• Journal of the Korean Society for Library and Information Science
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• v.57 no.3
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• pp.97-117
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• 2023

The purpose of this study is to suggest a mid- to long-term expansion plan to resolve the blind spot and alleviate the imbalance of public library services in Daegu City. The research methods for this purpose included literature review, related laws and statistical data analysis, case study, and opinion survey. As a result, the first service area was set as a total of 14 areas based on administrative districts(Jung-gu, Seo-gu, Nam-gu, and Dalseong-gun each have one, Dong-gu and Buk-gu each have two, and Suseong-gu and Dalseo-gu have three each). Second, the expansion scenario for public libraries in Daegu City was proposed to add 26 libraries by the final target year (2032) based on the trend of national library growth over the past 13 years (2008-2020) and the forecast for the next 10 years (2023-2032). Third, the construction scenarios for each basic local government, excluding the Daegu representative library, are as follows: One library each in Jung-gu, Seo-gu, and Nam-gu; two libraries in Suseong-gu; three libraries in Dalseong-gun; four libraries in Dong-gu; and seven libraries each in Buk-gu and Dalseo-gu. In terms of floor area, it is proposed to add a total of 17 branch libraries with a minimum legal standard of 330-2,499㎡, four central libraries with 2,500-4,999㎡ each, and four central libraries with 5,000-9,999㎡ each. On the premise of these conditions, Daegu City and public libraries should focus on creating an inclusive and open community space, creating a digital platform, strengthening the library operation and cooperation system centered on Daegu representative library, developing collections and specializing services for local hub libraries, enhancing various knowledge information and program services, managing key library indicators and improving social contribution.

• Journal of Platform Technology
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• v.10 no.4
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• pp.3-10
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• 2022

In this study, damage resulting from internal flaws was investigated by finite element analysis for the safety evaluation of a non-destructive testing platform for hydrogen pressure vessels. A specimen was modeled and calculated using finite element analysis to determine material properties in accordance with the parameters of the composite material in order to assess the safety of the Type 4 hydrogen pressure vessel. Through this, flaws in the hydrogen pressure vessel were modeled, and test conditions were provided in accordance with rules to look into whether there was safety. Delamination, foreign object, and vertical cracks were modeled for internal flaws, and damage was examined in accordance with failure criteria. As the delamination defect approached the interior of the hydrogen pressure tank, it became more likely to cause damage. Additionally, as the crack depth grew in the case of vertical cracks, the likelihood of crack propagation rose. On the other hand, it was anticipated that the foreign item defect would suffer more damage from the outside in. A non-destructive testing platform will be used to assess the safety of fuel cell vehicles that are already in operation in future research.

• Journal of Korea Water Resources Association
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• v.56 no.9
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• pp.587-602
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• 2023

Due to climate change, population growth, and economic development, the demand for water in the urban water system (UWS) and the energy required for water use constantly increase. Therefore, beyond the traditional method of considering only the water sector, the Nexus approach, which considers synergies and trade-offs between the water and energy sectors, has begun to draw attention. In previous researches, the Nexus methodology was used to demonstrate that the UWS is an energy-intensive system, analyze the water-energy efficiency relationship surrogated by energy intensity, and identify climate (long-term climate change, drought, type), geographic characteristics (topography, flat ratio, location), system characteristics (total supply water amount, population density, pipeline length), and operational management level (water network pressure, leakage rate, water saving) effects on the UWS. Through this, it was possible to suggest the direction of policies and institutions to UWS managers. However, there was a limit to establishing and implementing specific action plans. This study built the energy intensity matrix of the UWS, quantified the impact of city conditions, external influences, and operational management levels on the UWS using the water-energy Nexus model, and introduced water-energy efficiency criteria. With this, UWS managers will be able to derive strategies and action plans for efficient operation management of the UWS and evaluate suitability and validity after implementation.

• Clean Technology
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• v.16 no.4
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• pp.277-283
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• 2010

Eosin Y is used a colorant and dye but eosin Y is harmful toxic substance. In this study, the adsorption characteristics of granular activated carbon have been investigated for the adsorption of eosin dye dissolved in water. The effects of initial dye concentration, contact time, pH and temperature on adsorption of eosin by a fixed amount of activated carbon have been studied in batch adsorber and fixed bed. The adsorptivity of activated carbon for eosin Y were largely improved by pH control. When the pH was 3 in the sample, the eosin Y could be removed 99% of initial concentration (10 mg/L). The adsorption equilibrium data are successfully fitted to the Freundlich isotherm equation in the temperature range from 293 to 333 K. The estimated values of k and ${\beta}$ are 19.56-134.62, 0.442-0.678, respectively. The effects of the operation conditions of the fixed bed on the breakthrough curve were investigated. When the inlet eosin Y concentration is increased from 10 to 30 mg/L, the corresponding adsorption breaktime appears to decrease from 470 to 268 min at bed height of 3 cm and a constant flow rate of 2 g/min. When the initial eosin Y flow rate is increased from 1 to 3 g/min, the corresponding adsorption breaktime appears to decrease from 272 to 140 min at bed height of 3 cm and inlet concentration of 10 mg/L. Also, breaktime increased with increasing bed height at flow rate of 2 g/min and inlet concentration of 10 mg/L. And length of adsorption zone showed similar patterns.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.217-229
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• 2023

Forest projects often apply construction industry labor rates, without considering the demanding work conditions and labor intensity unique to forest operations, resulting in workplace issues. This study aims to analyze forest operations' characteristics and wage survey methods in other fields to establish a framework for surveying the wages of forest workers. The developed framework was tested through direct surveys conducted with all forest operation companies. Survey items included actual wages by occupation, identification and removal of outliers using quartile deviation, and occupation-based wage calculation. Results revealed that the appropriate wages for 2022 were as follows: KRW 163,376 for general workers, KRW 221,407 for special workers, KRW 250,045 for work leaders, and KRW 239,863 for wood cutters. These figures were 16.27% higher than those derived from the standard construction wage survey. The developed framework was validated by comparing the appropriate wages with both the standard construction wage survey and the forestry workers' wage. The results indicated that the wages calculated using the developed framework were 4.5% more similar to the forestry workers' wage compared with those from the standard construction wage survey. Consequently, the standard construction wage survey was deemed unsuitable for forest projects. To ensure efficient forest operations, it is imperative to conduct wage surveys using the developed framework over multiple years to accumulate sufficient data.

• Journal of the Korea Convergence Society
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• v.13 no.1
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• pp.89-99
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• 2022

Due to COVID-19, non-face-to-face cultures such as remote classes, remote work, and tele-medicine are spreading. The major contributors to the settlement of such a non-face-to-face society are small and medium SW companies and SW manpower. However, recently as large platform companies and foreign big tech companies hire thousands of SW manpower, SW small and medium-sized companies are experiencing a serious manpower shortage. Therefore, the purpose of this study is to suggest policy alternatives for SMEs to stably secure SW manpower and support continuous business operation. To achieve this purpose, this study examines the current status of the SW industry and manpower, then summarizes related issues and suggests policy alternatives to solve these issues. Those policies include the reinforcement of incentives to support manpower retention such as the Naeil Chaeum deduction system, youth housing union composition, special military service system, recruitment of manpower through the contract semester system of employment conditions, reinforcement of customized education through supplementation of the SW manpower training voucher system, SW field skill standardization, establishment of a governance system for nurturing SW manpower, preparation of countermeasures against the outflow of manpower to large companies, and a win-win cooperation program for large and SME SW manpower.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.243-249
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• 2023

The occurrence of cavitation on the propeller is directly linked to the naval ship's survivability, and it is necessary to design a propeller shape that delays the cavitation inception. However, the propeller cavitation can occur under various operating conditions, thus it is important to identify whether the propeller cavitation exists during operation as well as in the design phase. To this end, it is necessary to use noise or vibration signals on board to monitor the cavitation inception. In this study, a hydrophone and an accelerometer were installed on the ship hull right above the propeller to compare the performance of analyzing cavitation inception between acoustic and vibration signals. Also, a high speed camera was used to visually observe the occurrence of cavitation through an observation window. The measured results showed that the spectral shapes between acoustic and vibration signals were different, but the level increases at each frequency band and the overall level of the frequency band from 1 kHz to 10 kHz showed a similar tendency. The Detection of Envelope Modulation On Noise (DEMON) analysis also showed similar results for both acoustic and vibration signals, confirming that both hydrophones and accelerometers can be utilized in the analysis of cavitation inception.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.175-185
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• 2016

In this study, manufactured experimental pig house (two pig house) and compared the changes in internal temperature and energy depending on the application of UTC control system for their utilizing of them as basic data for maintaining proper conditions for feeding environment and reducing heating energy depending on the UTC control system and program development, prior to applying the UTC system into pig house, representative agricultural facility. The control system ranges T1~T4 which is made to control a total of five output signals O1~O5 in the way of On/Off by using the algorithms of the program after measuring temperature scored 4 of total. Temperature setting was controlled with 28.0℃ in experimental pig house and 34.0℃ in UTC plenum, and output signal was controlled by comparing it with the measured temperature. During 3 days, the maximum temperature were measured at an average 31.8℃ when operated the control system in pig house. At the same time, the maximum temperature were measured 36.6℃ in comparison pig house, it was low temperature at 4.8℃ in experimental pig house than comparison pig house. Also, UTC plenum temperature was showed that rose at an average 50.5℃ by operation of the control program.

• Journal of the Korean Institute of Gas
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• v.27 no.2
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• pp.1-6
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• 2023

PE piping, which has advantages in terms of construction convenience and economy, is widely used for underground burial in the domestic urban gas field. These PE pipes use squeeze-off in many sites to block gas flow during maintenance and repair work. Squeeze-off refers to a method of compressing a PE pipe to block fluid flow, and damage may occur due to the nature of construction in which the pipe is deformed by physical force. In order to prevent damage to PE pipes due to squeeze-off, the main points to be reflected in the squeeze-off operation procedures such as proper compression range, use pressure, and diameter were derived through damage assessment and confidential test according to the compression rate. The compression experiment for PE pipe damage assessment was conducted while changing the compression rate (20%~40%), the pressure of use (2.8 kPa, 25 kPa, 70 kPa), and the pipe diameters (63 mm, 90 mm, 110 mm). As a result of damage assessment according to the compression rate, damage occurred in pipes with compression rates of 45%(110mm) and 73%(63mm), which are for analyzing the effect of excessive compression. In addition, the leakage test was conducted using Ar(argon) during the squeeze-off, and as a result of the experiment, leakage occurred under the conditions of 70kPa and 110mm of pipe. As a result of this study, it was confirmed that squeeze-off for airtightness should be carried out in pipes within a range not exceeding 25 kPa and 90 mm pipes, and the appropriate compression rate to prevent damage to PE pipes is 30%.

• Journal of Service Research and Studies
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• v.11 no.3
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• pp.75-97
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• 2021

This study was conducted to derive a society and education system model that will improve the happiness and sustainability of human society. An ideological model for making human society a happy society was derived, and a society and education system structure and operation model based on this was presented. A fair society, a justice society, a mutually considerate society, and a society where individuals are happy are the conditions for a sustainable society. After analyzing the current situation of freedom and equality pursued by capitalism and democracy, which are currently adopted by most societies, an improvement model was derived from the perspective of a sustainable society. The cost of freedom and equality were analyzed and a new alternative system was discussed. The social solidarity and class mobility issues were discussed together and servicism was derived as an alternative solution. It is a system in which two opposing opponents of individual freedom and social norms form a symmetrical balance, and material and spiritual values are balanced. Servicism is a dynamic balance model. That is, the dimensions of time and space are involved. It is a model that maintains a thorough balance through a dialectical process as time and space change, and one value can dominate the other at a specific time or space. The service-oriented society and education system is a system that simultaneously pursues the goals of individual happiness and sustainable development of the social community.