• 아태비즈니스연구
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• 제11권4호
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• pp.317-332
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• 2020

Purpose - This study examines the information effect and trading behavior of investors for the 430 stock split data from January 2004 to June 2018 in the Korean stock market. Design/methodology/approach - The stock split samples are classified into two groups by split ratio as well as three groups by price level prior to split. We also investigate the trading behavior of investors categorized by institutional versus individual investors. Findings - First, we find a significantly positive information effect on the announcement day. In particular, the information effect is more distinct in the group of larger split ratio and higher price level of stocks. Second, we find a huge increase in turnover following the stock splits, which mainly results from the trading by individual investors. Also, the increase in turnover by individual investors is evident in the group of larger split ratio and higher price level of stocks. Third, the stock splits have a negative impact on the long-term stock performance. The negative buy-and-hold abnormal return(BHAR) makes no difference in the groups by split ratio as well as price level of stocks. Lastly, we find individual investors tend to buy splitted stocks, which exhibit the long-term under-performance. Research implications or Originality - The results in this paper suggest that the liquidity hypothesis is not supported in the Korean stock splits. In addition, we observe that individual investors are exposed to losses due to their unfavorable trading behavior following the stock split.

• 대한임베디드공학회논문지
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• 제14권5호
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• pp.249-258
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• 2019

In the cyber-physical system, big data collected from numerous sensors and IoT devices is transferred to the Cloud for processing and analysis. When transferring data to the Cloud, merging data into one single file is more efficient than using the data in the form of split files. However, current merging and splitting operations are performed at the user-level and require many I / O requests to memory and storage devices, which is very inefficient and time-consuming. To solve this problem, this paper proposes kernel-level partitioning and combining operations. At the kernel level, splitting and merging files can be done with very little overhead by modifying the file system metadata. We have designed the proposed algorithm in detail and implemented it in the Linux Ext4 file system. In our experiments with the real Cloud storage system, our technique has achieved a transfer time of up to only 17% compared to the case of transferring split files. It also confirmed that the time required can be reduced by up to 0.5% compared to the existing user-level method.

• 응용통계연구
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• 제8권2호
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• pp.55-64
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• 1995

다단계 스킵-로트 샘플링 검사계획(Choi, 1993)을 수정하여, 1단에 정규검사 2단에 단지(段地, terrace)검사를 둔 2단으로 분할된 스킵-로트 샘플링 검사계획을 설계하였다 스킵-로트 샘플링 검사계획은 제품의 품질이 우수할 경우에는 더 높은 단계의 검사를 수행하고, 그렇지 않을 경우에는 곧 바로 정규검사 또는 단지검사로 되돌아가도록 되어 있다. 마코프 연쇄를 이용하여 분할된 3단계의 샘플링 검사계획의 검사특성곡선을 도출하여 그 성질을 규명하고, Choi의 샘플링 검사계획과도 비교하였다.

• 대한원격탐사학회지
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• 제11권1호
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• pp.31-45
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• 1995

The values of brightness temperature difference (BTD) between 11um and 12um infrared channels may reflect amounts of low-level water vapor and cloud types due to the different absorptivity for water vapor between two channels. A simple method of classifying cloud types at night was proposed. Two-dimensional histograms of brightness temperature of the 11um channel and the BTD between the split window data over subareas around characteristic clouds such as Cb(cumulonimbus), Ci(cirrus), and Sc(stratocumulus) was constructed. Cb, Ci and Sc can be classified by seleting appropriate thresholds in the two-dimensional histograms. And we can see amounts of low-level water vapor in clear area as well as cloud types in cloudy area in the BTD image. The map of cloud types and low-level water vapor generated by this method was compared with 850hPa and 1000hPa relative humidity(%) of numerical analysis data and nephanalysis chart. The comparisons showed reasonable agreement.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 춘계학술대회
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• pp.277-292
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• 2012

The research presents an application of Balanced ANOVA (BANOVA) by utilizing randomized orders for various Split-Plot Designs (SPDs) which include two cell designs, split-plot with one-way HTC (Hard to Control) factor, split-plot with two-way HTC factor, split-split-plot design and nested design. In addition, four MINITAB examples of 2-level split-plot designs based on the number of blocks and the type of whole-plots are presented for practitioners to obtain comprehensive understanding. Furthermore, the geometrical interrelated properties among three typical Designs of Experiments (DOE), such as Factorial Design (FD), Response Surface Design (RSD), and Mixture Design (MD) are discussed in this paper.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2965-2970
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• 2008

Effects of split injection and oxygen-enriched air on soot emissions in a DI diesel engine were studied by the KIVA-3V code. When split injection is applied, the second injection of fuel into a cylinder results in two separate stoichiometric zones which increases soot oxidation. As a result, soot emissions are decreased with split injection. When oxygen-enriched air is applied together with split injection, higher concentration of oxygen helps secondary combustion which results in a higher temperature in the cylinder. The increased temperature promotes growth reaction of acetylene with soot but doesn't improve the acetylene formation during the second injection of fuel. As more acetylene is consumed in the growth reaction of acetylene, the net acetylene mass in the cylinder is decreased, which leads to a decrease of soot formation. With an increase of soot oxidation caused by split injection, the soot emissions are decreased significantly. However, to avoid excessive NOx emissions with increased oxygen concentration, the level of oxygen concentration should be lower than 22% in volume.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.144-152
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• 2006

Split injection has been known to reduce total hydrocarbon (THC) emission level and increase engine performance under certain operating conditions 1, 2). Exhaust Gas Recirculation (EGR) is a common technique adopted for nirtric oxides (NOx) reduction by the dilution of intake air, despite a sacrifice of simultaneous increase in THC and decrease in engine performance3). Thus, using split injection with adequate EGR may improve the emission level of UBHC, NOx and the engine performance compared to that of single-injection with or without EGR cases. The purpose of this study is to investigate the engine performance and emission levels at various engine operating conditions and injection methods when it is applied with EGR. The characteristics of single-injection and split-injection were investigated with various engine loads and EGR rates. The engine speed is changed from 800rpm to 1200rpm to investigate how the combustion characteristics are changing with increasing engine speed.

• Journal of Korean Neurosurgical Society
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• 제54권4호
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• pp.363-365
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• 2013

Split cord malformations (SCMs) usually present in childhood, and are rarely reported in adults. And also, a cervicothoracic SCM associated with tethered cord syndrome has very rarely been reported in the literature. We report a case of SCM associated with tethered cord and spina bifida in an adult. This report describes the case of a 34-year-old woman who presented for evaluation of neck pain, back pain, and intermittent paraparesis of several months duration. The MRI and CT showed a SCM at the cervicothoracic level and a fibrous septum at the thoracic level. She underwent surgery for the SCM and tethered cord syndrome, and was followed for 7 years. Patient presented complete recovery in the follow-up. The authors discuss this unusual lesion and describe the anatomical relationship of the level of cord duplication and fibrous septum.

• 산업기술연구
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• 제23권A호
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• pp.139-147
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• 2003

The purpose of this study was to investigate and analyze the fatigue test data of pavement concrete. The static strength tests were carried out to check the compressive strength, flexural strength, and split tension strength at 56 days in order to minimize strength variation effect during test. The specimens were fabricated at twelves sections at a construction site of highway. The stress level and stress ratio of fatigue test were determined from static test results. The results are as follow: The flexural strength at 28 days mostly satisfied the criterion for design, but the compressive strength at 28 days were slightly below the criterion even though it satisfied at 56 days. The fatigue limit was 2 million cycles if the specimen was not failed to that cycles. The S-N curves were developed from the fatigue test results at each stress levels and each stress ratio. Then, the fatigue life of pavement concrete at a given stress level and fatigue strength of pavement concrete could be derived from these curves. Analysis using method No.2 was more acceptable because resulting of comparison and analysis using method No.2 was presented 2 sections were presented $R^2$ < 0.7, and other 2 sections were presented 0.7 < $R^2$ < 0.8, and the others 8 sections were $R^2{\geq}0.8$.

• International Journal of Automotive Technology
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• 제2권4호
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• pp.123-133
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• 2001

An important goal in diesel engine research is the development of a means to reduce the emission of oxides of nitrogen ($NO_x$) and soot particulate. A phenomenological model based on the multizone concept is used in the current paper to analyze and compare the effects of exhaust gas recirculation (EGR) and split fuel injection on emission from a compression-ignited, direct-injection engine. The present results show that $NO_x$ can be reduced with a minimum penalty of soot particle emission with cooled EGR. Compared with EGR, split fuel injection has a higher soot penalty at a given level of $NO_x$ reduction.