• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.51-56
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• 2012

This paper reports the generation efficiency and the thermal performance of a thermoelectric generator (TEG) harvesting energy from the waste heat of high power electronic components. A thermoelectric (TE) model containing thermal boundary resistances is used to predict generation efficiency and junction temperature of a high power electronic component. The predicted results are verified with measured values, and the discrepancy between prediction and measurement is seen to be moderate. The verified TE model predicts generation efficiencies, junction temperatures of the component, and temperature differences across a TEG at various source heat flows associated with various electrical load resistances. This study explores effects of the load resistance on the generation efficiency, the temperature difference across a TEG, and the junction temperature.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.9-15
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• 2023

The task of generating a reduced thermal model of a satellite must be performed at least once in a satellite project to shorten the time of orbital thermal analysis and perform thermal analysis coupled to a launch vehicle. Although there are various methods for generating a reduced thermal model, an intuitive and convenient iso-thermal mesh generation method is used the most widely in practice. However, there is still a lack of research on automation of the isothermal mesh generation method. In this paper, we proposed an automated generation method of satellite reduced thermo-mathematical model based on the isothermal mesh generation method considering temperature tolerance and fixed nodes. The proposed method was validated using three different temperature tolerance cases. The average temperature difference satisfied the guidelines of ECSS.

• Journal of Environmental Science International
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• v.25 no.10
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• pp.1369-1379
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• 2016

This research assessed the disparity in anion generation according to the vertical structure of a Zelkova Serrata tree for the purpose of creating a pleasant and green city environment. Measurements for the study were conducted between July and August of 2014 in Chung-ju in the central region of the Republic of Korea. The average anion generation of vertical structure trees during active photosynthesis periods was: L Section ($839.0ea/cm^3$) > M Section ($664.6ea/cm^3$) > U Section ($472.0ea/cm^3$). According to DMRT analysis, significant difference was found in the average between the L, or M Locations and the U Locations. During dormant photosynthesis periods, records showed that the anion production at the M Location ($1,212.5ea/cm^3$) > L Location ($1,050.4ea/cm^3$) > H Location ($844.1ea/cm^3$), According to DMRT analysis, the difference within each location was significant for ${\alpha}=0.05$. In a comprehensive analysis of the weather factors in each vertical structure, anion generation during active photosynthesis periods showed a positive correlation with solar radiation and a negative correlation with wind speed. Dormant photosynthesis periods showed negative correlations with both solar radiation and temperature, and positive correlations with relative humidity and wind speed. Predictions from a multicenter retrospective study showed that during active photosynthesis periods, $Y_1=282.443X_1+512.07$, and $Y_2=314.337X_1+16.913X_2$, while during dormant photosynthesis periods, $Y_1=391.009X_1+840.043$, and $Y_2=351.412X_1+32.765X_2$.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.210-215
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• 2002

In respect of global environment protection and efficient utilization of energy, co-generation systems, which have greatly higher efficiency than the other generations, have been developed and put to practical use. Assuming that the co-generation system would be operating in Park Hotel, this paper calculates the difference between the heat and electricity rates by the conventional method and the co-generation system, considers the cost of new investment and analyzes introduction economics based on the return on investment. The introduction is turned out to be recommendable, since the return of investment for co-gen oration equipment is about ten years when the co-generation profits in heat and electricity rate. Additionally, accounting for interest rate drop, improvement of environmental matters or electricity rate increase, it is shown to be even more economical.

• Journal of Periodontal and Implant Science
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• v.52 no.5
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• pp.411-421
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• 2022

Purpose: In this study, we aimed to evaluate the degree of heat generation when a novel drill design with an irrigation slot was used with metal sleeve-free (MF) and metal sleeve-incorporated (MI) surgical guides in an environment similar to that of the actual oral cavity. Methods: A typodont with a missing mandibular right first molar and 21 bovine rib blocks were used. Three-dimensional-printed MF and MI surgical guides, designed for the placement of internal tapered implant fixtures, were used with slot and non-slot drills. The following groups were compared: group 1, MI surgical guide with slot drill; group 2, MI surgical guide with a non-slot drill; and group 3, MF surgical guide with a slot drill. A constant-temperature water bath at 36℃ was used. The drilling was performed in 6 stages, and the initial, highest, and lowest temperatures of the cortical bone were measured at each stage using a non-contact infrared thermometer. Results: There were no temperature increases above the initial temperature in any drilling procedure. The only significant difference between the non-slot and slot groups was observed with the use of the first drill in the MI group, with a higher temperature in the non-slot group (P=0.012). When the heat generation during the first and the second drilling was compared in the non-slot group, the heat generation during the first drilling was significantly higher (P<0.001), and there was no significant difference in heat generation between the drills in the slot group. Conclusions: Within the limitations of this study, implant-site preparation with the surgical guide showed no critical increase in the temperature of the cortical bone, regardless of whether there was a slot in the drill. In particular, the slotted drill had a cooling effect during the initial drilling.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.3
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• pp.335-361
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• 2018

This study aims at exploring the Eco-generation's perception on public libraries depending on the use of cultural programs. For this purpose, a series of in-depth interviews was conducted with public library users in the Eco-generation in order to investigated the current status of the cultural programs in public libraries and their underlying identity. The results identifies that user experience of library cultural programs did not make a meaningful difference in users' perceptions on public libraries. Furthermore, there was no meaningful difference in the perceptions on cultural programs between public libraries and other cultural organizations. A possible explaining factor to the results based on the interviews and existing research reports was identified as the lack of identity in the library cultural programs. Consequently, further studies on public libraries' identity, cooperation between research and practice in public libraries, discussion with cultural organizations in the library district, and considerations in public policy are suggested in order to strengthen the identity in the library cultural programs.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.66-73
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• 2008

In this study, the characterization of minor livestock's excretions in terms of unit load generation and discharge was conducted by investigation and analysis of urine, manure and wastewater from stall of fowl, duck, horse, deer, goat and sheep. The results are summarized as follows: The unit load generation of fowl estimated by discharged amount and concentration analysis increases in egg layers due to the difference of planting head numbers, feed stuffs and manure disposal. In case of deer unit load generation by herbivora were calculated to be higher than data from existing references because of the gap between weight per livestock and the generation amounts of manure and urine. In case of sheep unit load generation by urine were analyzed two times higher than by manure but unit load generation by manure were reported higher than by urine in references, so large differences between this and previous study resulted.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4D
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• pp.451-457
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• 2009

This study verifies parking requirements of an apartment suggested in parking generation law in Korea through analysing the surveyed parking generation rate. It is revealed that the parking requirements according to the gross floor area in parking generation law is similar to the surveyed parking generation rate as an average but the differences of each requirements by region and apartment's size are not significant. Parking generation rate results in strong correlation with the number of household rather than the gross floor area, and the new requirements suggested in this study, based on the number of household, shows significant difference by region and apartment's size, which is consistent with common sense. This study suggests parking requirements of an apartment, based on the number of household, by region and apartment's size for 6 groups. Surveyed parking generation rate of each group is fitted to statistical distribution and the mean value of fitted statistical distribution is suggested as the parking requirements of each group. Parking requirements based on the number of household is easily recognized of its relative and absolute value, and moreover is consistent with the surveyed parking generation rate.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.459-468
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• 2016

This study analyzed in depth the students' health fitness trend characteristics based on the per generation characteristics longitudinal grade level document that was produced by collecting heath fitness measurements of students from all over the country for the purpose of exploring the appropriate wellness management plan. The following conclusion was derived through the collected materials and results according to the research purpose and method. First, it was determined that muscular endurance trends for both boys and girls in their elementary school period were similar for the current generation and the previous one, but as they went through their middle school period their muscular endurance development levels were found to be reduced compared with the previous generation students. Second, there was no difference in the cardiorespiratory endurance trends between the current and the previous generation students, unlike all other physical factors. Third, the boys displayed deteriorated reflex development during their growth period compared with their previous generation counterparts. On the other hand, girls displayed mostly stagnant development once they reached 8th grade level within their generation.

• Journal of the Korean Society of Combustion
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• v.18 no.3
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• pp.1-8
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• 2013

Thermodynamic and economic analyses of various types of gas turbine combined cycle power plants have been performed to establish criteria for optimization of power plants. The concept of efficiency, in terms of the difference in energy levels of electricity and heat, was introduced. The efficiency of power and heat generation by power plants with other purposes was estimated, and power generation costs were figured out for various types of combined heat and power plants(i.e., fired and unfired, condensing and non-condensing modes, single or double pressure HRSG).