• Applied Microscopy
• /
• v.46 no.1
• /
• pp.27-31
• /
• 2016

It has been investigated what kind of characteristic X-ray in electron probe micro-analyzer (EPMA) is effective for the determination of compounds of Si series materials. After comparing the characteristic X-rays among the primary and secondary lines in $K_{\alpha}$ and $K_{\beta}$ obtained from the Si series standard samples, it was found that the secondary line of $K_{\alpha}$ exhibited the most informative spectrum although the intensity was considerably weak. As a result of analyzing the spectrum shapes of the Si series standard samples, the spectrum shape of the secondary line of $K_{\alpha}$ for SiC was different from those for other Si compounds. To grasp the characteristics of the shape, a line was perpendicularly drawn from the peak top to base line in order to divide a spectrum into two areas. The area ratio of right to left was defined to call as the asymmetry index here. As a result, the asymmetry index value of the SiC was greater than one, while those of other Si compounds were less than one. It was found from the EPMA analysis that identification of SiC became successful to distinguish from other Si compounds and this method was applicable for micro-sized compounds in a practical composite material.

• Journal of Pharmacopuncture
• /
• v.4 no.1
• /
• pp.103-104
• /
• 2001

This study was done to observe the effect on the local thermal changes of herbal acupuncture on D.I.T.I.. The objects of this study are as follows; If there are remarkable local thermal changes between pre and post herbal acupuncture therapy on D.I.T.I.or not. If there are those, We examine how long that changes are maintained, what the adequate interval is on herbal acupuncture therapy, and what the reaction in a .local or whole body are on that therapy Materials and Methods : To study the local thermal changes in herbal acupuncture therapy, D.I.T.I. was used. Determination of this analysis periods are pre and post-therapy(1 hour, 24hours, 48hours and 7days later). The study group was divided into three groups(comprised 23 students in oriental medical college, Woosuk University). One was NS(Normal Saline) group, another was CF(CARTHAMI SEMEN) group and the other was BU(FEL URSI + BENZOAR BOVIS) group. The Herbal Acupunture solution was injected 0.2ml divide into 0.05ml at tile P'ungmun(B12), P'yesu(B13), Pubun(B41), Paek'o(B42) 4 points. Then, in order to analyze the clinical form, we have observed response of 23 students whenever we checked the thermal changes of their after perfoming Results : The results were obtained as follows ; 1. There is no significant dermatothermal changes at NS group and CF group, but BU group have remarkable changes in 24, 48, 72 hours. 2. From post-therapy 1 hour to 48 hours, there is a significant change (P<0.01) at NS-BU group and CF-BU group, But there is none 7 days later. 3. In the analysis of whole or local body reaction, local pain appears at NS group(22%), CF group(11%), BU group(91%), discomfort reaction appears at CF group(14%), BU group(30%). BU groilp has feel vertigo(13%), drowsy (70%) and pain in action(52%). 4. In the analysis of the duration of physic진 reaction, BU group is most lately maintained. Conclusions : These results suggest that in the physical reaction of herbal acupuncture solutions, BU solution is more sensitive than CF solution or NS.

• School Mathematics
• /
• v.7 no.2
• /
• pp.103-121
• /
• 2005

This article compares and analyzes mathematics textbooks of North Korea, South Korea, China and Japan and draws meaningful ways for introducing the division algorithm of fractions. The analysis is based on the five contexts: 'measurement division', 'determination of a unit rate', 'reduction of the quantities in the same measure', 'division as the inverse of multiplication or Cartesian product', 'analogy with multiplication algorithm of fractions'. The main focus of the analysis is what context is used to introduce the algorithm and how much it can appeal to students. This analysis supports that there is a few differences of introducing methods the division algorithm of fractions among those countries and more meaningful way can be considered than ours. It finally suggests that we teach the algorithm in a way which can have students easily see the reason of multiplying the reciprocal of a divisor when they divide with fractions. For this, we need to teach the meaning of a reciprocal of fraction and consider to use the context of determination of a unit rate.

• Journal of Korean Society of Forest Science
• /
• v.75 no.1
• /
• pp.32-37
• /
• 1986

In order to get the fundamental information that could be useful to judge the potentiality of occurrence of rapid shallow landslide in the objective slope, factors selected on Jinhae regions in Korea, where many landslides were caused by heavy rainfall of daily 465 mm and hourly 52mm in August 1979, was carried out through the multiple statistics of quantification method (II) by the electronic computer. The net system with $2{\times}2cm$ unit mesh was overlayed with the contour map of scale 1:5000. 74 meshes of landslides and 119 meshes of non-landslide were sampled out to survey the state of vegetative cover and geomorphological conditions, those were divided into 6 items arid 27 categories. As a result, main factors that would lead to landslide were shown in order of vegetation, slope type, slope position, slope, aspect and numbers of stream. Particularly, coniferous forest of 10 years old, concave slope and foot of mountain were main factors making slope instability. On the contrary, coniferous forest of 20-30 years old, deciduous forest, convex slope and summit contributed to the stable against Landslide. The boundary value between two groups of existence and none of landslides was -0.123, and its prediction was 72%. It was well predicted to divide into two groups of them.

• The Korean Journal of Financial Management
• /
• v.24 no.2
• /
• pp.41-79
• /
• 2007

This study examines the expiration-day effects of stock index futures and options in the Korean stock market. The so-called 'expiration-day effects', which are the abnormal stock price movements on derivatives expiration days, arise mainly from cash settlement. Index arbitragers have to bear the risk of their positions unless they liquidate their index stocks on the expiration day. If many arbitragers execute large buy or sell orders on the expiration day, abnormal trading volumes are likely to be observed. If a lot of arbitragers unwind positions in the same direction, temporary trading imbalances induce abnormal stock market volatility. By contrast, if some information arrives at market, the abnormal trading activity must be considered a normal process of price discovery. Stoll and Whaley(1987) investigated the aggregate price and volume effects of the S&P 500 index on the expiration day. In a related study, Stoll and Whaley(1990) found a similarity between the price behavior of stocks that are subject to program trading and of the stocks that are not. Thus far, there have been few studies about the expiration-day effects in the Korean stock market. While previous Korean studies use the KOSPI 200 index data, we analyze the price and trading volume behavior of individual stocks as well as the index. Analyzing individual stocks is important for two reasons. First, stock index is a market average. Consequently, it cannot reflect the behavior of many individual stocks. For example, if the expiration-day effects are mainly related to a specific group, it cannot be said that the expiration of derivatives itself destabilizes the stock market. Analyzing individual stocks enables us to investigate the scope of the expiration-day effects. Second, we can find the relationship between the firm characteristics and the expiration-day effects. For example, if the expiration-day effects exist in large stocks not belonging to the KOSPI 200 index, program trading may not be related to the expiration-day effects. The examination of individual stocks has led us to the cause of the expiration-day effects. Using the intraday data during the period May 3, 1996 through December 30, 2003, we first examine the price and volume effects of the KOSPI 200 and NON-KOSPI 200 index following the Stoll and Whaley(1987) methodology. We calculate the NON-KOSPI 200 index by using the returns and market capitalization of the KOSPI and KOSPI 200 index. In individual stocks, we divide KOSPI 200 stocks by size into three groups and match NON-KOSPI 200 stocks with KOSPI 200 stocks having the closest firm characteristics. We compare KOSPI 200 stocks with NON-KOSPI 200 stocks. To test whether the expiration-day effects are related to order imbalances or new information, we check price reversals on the next day. Finally, we perform a cross-sectional regression analysis to elaborate on the impact of the firm characteristics on price reversals. The main results seem to support the expiration-day effects, especially on stock index futures expiration days. The price behavior of stocks that are subject to program trading is shown to have price effects, abnormal return volatility, and large volumes during the last half hour of trading on the expiration day. Return reversals are also found in the KOSPI 200 index and stocks. However, there is no evidence of abnormal trading volume, or price reversals in the NON-KOSPI 200 index and stocks. The expiration-day effects are proportional to the size of stocks and the nearness to the settlement time. Since program trading is often said to be concentrated in high capitalization stocks, these results imply that the expiration-day effects seem to be associated with program trading and the settlement price determination procedure. In summary, the expiration-day effects in the Korean stock market do not exist in all stocks, but in large capitalization stocks belonging to the KOSPI 200 index. Additionally, the expiration-day effects in the Korean stock market are generally due, not to information, but to trading imbalances.