• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.4
• /
• pp.197-205
• /
• 2022

In this paper, a retaining wall system, developed using building Information modeling (BIM), is presented. Based on the information from a literature review, elementary technologies for the system were defined and developed. First, for the elementary technology, BIM libraries were constructed using standards and previous study results to achieve versatility and reusability. Second, methods for determining the quantity take-off (QTO) of a retaining wall were reviewed for an earth-work calculating system. Additionally, inverse distance weighting interpolation was used to generate topography. Finally, four formulas for calculating the QTO were proposed and devised for each element. After its development, the BIM system was analyzed and verified through comparison with a two-dimensional drawing-based QTO. The proposed system is deemed to be practical for determining the QTO of retaining walls and earth works. The contributions and limitations of the research are discussed in this paper.

• Korean Chemical Engineering Research
• /
• v.61 no.2
• /
• pp.278-286
• /
• 2023

The present work evaluated the production of biohydrogen under mesophilic and thermophilic conditions through dark fermentation of palm oil mill effluent (POME) in batch mode using the design of experiment methodology. Response surface methodology (RSM) was applied to investigate the influence of the two significant parameters, POME concentration as substrate (5, 12.5, and 20 g/l), and volumetric substrate to inoculum ratio (1:1, 1:1.5, and 1:2, v/v.%), with inoculum concentration of 14.3 g VSS/l. All the experiments were analyzed at 37 ℃ and 55 ℃ at an incubation time of 24 h. The highest chemical oxygen demand (COD) removal, hydrogen content (H₂%), and hydrogen yield (HY) at a substrate concentration of 12.5 g COD/l and S:I ratio of 1:1.5 in mesophilic and thermophilic conditions were obtained (27.3, 24.2%), (57.92, 66.24%), and (6.43, 12.27 ml H₂/g COD_rem), respectively. The results show that thermophilic temperature in terms of COD removal was more effective for higher COD concentrations than for lower concentrations. Optimum parameters projected by RSM with S:I ratio of 1:1.6 and POME concentration of 14.3 g COD/l showed higher results in both temperatures. It is recognized how RSM and optimization processes can predict and affect the process performance under different operational conditions.

• Journal of Christian Education in Korea
• /
• v.73
• /
• pp.39-54
• /
• 2023

In this study I want to explore faith formation through the framework of practice. First, I will describe discipleship as a lifelong process of identity formation, defining Christian religious education as a faith community's intentional work of equipping people to walk in the way of Jesus through apprenticeship in faith practices. I will argue that this process is more about the teaching of practices and engaging in theological reflection on practices than it is about dispensing correct information. This idea is not original with me, but has been expounded by many others particularly in the past decade in the U.S., as part of a larger movement within theological discourse emphasizing the centrality of practice. Second, I will describe some resources from educational theorists that can help us to understand what it means to educate through practices toward an identity as Christians. And finally, I will suggest that in our complex, broken and wounded world, as Christian religious educators we especially have a calling to equip disciples in two urgent faith practices: earth-care, and dealing with conflict.

• The Journal of the Acoustical Society of Korea
• /
• v.29 no.2
• /
• pp.111-117
• /
• 2010

Sonoluminescence (SL) is the light emitting phenomenon accompanied with ultrasonic cavitation in liquid. It attracts many interests because physics behind it remains uncertain and few applications have appeared. It has been known that the color of SL changes in solutions which include metallic ions. In the present work, colors of SL in alkali metallic and alkaline earth metallic ions were considered. RGB component was used to analyze the color of SL. By using RGB component, it was found that color of SL in metallic solution can be resolved into color of SL in pure water and flame color of metal which is different from high intensity color of line spectrum of alkaline earth metal. From this result, influence of metallic ion on SL and the temperature on violent collapsing of cavitation bubble was discussed.

• Journal of Environmental Health Sciences
• /
• v.42 no.2
• /
• pp.92-101
• /
• 2016

Objectives: Outdoor workers are exposed to thermally stressful work environments. In this study, heat stress indices for harbor workers in summer were calculated to evaluate thermal comfort based on a human heat balance model. These indices are Physiological Subjective Temperature (PST), Dehydration Risk (DhR), and Overheating Risk (OhR) according to respective stage of cargo work in a harbor. In addition, we constructed a forecast system to provide heat stress information. Methods: Thermophysiological indices in this study were calculated using the MENEX model (i.e. the human heat balance model), which used as inputs the meteorological parameters, clothing insulation, and metabolic rate for each stage of cargo work in the harbor of Masan over the course of seven days, including a four-day heat wave. The forecast heat stress information constructed for Masan harbor was based on meteorological data supported by the Dong-Nae Forecast from the KMA (Korea Metrological Administration) and other input parameters. Results: According to higher metabolic rate, thermophysiological indices showed a critical level. In particular, PST was evaluated as reaching the 'Very hot' or 'Hot' level during all seven days, despite the heat occurring over only four. It is important in a regard to consider the work environment conditions (i.e. labor intensity and clothing in harbor). On a webpage, the forecast thermophysiological indices show as infographics to be easily understand. This webpage is comprised of indices for both current conditions and the forecast, with brief guidance. Conclusion: Thermophysiological indices show the risk level to health during a heat wave period. Heat stress information could help to protect the health of harbor workers. Further, this study could extend the applicability of these indices to a variety of outdoor workers in consideration of work environments.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.11 no.5
• /
• pp.44-52
• /
• 1997

Electronic circuits with semiconductor and IC are very weak against the surge voltage and currents. The surge protective devices for electronic circuit and AC power lines are becoming more widely used. It is possible to give rise to the malfunction of the earth leakage circuit breaker(ELB) due to the operation of surge protective devices, and the interruption of AC power lines on account of the malfunction of the ELB brings about several disadvantages such as low operation efficiency and reliability of electronic and informational systems, economical loss, and etc. The aim of the present work is to investigate the dead operation characteristics of the ELB against the surge voltages. The impulse generator of 10[kV) in an 1.2/ 50[~) voltage waveform was fabricated. The dead operation characteristics of the ELB applied by surge voltages were measured under the conditions of KS C 4613 and the test circuit with a varistor. As a consequence, the peak value of the zero-phase sequence circuit of the ELB is increased as the surge voltage and stray capacitance increase. All of the ELBs used in this work were satisfied with the lightning impulse dead operation test condition defined in KS C 4613. However one specimen only did not bring about dead operation in the condition of the test circuit with a varistor. There is high possibility that a large portion of the ELB installed at the AC power lines with the surge protective devices bring about the dead operation.

• Journal of Korean Society for Geospatial Information Science
• /
• v.11 no.1 s.24
• /
• pp.21-28
• /
• 2003

This study was aimed at suggest a proper planning method to select a optimal forest road network in mountains forest using GIS(Geographic Information System). To examine the field applicability, the method was applied to the National Forest at Mt. Kumsan in Namhae-gun, Gyungsangnam-do. The main results from altogether six alternative road route plans were derived from these criteria obtained the alternative route plan No.2 has two layout criteria, longitudinal gradient and earth work volume, and it showed similar pattern of existing forest road network which was designed mainly ground slope and longitudinal gradient. The alternative route plan No.6 has four criteria, longitudinal gradient, earth work volume, investment effect and landscape impact. It was different for the lowest forest road density among the alternatives and the pattern of the forest road layout was radial form, which was also quite different to other alternatives. For optimal forest road network planning, GIS provide the efficient and resonable solutions for decision making to provide the support for evaluation about various alternative road networks. If detailed inventory and relevant data are provided and also clear and objective indicators for evaluations are set up, it could be applied to preliminary analysis and detail planning stage to prevent undesirable effect such the land slide and soil erosion due to inadequate planning for forest road network.

• Economic and Environmental Geology
• /
• v.53 no.1
• /
• pp.45-69
• /
• 2020

In Danyang area, various geological structures as well as various lithology and strata are well developed, which are useful for studying paleo-environment and structural movements, and also typical karst landforms, wethering landforms and river landforms. If geologically and geomorphologically valuable resources are used in terms of geotourim perspective, it is expected that revitalization of regional economy through diversification of attracting factors and employment creation of local people. Danyang has many excellent geological resources for geological field trip, they can greatly contribute to the development of geology such as expanding the base of geology and cultivating successive generations. In this study, we have evaluated newly discovered sites and previously excavated resources based on academical and educational values. By using these geological and geomorphological resources, we suggest three geotrail courses as follows. First, Geo-trail A is mainly focused on geological structures (Route A: Jeong Hwan Route), where we can learn geological deformation and movement through various brittle and ductile deformation structures. Second, Geo-trail B is mainly focused on stratigraphic importance (Route B: Soon-Bok Route), which emphasizes on various rocks, strata and contact relationship. Third, Geo-trail C is mainly focused on geomorphological landforms and landscapes (Route C: Satgat Route), which provide information about different geomorphological landforms and the interaction between different geological agents. In order to operate these geotrail courses efficiently, installation of explanation boards and view points, cultivate local commentators, and visitor centers and experience programs should be properly prepared together.

• Journal of the Daesoon Academy of Sciences
• /
• v.38
• /
• pp.1-46
• /
• 2021

Since ancient times, the word Deok (德, virtue) has been used as a term in ethics. In the east, it originally meant 'to acquire (得),' and during the warring states period, it was used to indicate 'personality' or 'value;' especially for political leaders. Then, in Confucianism, the word Deok developed into an ethical term suggesting that people should acquire Deok in their action so as to achieve human perfection. In Daesoon Thought, Deok originates from the Dao, and the two are close in the same manner that Yin and Yang are close and interrelated. The Dao of Daesoon Thought indicates the Great Dao of Heaven and Earth, which Gucheon Sangje had opened when he performed his Gongbu (holy work) at Daewonsa Temple, is such that the Great Deok was divided into the Deok of Heaven, the Deok of Earth, and the Deok of Humanity. This allows for the realization of Deok in each of the Three Realms. Jo Jeongsan, the successor of Gucheon Sangje, said that he will inherit the Great Deok originated from the Great Dao and enlighten the world to the Dao. The cause of the accumulation of grievances in the Three Realms was due to the failure to sufficiently spread Deok throughout the Three Realms. The Later World is where Deok will be offered in its full extent as it was secured by the Cheonjigongsa (Reordering Works of Heaven and Earth) performed by Gucheon Sangje. However, as the main agent of spreading Deok is the heart-mind, humans need to cultivate their heart-mind in the correct way. When humans finally become Dotong-gunja (beings who are perfectly unified with the Dao) and generously practice Deok in the world, there will be no grievances anywhere in the Three Realms. There are four ways of practicing Deok: Deok by caring for life, Eondeok (Deok of speech), Gongdeok (practicing meritorious Deok), and Podeok (spreading of Deok) to the world. Practicing the Deok by caring for life is to save and protect living beings based on the spirit of Jesaenguise (saving lives and curing the world). Eondeok is practiced when people speak to others in a positive way that fosters widespread goodness based on the spirit of Sangsaeng (mutual beneficence). When people perform Gongdeok they will be rewarded for their actions. Podeok can be realized when the followers of Sangje spread the Great Dao of Heaven and Earth based on the teachings of Daesoon Thought.

• The Journal of Engineering Geology
• /
• v.22 no.1
• /
• pp.1-13
• /
• 2012

The purpose of this work is to gain a better understanding of the interrelationships between geological structures and slope failure in sedimentary rocks. In the studied slopes, construction-related slope failure could only be observed on the south-dipping slopes. This indicates that slope stability may be dependent on the angular relationships between the dip direction of bedding and the orientation of the slope. Slope failure continued, post-construction, around large fault zones in the studied outcrop; these fault damage zones are, however, not easily recognized in the field. Here we suggest a new method that uses accumulated fracture density to precisely identify fault damage zones. Multiple-faced slopes are now increasingly being exposed during large-scale construction projects in South Korea. This multiple-faced slope analysis indicates that the stability of a slope should be evaluated by identifying domains, through the analysis of possible slopes and their angular relationships with bedding and other discontinuities, prior to construction. Therefore, careful consideration of geological structures such as bedding and other discontinuities, and their angular relationships during the design of cuttings through sedimentary rocks, will increase the efficiency of construction and enable the safe construction of more stable slopes that will retain their stability after construction.