• Journal of the Korean Society for Precision Engineering
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• v.34 no.3
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• pp.191-197
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• 2017

Light detection and ranging (LiDAR) is one of the most efficient technologies to obtain the topographic and bathymetric map of coastal zones, superior to other technologies, such as sound navigation and ranging (SONAR) and synthetic aperture radar (SAR). However, the measurement results using LiDAR are vulnerable to environmental factors. To achieve a correspondence between the acquired LiDAR data and reality, error sources must be considered, such as the water surface slope, water turbidity, and seafloor slope. Based on the knowledge of those factors' effects, error corrections can be applied. We concentrated on the effect of the seafloor slope on LiDAR waveforms while restricting other error sources. A simulation regarding in-water beam scattering was conducted, followed by an investigation of the correlation between the seafloor slope and peak timing of return waveforms. As a result, an equation was derived to correct the depth error caused by the seafloor slope.

• Journal of the Korean Home Economics Association
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• v.36 no.5
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• pp.29-46
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• 1998

This study investigates how the consumers utilize the elements of information search and how consumers are satisfied with them. For this study, drives who have bought their own cars in two years were chosen for subjects of investigation. And samples were interviewed with an organized questionaire from July 8 to July 27, 1996. 300 samples were used for the final analysis. The major results from this study are as follows. 1) In general information search, consumers get a great deal of information from a talk their friends, neighbors, or colleagues, and they obtain information from an experienced person or a professional. In using sources of information search, they made the best use of their experiences, which is the sources of internal information, and for the second, they used advertising and the explanation of a salesman. In using the contents of information search, they made the best use of information about the merits and demerits in each attribute. In using the method of information search, the mixed search 1 method was used the most, and the attribute search method was used. 2) The casual relationship between the general satisfaction for the products and the relative variable was investigated. An age, the time pressure, the information of the products had a direct and indirect influence on the general for the products. The perceived risk, the number of inquiring activity, a shop and the buying method had a direct influence on the general for the products. An indirect influence was showed in the general satisfaction for the products through the medium of inquiring activity, a shop, and buying method.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.171-178
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• 1997

Vehicle interior noise has become increasingly important in this recent years. The noise of a vehicle is one of the important problems in a vehicle design. The interior noise is caused by various vibration sources of vehicle compartment. The booming noise of a vehicle can be significantly affected by vibrations transmitted from engine excitation forces to the vehicle body. Specially, we are interested in the state of transmission paths such as engine mounts to reduce noise in a vehicle compartment. In this paper, we have been calculated the contribution of each transmission path such as engine mounts to interior noise. To identify contribution of each input sources and transmission paths to output, the effectiveness of each input component to output is calculated. Sensitivity analysis is carried out for investigation of contribution to output due to input variations. With the simulation of magnitude and phase change of inputs using vector synthesis diagram, the trends of synthesized output vector are obtained. As a result, we suggested sensitivity analysis of vector synthesis as a technique of prediction and control for noise in a vehicle compartment.

• Mycobiology
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• v.33 no.3
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• pp.147-149
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• 2005

The investigation was undertaken to enhance the decomposition process by pre-treatment of rice stubble, having higher concentration of lignin. Air-dried rice stubble was treated with 1.8 liter of 1% NaOH and autoclaved. Six cellulolytic fungi, Trichoderma harzianum, Penicillium citrinum, Curvularia lunata, Aspergillus flavus and Alternaria alternata were grown in basal synthetic medium along with delignified rice-residue as carbon source for production of soluble crude protein. Though the loss of cellulose has been observed by all of them but having a considerable status in the presence of T. harzianum and T. harzianum yielded highest percentage of crude protein (27.99%) with biomass of 375 mg, whereas the lowest protein value (17.91%) was recorded in case of A. niger with biomass of 422 mg. Among the imperfect fungi, T. harzianum was the most potent. Effects of incubation period and nitrogen sources on soluble crude protein production by T. harzianum were also undertaken in this study. Fifth day of incubation period and potassium nitrate as nitrogen source among other nitrogen sources was found most appropriate for soluble crude protein production by the mentioned organism.

• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.27-35
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• 2013

In this study, three dimensional and two dimensional laboratory experiments were conducted to investigate the effect of water table rising on DNAPL migration, contaminants mass discharge ($M_d$), and residual NAPL distribution. The accumulation of TCE in unsaturated zone was observed in both two and three dimensional experiments. This implies DNAPL sources could exist in unsaturated zone at contaminated sites. It has been investigated that the TCE concentration is proportional to the areal ratio of residual TCE. This means the residual TCE obviously could affect the TCE concentration in aquifer system. The results of the two-dimensional experiment indicated that the contaminant sources in unsaturated zone could lead the $M_d$ increasing with water table rising and the source zone heterogeneity could also highly affect the $M_d$.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.28-38
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• 1994

The objective of this study were to measure concentrations of indoor pollutants in public transportation systems to provide importance of indoor air quality in transportation systems to policy makers. Indoor air quality of the pollutants (CO, CO$_2$, PM-10) and environmental sources (temperature, humidity) were measured at subway, seat-type bus, and city-type bus in the Seoul area from April to September 1992. The same pollutants and environmental sources were also measured at selected bus stops and subway stations during October 1991-September 1992. The mean concentrations of indoor pollutants in the public transportation systems were showed 115.5 $\mu$g/m$^3$ in PM-10, 6.8 ppm in CO, and 2167.9 ppm in CO$_2$, respectively. The mean values of PM-10 and CO showed below the U.S. 24 hour standard value of PM-10 and the Korea ambient CO standard, while the mean concentrations of CO$_2$ exceeded the Korea CO$_2$ standard. The highest levels of indoor concentration at public transportation systems were PM-10 of 134.6 $\mu$g/m$^3$ in the subway, CO of 8.9 ppm in the city-type bus, CO$_2$ of 2,511.1ppm in seat-type bus, respectively. The results showed that indoor air quality in bus and subway seemed likely to be affected by number of passengers and outdoor air infiltrated from exhausted gases of automobiles.

• Ocean Systems Engineering
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• v.8 no.3
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• pp.313-327
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• 2018

Meeting the touchdown point (TDP) target box is one of the challenges during catenary riser installation, especially for deep water or ultra-deep water riser systems. TDP location mismatch compared to the design can result in variation of riser configuration, additional hang-off misalignment, and extra bending loads going into the hang-off porch. A good understanding of the key installation parameters can help to minimize this mismatch, and ensure that the riser global response meets the design criteria. This paper focuses on investigating the potential factors that may affect the touchdown point location, and addressing the challenges both in the design stage and during installation campaign. Conventionally, the vessel offset and current are the most critical factors which may affect the TDP movement during installation. With the offshore exploration going deeper and deeper in the sea (up to 10,000ft), other sources such as the seabed slope and seabed soil stiffness are playing an important role as well. The impacts of potential sources are quantified through case studies for steel catenary riser (SCR) and lazy wave steel catenary riser (LWSCR) in deep water application. Investigations through both theoretical study and numerical validation are carried out. Furthermore, design recommendations are provided during execution phase for the TDP mismatch condition to ensure the integrity of the riser system.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.27-37
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• 2007

Proficiency test is an essential tool far ensuring analytical ability of analytical chemists and analytical institutes. Usually, the standard protocol for proficiency test is focused on acceptability of reported analytical results of participants by calculating z-scores and related diagnostic parameters. The ultimate goal of this process is to reveal the sources of variability of analytical results and to find the way to reduce their influence. In this study, the method of analysis of variance (ANOVA) was applied to the analytical data collected from qualify control departments of pharmaceutical companies in KyungIn province in Korea in the year of 2000. As influencing factors of variability of analytical results, the use of internal standards for liquid and gas chromatograpy, the educational and professional background of participants, geological locations and yearly production sizes of participating companies were evaluated. To evaluate the variability in accuracy of analytical results, absolute differences from sample mean and sample median were used and to evaluate variability in precision of individual participants, the reported standard deviation of each participant was used. As a result, the use of internal standards in gas chromatographic analysis, participants' academic background and the yearly production sizes of pharmaceutical companies showed statistically significant influence to the accuracy and the precision of the reported analytical results used in this study.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.155-160
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• 2009

The increasingly high prices for oil, the exhaustion of fossil fuels as well as concern about global warming are driving rapid growth of alternative sources of energy in the world. The active solution for global environment and exhaustion of energy sources is to develop and popularize the technologies to use natural energy such as sunlight, wind, and water. PV(Photovoltaic) modules are efficient devices that has been considered a logical material for use in buildings. Recent advanced BIPV(Building Integrated PV) technology have rapidly made PVs suitable for direct integration into construction in the world. Recently, building has been higher and higher. Tall buildings have many advantages for BIPV such as wide facade area and no shading effect by the surrounding buildings. However. BIPV has not been applied for tall building facade yet. Therefore, the purpose of the research is to develop suitable BIPV for tall buildings and to put these technologies to practical use. Therefore, the purpose of the study is to investigate unification of BIPV to curtain wall to apply BIPV on tall building through research into advanced application of overseas BIPV cases.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.159-168
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• 2005

Dye-sensitized solar cells (DSCs) have been under investigation for the past decade due to their attractive features such as high energy conversion efficiency and low production costs. The basis for energy conversion is the injection of electrons from a photoexcited state of a dye sensitizer into the conduction band of the nanocrystalline $TiO_2$ semiconductor upon absorption of light. It is believed that the DSC is one of the most promising candidates for renewable energy sources. In this review, the development trends and perspectives of DSCs are investigated.