• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.623-628
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• 2009

Desiccant based air conditioning system offers a promising alternative to conventional one using vapour compression refrigeration for energy saving and greenhouse gas reduction. It is a heat driven cycle which has high potential for the use of low grade heat source such as the waste heat from the cogeneration plant or the solar thermal energy. In this study, the cooling performance of a desiccant cooling system incorporating a regenerative evaporative cooler was characterized in various operation conditions through numerical simulation. The cooling capacity and COP were evaluated at various outdoor conditions, regeneration temperatures, and supply flow rates. Based on the performance characteristics, the optimal control scheme was discussed to minimize the cooling cost at part load condition.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.5
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• pp.490-496
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• 2018

Recently, the power and refrigeration cogeneration based on Kalina cycle has attracted much attention for more efficient utilization of low-grade energy. This study presents a thermodynamic performance analysis of a cogeneration cycle of power and absorption refrigeration based on Kalina cycle. The cycle combines Kalina cycle (KCS-11) and absorption cycles by adding a condenser and an evaporator between turbine and absorber. The effects of ammonia mass fraction and separation pressure were investigated on the system performance of the system. Results showed that the energy utilization of the system could be greatly improved compared to the basic Kalina cycle.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1969-1974
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• 2004

The performance of small cyclone is analysed by an experiment for the purpose of developing a bag-less vacuum cleaner. For the high collection efficiency and low pressure loss cyclone, the effect of cyclone inlet feature must be well understood. Four types of the helical inlet are considered to compare with the normal tangential inlet, and also various inlet velocities are used to each inlet type. Based on the reference dimension, each type of inlet shows the changes of the grade efficiency and pressure loss which determine the cyclone quality. The results show that the helical inlet has the smaller cut-size but bigger pressure loss than the tangential inlet. And the degree of opening area influences factors of cyclone performance. As the inlet velocity is increased, the cut-size becomes smaller and the pressure loss becomes bigger of each cyclone. Further studies are required to understand the optimized helical inlet of cyclone.

• Journal of the Society of Disaster Information
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• v.6 no.1
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• pp.10-24
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• 2010

In this paper, warm asphalt binder was proposed as a substitute for the polymer-modified asphalt binder to get higher viscosity than that of the polymer-modified at the same temperature. Performance grade test and rotational viscosity of warm asphalt binder were conducted to evaluate the property variations due to the addition of admixture. Research results showed that the viscosity of warm asphalt binder at $100^{\circ}C$ was similar to that of the conventional asphalt binder. The performance and durability of warm asphalt binder were also comparable to those of the polymer-modified. It is considered that the active applications of warm asphalt binder can reduce environmental damages due to less diffusions of carbon dioxide compared to the conventional.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.2
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• pp.179-187
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• 2024

The performance of a Strapdown Inertial Navigation System (SDINS) relies heavily on the accuracy of sensor error calibration. Systematic calibration is usually employed when only a 2-axis turntable is available. For systematic calibration, the body frame is commonly defined with respect to sensor axes for ease of computation. The drawback of this approach is that sensor axes may undergo time-varying deflection under temperature change, causing pseudo gyro bias. The effect of pseudo gyro bias on navigation performance is negligible for low grade navigation systems. However, for higher grade systems undergoing rapid temperature change, the error is no longer negligible. This paper describes in detail conditions leading to the presence of pseudo gyro bias, and proposes two techniques for mitigating the error. Experimental results show that applying these techniques improves navigation performance for precision SDINS, especially under rapid temperature change.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3461-3464
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• 2014

Background: To determine the frequency of dysplastic lesions in the endocervical curettage (ECC) specimens of women with ASC-US and LSIL Pap and to evaluate the possible factors associated with high grade dysplasia in those ECC specimens. Materials and Methods: Two hundred and sixty patients with ASC-US and LSIL cytologic smears who underwent an ECC at the time of colposcopic examination during January 2010 and December 2012 were reviewed. Demographic and clinicopathologic data were collected. Multivariate analysis using binary logistic regression was used to identify factors that might be associated with high grade endocervical dysplasia. Results: The frequency of endocervical dysplasia was 7.7% (20 out of 260 patients). Cervical intraepithelial neoplasia (CIN) 1 and CIN 2-3 lesions in the endocervical canal were observed in 12 and 8 patients, respectively. No microinvasive or invasive cervical cancers were identified. There was no difference in the frequency of high grade endocervical dysplasia between the patients with satisfactory and unsatisfactory colposcopic examinations (1.4% vs 5.1%, respectively, p=0.087). A multivariate logistic regression analysis demonstrated a significant association between high grade CIN on ectocervical biopsy as well as LSIL cytologic smears and high grade dysplasia in endocervical canal (OR=0.046, 95%CI=0.007-0.288; p=0.001 and OR=0.154, 95%CI=0.025-0.942; p=0.043, respectively). Conclusions: The frequency of high grade endocervical dysplasia in women with ASC-US and LSIL cytologic smears was low. Therefore, routine performance of ECC in those women is debatable. High grade ectocervical dysplasia and LSIL cytologic smears may be used as predictors for high grade dysplasia in endocervical canal and ECC in these patients is reasonable.

• KIEAE Journal
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• v.11 no.6
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• pp.29-35
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• 2011

This study aims to suggest improvement plans and explain about the current situation for facilitating Long-life housing, based on the results on flexibility items among 27 items consisting the "Housing Performance Grading System". From the 9th of January, 2006 to the month of July in 2011, study has analyzed evaluation results on 216 different types for each grade and reviewed evaluation criteria and methods. Current evaluation criteria applies quantitative analysis, by calculating in percentage how much bearing walls and columns, which hinder flexibility, take up space in the household. The evaluation rate for each household was assessed in relation to its structural system, and a higher grade was given to column-typed structures. In addition, to facilitate long-life housing, this study extracted harmful factors, expanding the range of evaluation. The first step was to evaluate structure, which is the basic element. The second step can to evaluate the probability of applying resources in response to the changes of structural systems. As The third step, Flexibility item will evaluate the probability of moving the water-using area, suggesting gradual approach. Thus, through evaluations of flexibility items, the study aims to improve the quality of life in household, by avoiding uniform structures and acquiring more freedom for space designs.

• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.32-39
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• 2020

The fire compartments with fire-resistant construction are installed in the principal structural parts of a building in order to reduce damage in the event of a building fire. As a fire may spread through a crack in the fire compartment, the firestop with secured performance is used according to the procedure, methods, and standards specified in the detailed operation guideline. According to the current detailed operation guideline, vertical members (wall penetration) and horizontal members (floor penetration) are classified into different categories respective to each other for the classification of the firestop. Therefore, an accreditation applicant must apply for the performance test for each structure even if the wall and the floor have the same structure. Also, Grade T is used for the firestop that penetrates the fire compartment. However, in the case of foreign countries, the use of Grade F for the firestop is allowed even if it penetrates the fire compartment. The result of the precedent studies also showed that there was a significantly low possibility of fire to spread even if Grade F was applied for a metallic duct that penetrated the fire compartment. In this study, the improved scheme for the classification and performance standard of firestops was presented by analyzing the results of precedent studies regarding the firestop and domestic and overseas firestop qualification systems.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.471-478
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• 2021

The purpose of this study were to investigate knowledge, awareness, performance, and preventive behavior of latent tuberculosis infection management, and to identify influencing factors on preventive behavior of latent tuberculosis infection management of nursing students. The subjects of this study were completed by 191 nursing students from 2 colleges in D City. Data were collected from August 1 to November 30, 2020. Data were analyzed using the t-test, the ANOVA, the Pearson correlation coefficient, and stepwise multiple regression analysis by SPSS ver. 21.0. There were significant positive correlations between preventive behavior of latent tuberculosis infection management and performance(r=.21, p=.003), awareness and performance(r=.88, p<.001). The factors influencing grade and education experience about latent tuberculosis infection management of the study subjects were grade(β=.29, p<.001), final time of education experience about tuberculosis(β=.19, p=.004), and the explanatory power of these variables was 11.9%. The development of preventive behavior of latent tuberculosis infection management education program that focuses grade and final time of education experience about tuberculosis is needed.

• Journal of the Korean Professional Engineers Association
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• v.42 no.4
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• pp.68-74
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• 2009