• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.341-347
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• 2009

Soil microbial community has been changed after the treatment of anaerobic fermentation using wheat bran or rice bran was applied to the soil. In the dilution plate technique, the number of anaerobic bacteria and fungi was higher in rice bran-treated soil than in non and wheat bran-treated soil, but of yeast was higher in wheat bran-treated soil than in non and rice bran-treated soil. Specially, the fungi were not detected in the wheat bran-treated soil. Identified by 16S rDNA sequencing, the number of aerobic bacteria was similar in all treatments, the dominant bacteria was the genus Bacillus. In the phospholipid fatty acid (PLFA) technique, both Gram-positive and Gram-negative bacteria change slightly in all treatments for 20 days of fermentation process but, after 20day, increased rapidly in wheat or rice bran-treated soil. In conclusion, the microbial communities structure was dramatically changed after the treatment of wheat or rice bran to soil.

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.55-65
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• 2019

This paper describes results of experimental and numerical analyses, in order to analyze a reinforcement effect of concrete mat on open cut restoration of underground cavity. The plate loading tests were conducted to evaluate a reinforcement effect of concrete mat, at reinforcement depths from the ground surface of 10 cm, 20 cm, and 30 cm. The result showed that the reduction ratio of stress (earth pressure) was about 60% at all reinforcement depth. The reinforcement effect considering ground surface settlement and reduction ratio of stress based on laboratory tests and numerical analysis was significant, at reinforcement depths from the ground surface of 10 cm~20 cm. LFWD test results showed that subgrade modulus was the largest when concrete mat was installed 20 cm below ground surface. Therefore, it is effective to reinforce concrete mat within 20 cm from the surface, when the underground cavity due to damage of underground utilities was formed in the height direction to the bottom of the pavement layer.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.179-187
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• 2023

Consumer trust plays a crucial role in the development of the sharing economy. This study primarily focuses on the factors influencing consumer trust and examines the case of ofo, a former leader in China's bike-sharing industry. This paper analyzes the decline in consumer trust in ofo, which can be attributed to internal management issues and the near-bankruptcy situation. The "difficulty in refunds" issue faced by ofo since December 2018 has been growing continuously, and this study explores the factors influencing trust and distrust in this context. By considering product factors (quality), platform factors (payment security, privacy protection, reputation), and social factors (social norms, government regulation) as independent variables, the study analyzes the factors affecting consumer trust. The analysis results revealed that as consumers' distrust towards shared bikes increases, their switching intention also increases. The company's reputation and social norms were found to influence both trust and distrust, while government regulation was found to influence trust. The research findings provide insights relevant to sharing economy platforms and offer guidance for future studies.

• Journal of Industrial Convergence
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• v.22 no.3
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• pp.27-37
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• 2024

The purpose of this study was to analyze the impact of community characteristics of induced participants on values, attitudes, and behaviors (VAB) and intention to continue participation. Convenience sampling (n=192) was used to sample the research subjects, and confirmatory factor analysis, correlation analysis, and structural equation modeling were conducted using SPSS 26.0 and AMOS 26.0. The results of this study are as follows. 1) Among the community attributes of the participants, reputation, enjoyment, interaction, and social connection had a significant impact. 2) Value-Attitude-Behavior (VAB) was found to have a significant hierarchical impact. 3) Behavioral intention was found to have a significant effect on continuation intention. Through this, the Judo community needs to build a participant-centered organizational culture that can create positive value in order to increase participants' participation in Judo.

• Korean Journal of Materials Research
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• v.6 no.2
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• pp.166-174
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• 1996

경제적이고 단순성의 공정특성을 갖는 닥터 블레이드법을 이용하여 평판형 고체산화물 연료전지의 고체전해질용 이트리아 안정화 지르코니아 박막을 제조하였다. 슬러리의 최적 제조조건과 그린 필름의 최적 소성조건을 얻었으며, 이 제조 조건에서 제조된 전해질의 결정구조, 미세구조 그리고 전기적 성질을 각각 X-선 회절, 주사전자현미경 그리고 교류 임피던스 분석기를 이용하여 조사하였다. 동량의 8mol% 이트리아를 첨가한 경우, 닥터 블레이드법에 의해 제조된 이트리아 안정화 지르크니아 박막은 금형가압성형법에 의해 제조된 이트리아 안정화 지르코니아 펠렛과 거의 비슷한 전기전도도를 나타내었다. 닥터 블레이드법에 의해 제조된 이트리아 안정화 지르크니아 박막의 경우, 8mol%이트리아를 첨가한 경우의 전도도가 3mol%이트리아를 첨가한 경우 보다 993K 이상과 523K 8mol% 이트리아를 첨가한 경우의 전도도가 3mol%이트리아를 첨가한 경우의 전도도가 3mol%이트리아를 첨가한 경우 보다 993K이상과 523K이하의 온도에서는 더 높고, 523-933K사이의 온도구간에서는 낮게 나타났다. 게다가, 모든 시편에 있어서 전체 전도도에 대한 벌크 전도도의 기여도에 대한 기여도보다 더 크게 나타났다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1594-1600
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• 2011

Recently developed FDS5 CFD code has employed a near-wall flow treatment method which is Werner-Wengle wall law provided by NIST(National Institute of Standards and Technology). In this study, the wall law has been verified against DNS(Direct Numerical Simulation) data in the parallel plate. The $y^+$ was kept above 11 to fulfill the near-wall flow requirement in the grid generation. The total grid was $32{\times}32{\times}32$. The boundary condition for inlet and outlet was periodic condition and for both side, symmetric condition was used. The fully developed turbulent flow was generated and Re = 10,700. The simulated results were compared with DNS data. RANS results were also used for verification.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.7
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• pp.719-725
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• 2009

An efficient time-domain numerical method for the analysis of broadband noise generation and propagation due to turbulence-cascade interaction is developed. The core algorithm of the present method is based on the B-periodicity of the acoustic response function of the flat-airfoil cascade to the ingesting gust(B denotes the number of airfoils in the cascade). To confirm this periodicity, gust-cascade interaction problem are solved by using the time-domain method, which shows that the incident gust with the circumferential mode number having the same remainders when divided by the airfoil number excites the same acoustic response of the cascade. Using the proposed fast algorithm with this periodicity, we show that the total computation time for the model broadband problem using the total 525 incident gust modes can be reduced to about 1/4 of that taken in using the previous time-domain program.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.488-492
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• 2016

Saccharomycopsis fibuligera is an amylolytic yeast that exhibits raw starch-degrading activity. In this study, adaptive laboratory evolution was performed to improve the tolerance of S. fibuligera to lactic acid by prolonged repeated batch fermentation in which the lactic acid concentration was gradually increased. The evolved S. fibuligera strain exhibited a significantly enhanced tolerance to lactic acid at concentrations up to 2.5% (w/v), as assessed by determining its specific growth rate using a plate assay. Scanning electron microscopy revealed an elongated and perforated morphology of the parent strain under lactic acid stress, indicating that its membrane might be more prone to damage caused by lactic acid than that of the evolved strain.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.2
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• pp.249-253
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• 1996

The development of electronic technology brings the advent of electronic tacheometer which measures, stores and records automatically angles and distances. Electronic tacheometer is the surveying equipment that enable the acquisition of the 3-D terrain information, construction of the database and automatic drafting of the cartographic map. This paper aims at studying the system which can produce automatically the digital cartographic map by us-ing the electronic tacheometer. For this study, cartographic maps of a region are produced by a plane table and an electronic tacheometer and these is analysed. The results of this study show that digital cartographic map by electronic tacheometer is much more accurate and efficient than cartographic map by plane table.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.87-99
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• 1993

The computer program, MFPD, which is used to backcalculate the layer moduli of asphalt concrete pavement system is modified by contemplating the depth to virtual bedrock in this study. An algorithm to estimate the depth to virtual bedrock is developed through the analysis of FWD impulse load duration and the compression wave velocity of ground. For verification of the modified MFPD, FWD is fabricated and then FWD field tests and verification tests are carried out at the test sites. Plate loading tests and surface wave propagation tests are performed at FWD test sites. Laboratory tests (Marshall stability tests, unconfined compression tests) for sampled asphalt concrete specimens are also carried out. From comparison analysis, the validity and applicability of the modified MFPD are verified.