• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.19-25
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• 2007

In this study, a program based on the P-M interaction curve is developed to calculate the nominal strength of concrete pole. Using this, it is verified to compare with previous studies and the nominal strength$(M_n)$ of concrete pole is calculated. It is less than the rupture strength$(M_r)$ of the design standard. Thus, to increase nominal strength, several parameters are selected like as size of tension and reinforced bars, position of those, number of reinforcement bars, thickness of concrete pole, and diameter of it. The effects of those are analysed in the study. It is supposed that section of concrete pole are satisfied rupture strength.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.219-229
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• 2007

The results of the research in M&A firms in the KOSDAQ market are as follows. First, the effect of the M&A disclosure at the time of disclosure was that the positive (+) cumulative abnormal return (CAR) can be interpreted as an increase in the value of the firm; however, in the long run, firms which used the KOSDAQ index and the control firm, which did not use the index were found to have conflicting results. Second, the findings show that the rise in value of general firms resulting from a M&A were higher that those of venture firms. Third, in testing the performance extrapolation hypothesis, it was shown that the performance of "value" firms (firms with a high B/M ratio but poor performance in the past) was better after a M&A than those of the "glamour" firms and that the performance extrapolation hypothesis was substantiated. Fourth, it can be construed that a size effect in a merger exists. The CAR of the small firms surpasses those of large firms. Fifth, in verifying operating performance, most variables showed a positive (+) value at the time of M&A but showed a negative (-) value after a M&A. These results show that because on the Korean KOSDAQ market, M&A are approached from a financial rather than an economic aspect, it can be inferred that it lowers the firms value.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.260-270
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• 1996

Structure and dynamics of Pinus densiflora community in Mt. Kaya were studied to provide the information needed for management of Pinus densiflora forest in the southern inland of Korea. Stratification structure of Pinus densiflora community in the lower and middle slope consisted of tree layer(10~15m), subtree layer(4~10m), shrub layer(1~4m), and herb layer(below 1m), while in the rock zone of ridge and top area consisted of tree layer(7~10m), subtree layer(2~7m), shrub layer(1~2m), and herb layer(below 1m). According to the diameter distribution of tree species in Pinus densiflora community, secondary Pinus densiflora forest will gradually decline. Its forest may be replaced by Quercus mongolica, Quercus serrata, Carpinus laxiflora, C. cordata, and Fraxinus rhychophylla in the lower slope, and by Quercus mongolica in the middle slope. Pinus densiflora forest has its seedlings and saplings in ridge and top area, so it may be sustained. By taking cores from Pinus densiflora trees in research area, it could be obtained that in the lower and middle slope, age of Pinus densiflora forest was about 80~90 years old. When the age of its trees was about 72~80 years old, withering trees of standing dead occurred. Disturbance regime of Pinus densiflora community in Mt. Kaya consisted of standing dead, uprooting and limbfall, these were 70.6%, 17.6% and 11.8% respectively. It takes about 100~110 years for advance growth of Pinus densiflora in ridge and top area to reach tree layer. During the period, it has twice chances of disturbance in standing dead. Annual diameter growth of Pinus densiflora was 2.45~2.9mm in the lower and middle slope, while it was 1.75mm in ridge and top region, by measuring cores.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.341-346
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• 2002

This study is intended to check the possibility to estimate water content by heat-drying method with variation of W/C and slump. According to the results, in case of electric range method, when water content is less than 165kg/m$^3$ in mixture, it is estimated more and in more than 165kg/m$^3$, it is estimated less. It shows that water content in gas burner method is estimated less by about 2kg/m$^3$. Also, estimated water content shows difference by less than 12kg/m$^3$ in electric range method and by less than 12kg/m$^3$ in gas burner method. Therefore, it is thinked that if tested without error from preparing a sample to calculating amount of water, water content will be estimated exactly in the construction field.

• Explosives and Blasting
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• v.14 no.3
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• pp.3-9
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• 1996

The scope of this cable works was as follows, it was drilled two shafts, NO. 1 shaft (${\phi}6.8m{\times}31m$), NO.2 shaft (${\phi}6.8m{\times}33m$), ) and it was connected two shaft in Tunneling. The first, it was needed to investigate the surey of influenced of vibration and noise by blastig to near by housing structure. 2nd, it was essential to decide the boundary line of influenced for agriculture water and portable water, by draw down of underground water. Blasting works has been done successfully without any problem, but by draw down of underground water, with in 250m level from #1 shaft, agriculture well drilled 8 place and portable water well drilled 7 place for near by farmers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1279-1284
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• 2012

This study is about the change of coastline through using ASTER images. ASTER image is a sensor loaded in earth resources satellite shoot in Japan on Dec. 1999. It has 15m, 30m, 90m coastline, three sensors of VNIR, TIR and WIR, therefore it's possible to obtain more information on the Earth than the existing satellite images cause it contains various a wavelength range in spite of relatively economic image. The coastline is changed according to topography shape because it's strongly localized. Besides, it's one of the most important factors in MGIS(Marine Geographic Information System). Therefore, this study is accomplished by analysing variation after abstraction the coastline automatically by Vector Line from ASTER satellite images. The study result will be used as an important basic data when analysis the change of e coastline hereafter.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.177-195
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• 2005

The purpose of this study was to analyze the kinematic variables of ankle joints and EMG signal of the lower limbs muscle activity for the different walking speed. The subjects were 6 males of twenties. It was classified into three different walking speed-0.75m/s, 1.25m/s, 1.75m/s. The walking performances were filmed by high speed video camera and EMG signal was gained by ME3000P8 Measurement Unit. Tibialis anterior(TA), Gastrocnemius medial head(GM), Gastrocnemius lateral head(GL), Ssoleus(SO) were selected for the dorsiflexion and plantarflexion of the ankle joint. The result of this study were as follows: 1. In the gait cycle, The time parameters for the phases were showed significant difference without the terminal stance phase and terminal swing phase for the different walking speed. 2. The angle of ankle joint was no significant difference for each time point and MDF, MPF but increasing walking speed the angle had the increasing pattern slightly. 3. The angular velocity of ankle joint was showed the significant difference for LHC, RTO, RKC, LHU, MPF and MDF point along the walking speed. 4. TA was showed about 2-3 times muscle activity at the 1.75m/s than 1.25m/s in some phases. And it was showed the similar muscle activity between the 0.75m/s and 1.25m/s but, showed a little much muscle activity in the 0.75m/s. GM was showed about 2-3 times muscle activity in the 1.75m/s than 1.25m/s, and even much muscle activity at the 0.75m/s than 1.25m/s in some phases. GL was showed increasing pattern of muscle activity specially in the initial swing phase as the walking speed increased. SO was showed about 3 times muscle activity in the 1.75m/s than 1.25m/s during the plantarflexion of ankle joint. It was showed the similar muscle activity between the 0.75m/s and 1.25m/s but, showed a little much muscle activity in the 1.25m/s.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.759-765
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• 2004

The NCS inhibited the activity of glucosyltransferase which was produced by Streptococcus mutans JC-2, and the rate of inhibition at $100\muM<$ and $200\muM$ were 74.0% and 99.8%, respectively. It was stable in alkali condition, but unstable in acid condition. It was also stable up to $80^{\circ}C$. The kinetic study of the inhibition by NCS was carried out by Lineweaver-Burk plot and Dixon plot. It was non-competitive inhibition, determined by the two plots and $K_i$ and $K_i$ values were $15\muM$ and $19.3\muM$ respectively. The NCS did not show cytotoxicity against human gingival cells at $K_i$ ($15\muM$, $150\muM$, $1,500\mu$ M) concentrations. It had less cytotoxicity than chlohexidin, which has usually been used as the agent of anticaries. To evaluate the industrial applicability of the NCS, human pluck tooth was used. The inhibitory rates of tooth calcification and calcium ion elution by the NCS were 41 % and 2.5 times, respectively. These results suggested that NCS from Bacillus sp. S-1013 is an efficient anticaries agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.125-129
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• 1994

The acetone extracted pigment from the cell mass of Rhodophila globiformis DSM 161 was generally red. In a pH 5-6 condition, the color of pigment was red, while in p/h 7-9 condition it was yellowish red. The pigment was stable at pH range between 6.0-11.0 and below 4$0^{\circ}C$. In the presence of light and oxygen , the pigment was rapidly degraded and became unstable in the presence of metal ions such as Fe3++(1.0$\times$ 10-2M, 1.0$\times$10-3 M), Al3+ (1.0$\times$10-2 M, 1.0$\times$10-3 M) and Zn2+(1.0$\times$10-2 M). But in the presence of Zn2+ (1.0$\times$10-2M). But in the presence of Zn2+ (1.0$\times$10-3 M) it was very stable. Through visible absorption scanning ,it showed five sharp absorption peaks at 358 , 385, 494, 680 ad 748 nm with three shoulder peaks at 410, 466 and 522nm. On the results of TLC analysis , it was shown to be composed of seven color fractions.

• Journal of the Korea Institute of Building Construction
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• v.22 no.4
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• pp.415-423
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• 2022

As human factors are the most important cause of construction accidents, it is important to reduce human error in construction work to reduce accidents. However, the error forcing context in organizational situations acts as a factor behind human error. Therefore, fatal construction accidents were analyzed using the m-SHEL model, which can identify the factors behind human errors. Through such analysis, it was found that there are differences in the detailed factors behind human errors according to the type of fatal accidents in construction, This study is meaningful in that it confirmed through accident cases that it is important to understand and respond to organizational situations in order to reduce human error in construction work.