type preferred movement, comfort, and body temperature maintenance functionality over the health type. As for the factors to consider when purchasing, the mania type and leisure type had higher consideration for the factors of basic emphasis, ostentation, and practicality than the health type. In the improvement requirements, both basic function improvement and various function additions had the highest mania type and the lowest health type. In terms of purchase satisfaction factors, practicality and brand were found to have a high leisure type, and functional factors were found to have a high mania type. For the enthusiastic group, it is thought that product development should focus on functionality and additional functions, and health types should be focused on design and utilization.