• International conference on construction engineering and project management
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• 2011.02a
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• pp.249-255
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• 2011

Poor safety management in construction management may adversely affect cost, schedule and quality of a project. Heavy fines upon safety offence becomes a burden to the budget; losing working hours as a result of safety incident impacts on the schedule, and compromising quality is always an indirect consequence when workers perform duties in an unsafe site environment. Therefore, promotion of safety management becomes the top priority in any construction manager's agenda. Working safely will benefit construction project and lead to a "real" success. This paper is a case study, based upon "Geller's 10 principles for achieving a total safety culture", reviewing how a Hong Kong leading construction company fosters the safety culture and possesses a pleasant safety record over years. Its safety performance is not only well ahead the local industry, but also ranges top within the Asia Pacific region and comparable to those mature Western industries. The review concluded that safety culture is one of the major components in construction management and collaboration is the essence to realize this positive culture within an organization. Safety management is not merely a "top down" approach, but requires the positive "bottom up" actions from the other end. The successful story of this company can demonstrate the contribution of safety management in construction management.

• Advances in Computational Design
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• v.8 no.4
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• pp.295-307
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• 2023

This paper presents an optimization of the reinforced concrete ribbed slab in terms of minimum CO₂ emissions and an economic justification of the final optimal design. The design variables are six geometry variables including the slab thickness, the ribs spacing, the rib width at the lower and toper end, the depth of the rib and the bar diameter of the reinforcement, and the seventh variable defines the concrete strength. The objective function is considered to be the minimum amount of carbon dioxide gas (CO₂) emission and at the same time, the optimal design is economical. Seven significant design constraints of American Concrete Institute's Standard were considered. A robust metaheuristic optimization method called improved dolphin echolocation and ant colony optimization (IDEACO) has been used to obtain the best possible answer. At optimal design, the three most important sources of CO₂ emissions include concrete, steel reinforcement, and formwork that the contribution of them are 63.72, 32.17, and 4.11 percent respectively. Formwork, concrete, steel reinforcement, and CO₂ are the four most important sources of cost with contributions of 67.56, 19.49, 12.44, and 0.51 percent respectively. Results obtained by IDEACO show that cost and CO₂ emissions are closely related, so the presented method is a practical solution that was able to reduce the cost and CO₂ emissions simultaneously.

• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.209-219
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• 2024

We studied the effects of science high school students on the change of epistemological beliefs in chemistry and the academic achievement of chemistry by completing 'advanced chemistry'. For seven months from July 2023 to January 2024, 80 first-year students at G Science High School in Gyeongnam were surveyed and analyzed for epistemological beliefs about chemistry before and after classes in advanced chemistry. Chemistry academic achievement was classified by 'upper' and 'lower' levels based on the end-of-semester grades of 'advanced chemistry' in the second semester of the first year and analyzed with the SPSS 28 program. After completing advanced chemistry, the epistemological belief in chemistry increased in the proportion of favorable responses. After completing advanced chemistry, the proportion of favorable responses increased in detailed factors such as 'effort', 'math link', 'outcome', 'reality link', and 'concepts', while the 'visualization' factor decreased. Although completing 'advanced chemistry' positively changed students' epistemological beliefs about chemistry, visual expression showed little contribution to understanding chemical concepts. Based on the above results, we will have to focus on the design of instructors' teaching-learning, such as learner-centered inquiry experiments, creative visual expressions, etc., for successful chemistry teaching-learning.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.1
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• pp.121-143
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• 2019

The purpose of this study was to examine the reason and value system of the elderly people on the public library use in Korea. For the purpose, a questionnaire survey was conducted for elderly aged over 60, from 15 public libraries in Seoul from October 29 to October 10, 2018, and 306 valid responses collected were analyzed. The value system is based on the Means-end Chain (MEC) Theory, and the linkage between the attributes, consequences, and values of public library use is figured out as a value hierarchy. As a result, the most frequently revealed value system was 'reads or borrows books (attribute) ${\rightarrow}$ gets new knowledge (consequence) ${\rightarrow}$ satisfies oneself (value).' For the value reached by using the public library, both groups answered that their satisfaction, achievement, fun, pleasure, and vitality. However, the elderly aged 65 and over additionally felt that public libraries are good for their mental / physical health. The results showed that the elderly people using the public library feels the traditional functions of the public library as the main attribute, and the public library could provide the elderly people with contribution to the lively old age.

• Journal of Korean Society of Forest Science
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• v.31 no.1
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• pp.48-52
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• 1976

In order to investigate the effects of seed weight, size (length and thickness), and maturation period (early maturing seed or late maturing seed) on growth of first-year seedlings in Pinus koraiensis, pot cultivation experiment with seeds collected from Gangweon University Forest was carried out under relatively controlled environment condition. At the end of one growing season, not only fresh weight, length, diameter (at underside of cotyledon) and root length of seedlings, but also number and length of cotyledon were measured. Results are as follows; 1. Germination percentage is independent of weight and size of seeds, but it was influenced by maturation period, that is, late maturing seeds surpass early maturing one in germination percentage. 2. Germination percentage is affected by maturation period of seeds in 18.3% of contribution rate. 3. Each growth of first-year seedlings is influenced considerably by the differences of weight, length and thickness of seeds, that is, heavy and large seeds produce larger seedlings than do light and small seeds. Particularly, fresh weight, diameter, length of cotyledon are significantly affected by differences of seed weight and size (length and thickness) in 50-90% of contribution rate. 4. Differences of seed weight and thickness have a tendency to affect more on growth of first-year seedlings than do differences of seed length. 5. Seedlings from late maturing seeds are superior than those from early maturing one in fresh weight, diameter of seedlings and length of cotyledon, but it's influence is a little.

• Journal of Gifted/Talented Education
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• v.27 no.1
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• pp.59-80
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• 2017

In this study, we investigate social preference of gifted students by analyzing their behaviors in social dilemma situations. We conducted an experimental study using ultimatum games and public goods games with 132 academically gifted middle school students who attended the Ewha-Seodaemun Center for gifted education from 2012 to 2016. We also experimented the same games with 87 regular students for comparative analysis. The result of ultimatum game experiment shows that there is no statistical difference in the proposed share of both groups. Their proposed share ranges from 37% to 38% as expected in other similar studies. However, the rejection rate of the respondents to the proposals with small share are significantly higher among gifted students than among their regular counterparts. This result implies that the gifted students show stronger negative reciprocity, meaning that they tend to punish selfish behaviors even when it takes some costs. In finitely repeated public goods game experiments, the results show that both groups' contribution rates decrease toward the end of the experiments. However, the gifted students show strategic cooperation by attempting to increase the other members' contribution rate within an experimental group. This implies that gifted students tend to care more about how to increase their own expected rewards by reciprocating other students' behaviors.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.439-449
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• 2019

To prevent the drying-out of streams and to make effective use of stream water and groundwater, it is necessary to evaluate the impact of groundwater pumping on nearby streams. To this end, stream depletion due to groundwater pumping should be investigated in terms of various hydraulic characteristics of the aquifer and stream. This study used the Baalousha analytical solution, which accounts for stream-stage variation over time, to analyze stream depletion due to groundwater pumping for cases where the stream level decreases exponentially and recovers after the decrease. For conditions such as an aquifer transmissivity of 10~100 ㎡ d^-1, storage coefficient 0.05~0.3, streambed hydraulic conductance 0.1~1.0 m d^-1, stream-well distance 100~500 m, and stage recession coefficient 0.1~1.0 d^-1, the contribution of stream water (the dimensionless ratio of stream water reduction rate to groundwater pumping rate) was analyzed in cases where stream level change was considered. Considering the effect of stream-stage recession, the contribution of stream water is greatly reduced and is less affected by the stream-depletion factor, which is a function of the stream-to-well distance and hydraulic diffusivity. However, there is no significant difference in stream depletion under constant- and variable-stage recovery after recession. These results indicate that stream level control can distribute the relative impacts on stream water and aquifer storage during groundwater pumping

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.59.4-60
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• 2018

To investigate the impact of the high-redshift quasars on cosmic reionization, the faint end slope of the quasars luminosity function has to be determined precisely. More quasars with low luminosity are needed to constrain the contribution to reionization in the early universe. However, finding these quasars has been regarded as tough process owing to the improper shallow depth of imaging data. In recent days, the release data of Subaru Hyper Suprime-Cam (HSC) Strategic Program survey which provide the deep images reaching ~ 25 mag facilitates searching the faint quasars candidates. To find faint quasar candidates in ELAIS-N1 field, along with the HSC data, two near-infrared (NIR) data sets also be used : The Infrared Medium-deep Survey (IMS) and The UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep Extragalactic Survey (DXS). Quasar candidates selected from the multi-band color cut were observed by the SED camera for QUasars in EArly uNiverse (SQUEAN) instrument. To trace the redshifted Lyman break efficiently, appropriate medium bands comparable to targeted redshift range are chosen. The most reliable quasar candidates are finally determined through SED fitting. Using this less luminous quasars candidates, we can speculate the relation between the quasar growth and the host galaxy unbiasedly and estimate the contribution to the cosmic reionization.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.4
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• pp.67-78
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• 2016

Recently many countries around the world are actively promoting smart city projects to address various urban problems such as traffic congestion, housing shortage, and energy scarcity. Due to development of the Internet of Things (IoT), the development of a smart city with sustainability, convenience, and environment-friendliness was enabled through the effective control and reuse of urban resources. The purpose of this study is to analyze the technical trends of IoT and present a development plan for smart city which is one of the applications of the IoT. To this end, the news articles of the Electronic Times between 2013 and 2015were analyzed using the text mining technique and smart city development cases of other countries were investigated. The analysis results revealed the close relationships of big data, cloud, platforms, and sensors with smart city. For the successful development of a smart city, first, all the interested parties in the city must work together to create new values throughout the entire process of value chain. Second, they must utilize big data and disclose public data more actively than they are doing now. This study has made academic contribution in that it has presented a big data analysis method and stimulated follow-up studies. For the practical contribution, the results of this study provided useful data for the policy making of local governments and administrative agencies for smart city development. This study may have limitations in the incorporation of the total trends because only the news articles of the Electronic Times were selected to analyze the technical trends of the IoT.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8386-8393
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• 2015

This study is to investigate the needs for the cool motorcycle helmet and the factors affecting the purchasing intention of cool helmet. The convenient sampling from motorcycle clubs were conducted during 5/20/2014~5/28/2014 on Google DAX. As a result, 197 participants were surveyed. The main reasons of sensing unpleasant feeling wearing helmet were identified as 'hot and uncomfortable feeling' and 'it ruins hair style'. The mean score expressed in terms of five point scale showed that the needs for cool helmet was 3.9 and the purchasing intention of cool helmet was 3.6, respectively. The significant factors influencing the purchasing intention of cool helmet were identified as 'the needs for cool helmet' (odds ratio=6.52) and 'extra paying intention for cool helmet' (odds ratio=1.77). The main reasons of sensing unpleasant feeling wearing helmet were similar to the previous research. However, we can expect that the initial target market for cool helmet would be the low end (less than \40,000 of extra paying intention) or the high end (more than \100,000 of extra paying intention). The main contribution of this study is dealing with the topics related to the purchasing intention of the cool helmet.