• Journal of IKEEE
• /
• v.26 no.2
• /
• pp.306-312
• /
• 2022

We investigated electrical properties and deep level traps in 4H-SiC merged PiN Schottky (MPS) diodes with different barrier heights by different PN ratios and metallization annealing temperatures. The barrier heights of MPS diodes were obtained in IV and CV characteristics. The leakage current increased with the lowering barrier height, resulting in 10 times larger current. Additionally, the deep level traps (Z_1/2 and RD_1/2) were revealed by deep level transient spectroscopy (DLTS) measurement in four MPS diodes. Based on DLTS results, the trap energy levels were found to be shallow level by 22~28% with lower barrier height It could confirm the dependence of the defect level and concentration determined by DLTS on the Schottky barrier height and may lead to incorrect results regarding deep level trap parameters with small barrier heights.

• Journal of the Korean Society of Safety
• /
• v.30 no.6
• /
• pp.164-173
• /
• 2015

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or assessment is not easy since absence on clear criteria or common definition. This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of methodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.1
• /
• pp.1-3
• /
• 1999

This study was carried out to determine the effects on rice growth, yields and soil improvement under the different nitrogen levels in machine-transplanted rice after plowing at the fruiting stage of milk vetch. The fresh weight of milk vetch at plowing time was 20.95 ton/ha. In dry weight, T-N and C/N were 1.58%, 21.8%, respectively. Organic matter, total nitrogen and exchangeable calcium of soil after the experiment in the plot of milk vetch were higher than those before the experiment. Leaf area and dry weight of rice plants at heading date increased as nitrogen level increased. The number of panicle and spikelets per $\textrm{m}^2$were not different except for the 110 kg/ha nitrogen level plot with milk vetch. Brown rice yield ranged from 5.45 to 6.08 ton/ha, in creasing with increased nitrogen level. So the yield increased by 1% at 77 kg/ha nitrogen level, 7% at 110 kg/ha nitrogen level plot with milk vetch compared with conventional level (rice straw 5.4 ton/ha and nitrogen 110 kg/ha).

• Proceedings of the Safety Management and Science Conference
• /
• 2010.04a
• /
• pp.141-147
• /
• 2010

Risk level for each construction work can be very important factors to establish advanced preventionmeasures. But it is important how to produce it. There are three different methods to set it up for consturuction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.3
• /
• pp.13-19
• /
• 2010

Risk level for each construction work can be very important factors to establish advanced prevention measures. But it is important how to produce it. There are three different methods to set it up for construction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

• Journal of Families and Better Life
• /
• v.19 no.1
• /
• pp.191-203
• /
• 2001

The purpose of this study is to find out the relationship among the identity, lifestyle and satisfaction with family resources of rural married persons. The subjects of this study were 435 married women and men in Ansung. The major findings were as follows: 1. The identity of rural married persons was significantly different depending on their gender and educational level. 2. Their lifestyle was significantly different depending on their gender, educational level, job, the type of dwelling, and family income. 3. Their satisfaction with family resources was significantly different depending on their educational level, job, the type of dwelling, and family income. 4. There was positive correlation among their identity, lifestyle and satisfaction with family resources of the rural married persons.

• Membrane and Water Treatment
• /
• v.1 no.1
• /
• pp.61-74
• /
• 2010

This paper will integrate models at different levels (from filtration, backwashing to chemical cleaning and membrane lifetime) that can be used to minimize overall operating costs of a dead-end ultra filtration process that is used for the purification of surface water. Integration of the models leads to a multi-level optimization problem (at different levels different objectives should be reached). This problem is solved as a MINLP. Systematic modelling and optimization of membrane systems is not extensively discussed in the scientific literature. In this paper the first steps are taken in the formulation of proper models and the use of systems engineering tools to come to real optimal operating conditions. The optimized variables are used to calculate fouling profiles which can subsequently be used as inputs for a control system that actually enforces the profiles to a real pilot plant.

• Journal of Technology Innovation
• /
• v.6 no.1
• /
• pp.215-249
• /
• 1998

This study empirically examines the relationship between the career orientations of R&D professionals and their demographic characteristics (age, tenure, and education level), affiliated organizations (public and private organizations), reward systems. It further explores the contingent effects of the career orientation fit between leader and members on their performance. The results reveal that : 1) five different career orientations (technical, manager, project, technical transfer, and entrepreneur) are empirically distinguished, 2) technical orientation of R&D professionals is higher in public in private sectors, 3) technical, project, and manager orientation are positively associated with the education level, while technical transfer and entrepreneur orientation are negatively associated with the education level, 4) manager and technical transfer orientation is positively related with age and tenure, 5) the career orientation fit between leader and member is closely related with job satisfaction and organization commitment, and partially related with technical performance, 6) R&D professionals with different types of career orientation exhibit different preference to various rewards. Based on these findings, this study suggests several practical implications for the design of career ladder, mentoring, and reward systems of R&D professionals.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.6
• /
• pp.1036-1040
• /
• 2007

Sodium butyrate (NaBu) has been used to enhance protein expression levels in mammalian cell culture. To determine the clonal variability of recombinant Chinese hamster ovary (rCHO) cells in response to NaBu addition regarding specific antibody productivity $(q_{Ab})$, three rCHO clones were subjected to different concentrations of NaBu. For all three clones, NaBu addition inhibited cell growth and decreased cell viability in a dose-dependent manner. On the other hand, the enhancing effect of NaBu on $q_{Ab}$ varied significantly among the clones. NaBu addition enhanced the antibody production of only one clone. RT-PCR analysis revealed that the changes in $q_{Ab}$ correlated linearly with those of the mRNA transcription level. Thus, it was concluded that the different enhancing effects of NaBu on protein expression in rCHO cell clones resulted from their different mRNA transcription levels.

• Communications for Statistical Applications and Methods
• /
• v.11 no.2
• /
• pp.369-380
• /
• 2004

Clustering algorithms with different similarity measures are commonly used to find an optimal clustering or close to original clustering. The recovery level of using Euclidean distance and distances transformed from correlation coefficients is evaluated and compared using Rand's (1971) C statistic. The C values present how the resultant clustering is close to the original clustering. In simulation study, the recovery level is improved by applying the correlation coefficients between objects. Using the data set from Spellman et al. (1998), the recovery levels with different similarity measures are also presented. In general, the recovery level of true clusters was increased by using the correlation coefficients.