• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.502-510
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• 2021

This study was identified to affection factors the life satisfaction among the college students with allergies by ecological approaches. This study was secondary analysis by using the 2015 Korean Community Health Survey (CHS) raw data, it analyzed 1,862 college students with allergies. Male students' life satisfaction were explained by 7.9% as degree of allergic diseases, frequency of breakfast, networking with friends, social activities with relatives, social activities with religion, satisfaction of natural environment and medical health service. Female students' life satisfaction were explained by 3.0% as frequency of breakfast meal, social activities with relatives and satisfaction of natural environment. We need to make the strategies and policies to improve of student's intake breakfast and make campus' green space.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.501-502
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• 2011

국가R&D정보는 R&D과제, 참여인력, 성과, 장비정보등으로 구성되며, 특히 R&D과제의 참여인력정보를 기반으로 한 의미기반서비스를 위해서는 인력 온톨로지의 모델링이 중요하다. 온톨로지 모델링을 어떻게 하느냐에 따라서 구현 가능한 의미기반서비스의 범위가 달라지며, 구성하는 데이터에 대한 이해도와 서비스 종류에 따라 모델링을 다르게 할 수 있다. 국가R&D인력정보기반 의미기반서비스는 인력정보의 현황과 특성에 대한 이해를 통해 연구자들이 협력대상 연구자와 평가위원 후보를 쉽고 효율적으로 탐색 활용할 수 있는 정보이용환경을 제공하는 것을 목표로 한다. 본 논문에서는 보다 지능화된 의미기반 추론서비스 제공을 위한 국가 R&D 인력정보의 온톨로지 모델링 및 활용 사례를 제시하고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.502-507
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• 2014

In this paper, performance characteristics of cycles were studied when mixed working fluid was used for ocean thermal energy conversion (OTEC). Among the various mixed refrigerants for industrial heat-pump, R32/R152a used in ocean thermal energy conversion system. For simulations, R32/R152a were used in existing closed cycle and Kalina cycle which is used only ammonia and water as mixed refrigerant. Temperature of the warm heat source was 26 and 29 celsius degree, temperature of the cold heat source was 5 celsius degree. In results of simulation, Gross power of the closed cycle on R32 was 22kW, and efficiency of the cycle was 2.02%. When the mixed refrigerant of R32/R152a, in the ratio of 90 to 10, gross power of the closed cycle was 29.93kW, and efficiency of the cycle was 2.78%. Gross power and cycle efficiency of R32/R152a increased by 36% and 37% than those of existing single refrigerant. Additionally, the same simulations were conducted in Kalina cycle with the same various composition ratio of mixed refrigerant.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.615-618
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• 2005

This study concerns the equation of high strength concrete by schmidt hammer test. There are not only few prediction strength equations of concrete by schmidt hammer test, but also many problems to apply them because of time, cost, easiness, structural damage, reliability and so on. For this study, there performed a series of schmidt hammer test with in existing 1,095days' concrete structures and proposed equations as follows ; Linear: ${\Large f}_{ck}=-45.35+2.44R(r^2=72.7\%)$ Quadratic: ${\Large f}_{ck}=-502.08+24.0R-0.25R^2(r^2=82.4\%)$ here, $f_{ck}$ : Estimated compressive strength of concrete by MPa, R : Rebound index of concrete

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.6
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• pp.468-476
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• 2002

This paper deals with heat and mass transfer characteristics and performance evaluation of a counter flow double-tube condenser for a multi-component refrigerant mixture. The local heat and mass transfer characteristics of ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a are evaluated for a counter flow double-tube condenser cooled by water. Then, the local values of vapor quality, thermodynamic states at bulk vapor, vapor-liquid interface and bulk liquid, heat flux and condensation mass flux are obtained. The heat exchange performance for ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a on the total pressure drop and the heat transfer characteristics are also compared with those for R404A, R410A, R502, R22, R32, Rl23 and R134a.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.555-559
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• 2001

This research was conducted to estimate the chlorophyll contents of chrysanthemum leaves using SPAD-502 chlorophyll meter under different photoperiod and light intensity. Measurements were done at every third leaf intervals starting from the top of the stem to the bottom at harvest time. SPAD value was highest at 10 hours of photoperiods, followed by 13 and 16 hours of photoperiods. In particular, under short day condition, SPAD value was highest in the young leaves below the flower bud and decreased down the leaf profile. Under long day condition, SPAD value reached maximum at leaves between $15-27^{th}$ from the top and decreased to the minimum immediately below the flower bud (youngest leaf). These results may indicate that the younger leaves become strong source of supporting flowers in reproductive stage, while the younger leaves serve as sinks and older leaves support their development in vegetative stage. Changes of SPAD value at different levels of irradiance showed that highest SPAD value were observed at high irradiance and decreased with decreasing irradiance.

• Journal of the Korean earth science society
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• v.26 no.7
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• pp.725-731
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• 2005

The distribution and kinematic information of the planetary nebula (PN) may provide a hint about the Galactic dynamics and evolutionary history. An analysis of the Galactic planetary nebular distribution and kinematics (distance, direction, velocity) is underwent, using the 502 PNs observational data given in the ‘THE STRASBOURG-ESO CATALOGUE OF GALACTIC PLANETARY NEBULAE.’ The representative average radial velocities, $(V_r)s$ is derived in six different directions of galactic latitudes, $l = 0^{\circ},\;90{\circ},\;180{\circ},\;270{\circ},$ plus apex and antapex $(56{\circ},\;236{\circ})$, respectively. The PNe near the apex approaches to the Sun with radial velocities, which values are $(V_r) = 69.0 km/s;$ whereas, those near the antapex recedes with $(V_r) = 64.1 km/s$, respectively. No particular trends are found along the z direction, although more PNs are found below the Galactic plane. This implies that the 3rd generation objects, PNs, move slowly on the galactic plane compared to the 4th generation stars like the Sun, indicative of possible interaction.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.502-516
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• 2023

Objectives: The purpose of this study was to investigate occupational exposure to chemical and health status of foreign workers in Korea. Methods: The data were collected from survey of general characteristics, job-related characteristics, work environment-related characteristics of 180 foreign workers who have been working at manufacturing industries in Korea in 2022. The data were analyzed using Rex. Results: Among the 180 participants, men accounted for more than women by 71.7% (129 people). Most of them are Vietnamese or Filipino and most of them graduated from high school. 116 of all participants are exposed to chemicals at work. The most prevalence rate of subject's health problems were backache (61.0%), headache (53.9%), fatigue (68.0%). Controlling for age, the number of physical health problems experienced in the last year was associated with BMI (r=0.184, p=0.049), and the number of mental health problems experienced in the past year (r=0.056, p<0.001) and all showed significant positive (+) correlations. The number of chemical products handled under age control showed a significant negative (-) correlation with working hours (r=0.207, p=0.027) and BMI (r=0.214, p=0.022) and showed a significant positive (+) correlation. Conclusions: The results of this study provided the latest update on the health status of foreign workers in Korea. It is also the first survey to attempt to assess the exposure of foreign workers to chemicals.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.597-617
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• 2012

The purpose of this study was to investigate the current status of Research and Education (R&E) program. The sample included 21 high schools(18 science high schools and 3 gifted high schools) and 1,466 students and 310 mentors. The results are as follows. Total 502 R&E projects were planned and completed. 72.1% of the total research works were guided by professors only, 23.3% were guided by teachers only, and 4.6% were guided by professors and teachers together. Total R&E mentors were 861(385 professors and 476 teachers) and mentees were 2,168. The total budget of 2011 R&E was approximately 4.5 billion won. The needs for program improvement R&E were as follows. 1) When selecting R&E topics, mentors need to consider students' current knowledge level and school curriculum. 2) Mentors should provide enough opportunities to master topic-related basic knowledge. 3) The performance should be monitored periodically. 4) The support for continuous research and improvement of research environment were requested.

• Journal of Life Science
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• v.21 no.4
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• pp.502-508
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• 2011

The purpose of this study was to evaluate the methods of identifying zygotic seedlings of crosses between 'Morita unshiu' (Citrus. unshiu Marc.) and 'Ponkan' (C. reticulata Blanco). In order to investigate the frequency and position of zygotic seedlings and to determine the efficiency of zygotic seedling identification, random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) were performed using UBC (9, 27, 229, 230, and 254) primers and F4/R27, F7/R14, F12/R10, and F44/R62 primer sets, respectively. A total of 37 putative zygotic seedlings out of 55 individuals were selected by RAPD and SRAP. The F7/R14 primer pair showed a screening ability of 45.5% (25/55), whereas the primer UBC27 revealed the highest efficiency of zygotic seedling identification (50.9%, 28/55). When both UBC27 and F7/R14 were properly used for selection of hybridized seedlings of 'Morita unshiu' (C. unshiu Marc.) and 'Ponkan' (C. reticulata Blanco), screening efficiency was increased to 60% (33/55) for putative zygotic seedlings. Thus, it is possible to select putative hybrid zygotic seedlings in an accurate and effective manner by RAPD and SRAP.