• Title/Summary/Keyword: Short-term period

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Market Efficiency in Real-time : Evidence from the Korea Stock Exchange (한국유가증권시장의 실시간 정보 효율성 검증)

  • Lee, Woo-Baik;Choi, Woo-Suk
    • The Korean Journal of Financial Management
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    • v.26 no.3
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    • pp.103-138
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    • 2009
  • In this article we examine a unique data set of intraday fair disclosure(FD) releases to shed light on market efficiency within the trading day. Specifically, this paper analyze the response of stock prices on fair disclosure disseminated in real-time through KIND(Korea Investor's Network for Disclosure) on Korea stock exchange during the period from January 2003 to September 2004. We find that the prices of stock experiences a statistically and economically significant increase beginning seconds after the fair disclosure is initially announced and lasting approximately two minutes. The stock price responds more strongly to fair disclosure on smaller firm but the response to fair disclosure on the largest firm stock is more gradual, lasting five minutes. We also examine the profitability of a short-term trading strategy based on dissemination of fair disclosure. After controlling for trading costs we find that trader who execute a trade following initial disclosure generate negative profits, but trader buying stock before initial disclosure realize statistically significant positive profit after two minute of disclosure. Summarizing overall results, our evidence supports that security prices on Korea stock exchange reflects all available information within two minutes and the Korea stock market is semi-strongly efficient enough that a trader cannot generate profits based on widely disseminated news unless he acts almost immediately.

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Pain Relieving Effect of Intraoral Sucrose Replacement in Neonates (신생아의 통증완화를 위한 자당(sucrose) 경구투여 효과)

  • Yoon Hea-Bong
    • Child Health Nursing Research
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    • v.7 no.1
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    • pp.35-50
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    • 2001
  • The ability of neonates to perceive and react to pain, has been acknowledged recently. Recent researches have been shown that even short term pain can have lasting negative effects. We know that most of the anatomical pathway and neurotrans-mitter function necessary for pain perception are fully or nearly fully developed in the neonatal period. Many people are still reluctant to believe that pain felt by neonates may be as severe as that felt by older children or adults yet. The objective of the study is to assess and compare the analgesic effects of orally administered sucrose and pacifiers. And to determine the synergistic analgesic effects of sucrose and pacifiers. The tools for this study is Lawrence's NIPS (neonatal infant pain scale) with behavioural pain responses and index for pain physiological reponses as heart rate, respiratory rate and degree of SaO₂. The participants are 96 healthy infants of neonatal age 1-7days and randomised to receive heel prick before 2minutes to blood sampling and physiological test in Nursery of K Medical University Hospital on May-July, 2000. The experimental group assigned to one of three treatment groups : no treatment; a pacifier; placebo(2ml 25% sucrose). Collected data were analyzed with the SAS program using X²-test, ANOVA and Duncan's multiple range test as post hoc. The results were as follows. 1) Pain behaviour responses: The pain score of placebo group(2ml 25% sucrose) is lower than no treatment group and pacifier group significantly(P=.000). Placebo group is different from no treatment and pacifier group with Duncan's multiple range test. 2) Pain physiologic responses (1) heart rate: The heart rate of placebo group(2ml 25% sucrose) is different from that of no treatment group and pacifier group significantly(P=.000). The heart rate change of placebo group is less than the other groups. (2) respiratory rate: The respiratory rate of placebo group(2ml 25% sucrose) is different from that of no treatment group and pacifier group insignificantly (P=.2340). But, the respiratory rate of placebo group is lower than the other groups. (3) SaO₂: The SaO₂ score of placebo group(2ml 25% sucrose) is different from that of no treatment group and pacifier group insignificantly (P=.3265). But, the change of SaO₂ score of placebo group is less than the other groups. In conclusion, the sucrose placebo showed pain relief effect in behavior responses and less physiological responses. Accordingly, the sucrose placebo should be applied nursing intervention for simple pain management as heel prick.

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Evaluation of Properties of Sulfur-Oxidizing Bacteria Growth and Resistance to Biochemical Corrosion by Simulation Test (시뮬레이션 시험에 의한 황산화세균의 생장 특성 및 생화학적 부식 저항성 평가)

  • Kim, Gyu-Yong;Lee, Eui-Bae;Khil, Bae-Su;Lee, Seung-Hun
    • Journal of the Korea Concrete Institute
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    • v.20 no.4
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    • pp.495-502
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    • 2008
  • To analyze the growth of SOB(Thiobacillus novellus) and biochemical corrosion of concrete, simulation test method and device were developed, and basic conditions for SOB growth were established. Two types of simulation tests were conducted according to a transplant method and a concentration of $H_2SO_4$. As a result, the SOB growth in distinct manners and antibiosis of specimen were observed. In the case of the specimens indirectly transplanted with SOB through culture solution submersion at a hydrogen sulfide level of 120 ppm, the rapid activation of SOB and the resulting sulfuric acid production were observed. However, SOB were shown to grow rapidly and then die out in a relative short period of time. Meanwhile, in the case of the specimens directly transplanted with SOB at a hydrogen sulfide level of 50 ppm, the long-term growth of SOB was possible, but the production of sulfuric acid by SOB did not progress. In the case of the antibiotic metal-mixed specimens, SOB with destroyed cell membranes and internal organizations were observed.

Effect of Short-Term Feeding of Dietary Fiber Supplements on Glucose Metabolism in Subjects with Non-Insulin-Dependent Diabetes Mellitus (단기간의 식이섬유 첨가물의 섭취가 인슐린 비의존성 당뇨병 환자의 당질대사에 미치는 영향)

  • 이연경;이혜성;김보완
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.5
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    • pp.846-854
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    • 1996
  • High dietary fiber(DF) diets lower blood glucose and insulin requirements in diabetics. In this study we evaluated the effects of high dietary fiber(DF) food supplements on glucose metabolism in thirty-four subjects with non-insulin-dependent diabetes mellitus(NIDDM). The subjects were divided into three test groups. Each group's prescribed hospital diets were augmented by one of the three following DF supplements for two weeks: Soybean biscuits containing 5g of total DF-the control group(n=15); Biji biscuits containing 20g of total DF-the high insoluble DF group(n=9); and sea tangle biscuits containing 25g of total DF-the high soluble DF group(n=10). The mean daily DF intake of the subjects during the period were: $19.1\pm4.3g$ for the soybean control group; $32.5\pm4.1g$ for the Bijl group; and $38.1\pm5.5g$ for the sea tangle group. The supplementation of the Biji or sea tangle biscuits singnificantly lowered fasting serum glucose levels(p < 0.05) and resulted in the improvement of glucose tolerance. However, the secretions of insulin, C-peptide, and glucagon and Hb $A_{lc}$ concentration were not affected by the high fiber supplementary feeding for two weeks. The urinary excretion of glucose decreased remarkably after the addition of the DF supplements in all three groups(p<0.05). The results indicate that the supplementation of Biji or sea tangle bascuits possesses a beneficial effect on the improvement of glucose metabolism in subjects with NIDDM.

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Experimental Studies of the Short-Term Fluctuations of Net Photosynthesis Rate of Norway Spruce Needles under Field Conditions (야외조건하(野外條件下)에서 독일가문비(Picea abies Karst) 침엽(針葉)의 순(純) 광합성률(光合成率)의 단기(短期) 변화(變化)에 대한 실험적(實驗的) 연구(硏究))

  • Bolondinsky, V.;Oltchev, A.;Jin, Hyun O.;Joo, Yeong Teuk;Chung, Dong Jun
    • Journal of Korean Society of Forest Science
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    • v.88 no.1
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    • pp.38-46
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    • 1999
  • Canopy structure conductances of a Norway spruce forest in the Solling Hills(Central Germany) and Central Forest Biosphere Reserve(320km to the north-west from Moscow) were derived from LE(latent heat flux) and H(sensible heat flux) fluxes measured(by Eddy correlation technique and energy balance method) and modelled(by one dimensional non-steady-state) SVAT(soil-vegetation-atmosphere-transfer) model(SLODSVAT) using a rearranged Penman-Monteith equation("Big-leaf" approximation) during June 1996. They were compared with canopy stomatal conductances estimated by consecutive intergrating the stomatal conductance of individual needles over the whole canopy("bottom-up" approach) using SLODSVAT model. The result indicate a significant difference between the canopy surface conductances derived from measured and modelled fluxes("top-down" approach) and the stomatal conductances modelled by the SLODSVAT("bottom-up" approach). This difference was influenced by some nonphysiological factors within the forest canopy(e.g. aerodynamic and boundary layer resistances, radiation budget, evapotranspiration from the forest understorey). In general, canopy surface conductances derived from measured and modelled fluxes exceeded canopy stomatal conductance during the whole modelled period, The contribution of the understorey's evapotranspiration to the total forest evapotranspiration was small (up to 5-9% of the total LE flux) and was not depended on total radiation balance of forest canopy. Ignoring contribution of the understorey's evapotranspiration resulted in an overestimation of the canopy surface conductance for a spruce forest up to 2mm/s(about 10-15%).

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Geomorphological Processes of Yuga Alluvial Fan in Korea (유가 선상지의 지형 형성과정)

  • Lee, Gwang-Ryul;Cho, Young Dong
    • Journal of the Korean Geographical Society
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    • v.48 no.2
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    • pp.204-217
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    • 2013
  • This study shows the geomorphological processes of Yuga alluvial fan at Dalseong-gun, Daegu in Korea, based on characteristics of geomorphological surfaces, analysis of geomorphological deposits and OSL age dating. Alluvial fans of this area are classified into three surfaces(YG-F1, YG-F2, YG-F3) and were formed by the depositional processes resulting from the changes in hydraulic geometry of flowing water which was a stream flowing out of mountains debouched on to a plain, not by a sudden decrease in surface gradient of river bed. YG-F3 surface, about 110,000 yr B.P.(MIS 5.4), was formed as Yongri river deposited a lot of debris. This result was due to the process that the deposition took place actively with the upward of base level as the last interglacial period began. Later, the denudation of the river valley and geomorphological surface constantly occurred and the local and seasonal changes were found in precipitation and stream discharge with the beginning of the interstadial of the last glacial stages(MIS 3), leading to YG-F2 formed by debris flow, earth flow, mud flow and stream flow. Then, short-term climate changes and temporal climate events repeatedly caused aggradation and denudation over time and going through these processes, YG-F1 is believed to have been made by earth flow or mudflow during the last glacial maximum(MIS 2).

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A Retrospective study of the Cumulative Survival Rate and change of peri-implant marginal bone around implants associated with maxillary sinus augmentation (상악동 골 이식술을 동반하여 식립된 임플란트의 변연골변화와 생존률에 관한 후향적 연구)

  • Ryu, Hwa-Suk;Kim, Sun-Jong;Park, Eun-Jin;Kim, Myung-Rae
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.2
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    • pp.240-246
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    • 2009
  • Statement of problem: Insertion of endosseous implants in the atrophic maxilla is often complicated because of lack of supporting bone. Augmentation of the floor of the maxillary sinus with autogenous bone & bone substitute graft has been proven to be a reliable treatment modality, at least in the short term. The aim of this study is to evaluate the factors of implant survival rate associated with maxillary sinus lift with grafts. Material and methods: The sinus floor was augmented with bone grafts derived from modified Caldwell-luctechnique(71 subject, 93 sinus, 180 implants), the autogenous bone or autogenous+Bio-oss. Before implant installation the width and height of the alveolar crest were increased in the first stage procedure in 10 patients while in the other 61 patients augmentation and implant installation could be performed simultaneously width and height of the alveolar crest > 4 mm) or delayed installation. Results: In all case bone volume was sufficients for implant insertion. 14 of 180 inserted implants were lost during follow up and the healing period Patient received implant supported overdenture(5 patients) or fixed bridge(62 patients). Conclusion: Within the limit of the result of this study, we conclude that bone grafting of the floor of the maxillary sinus floor with bone for the insertion of implants might be a reliable treatment modality and the autogenous bone graft and delayed installation method might be the factors for good results.

Geospatial Assessment of Frost and Freeze Risk in 'Changhowon Hwangdo' Peach (Prunus persica) Trees as Affected by the Projected Winter Warming in South Korea: II. Freezing Risk Index Based on Dormancy Depth as a Proxy for Physiological Tolerance to Freezing Temperature (겨울기온 상승에 따른 복숭아 나무 '장호원황도' 품종의 결과지에 대한 동상해위험 공간분석: II. 휴면심도로 표현한 생리적 내동성에 근거한 동해위험지수)

  • Kim, Jin-Hee;Kim, Soo-Ock;Chung, U-Ran;Yun, Jin-I.;Hwang, Kyu-Hong;Kim, Jung-Bae;Yoon, Ik-Koo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.11 no.4
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    • pp.213-220
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    • 2009
  • In order to predict the risk of freeze injury for 'Changhowon Hwangdo' peach trees, we used the dormancy depth (i.e., the daily chill unit accumulation during the overwintering period) as a proxy for the short-term, physiological tolerance to freezing temperatures. A Chill-days model was employed and its parameters such as base temperature and chilling requirement were optimized for peach trees based on the 12 observational experiments during the 2008-2009 winter. The model predicted the flowering dates much closer to the observations than other models without considering dormancy depth, showing the strength of employing dormancy depth into consideration. To derive empirical equations for calculating the probabilistic freeze risk, the dormancy depth was then combined with the browning ratio and the budburst ratio of frozen peach fruit branches. Given the exact date and the predicted minimum temperature, the equations calculate the probability of freeze damages such as a failure in budburst or tissue browning. This method of employing dormancy depth in addition to freezing temperature would be useful in locating in advance the risky areas of freezing injury for peach trees production under the projected climate change.

Determination of Soil Nitrogen Supplying Capacity Using Pepsin Digestibility (Pepsin 분해방법을 이용한 토양의 질소 공급력 결정)

  • Kim, Yoo-Hak;Kim, Sun-Kwan;Zhang, Yong-Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.38 no.5
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    • pp.253-258
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    • 2005
  • It is necessary to determine a nitrogen supplying capacity (NSC) of soil for sustainable agriculture. NSC has been decided by directly detecting N mineralization potential (NMP) and inorganic nitrogen or by indirectly approximating from organic matter and chemical properties of soil. NMP is best method for NSC but it takes long period. A study was conducted to find a short-term incubation method using pepsin through 1) determining NMP of 3 upland and 3 paddy soils, 2) establishing analytical condition of pepsin digestion by comparing to NMP, 3) validating with relations to N requirements for maximum yield of rice. NMPs of 6 soils were ranges from $63mg\;N\;kg^{-1}$ to $156mg\;N\;kg^{-1}$. The pepsin digestion method of soil nitrogen was established by determining amino nitrogen from digesting 5 g of soil for 30 minutes by 0.02% pepsin. This method was so highly correlated with a maximum rate of nitrogen fertilizer that it could be used for determining NSC in paddy soil.

Water Supply forecast Using Multiple ARMA Model Based on the Analysis of Water Consumption Mode with Wavelet Transform. (Wavelet Transform을 이용한 물수요량의 특성분석 및 다원 ARMA모형을 통한 물수요량예측)

  • Jo, Yong-Jun;Kim, Jong-Mun
    • Journal of Korea Water Resources Association
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    • v.31 no.3
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    • pp.317-326
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    • 1998
  • Water consumption characteristics on the northern part of Seoul were analyzed using wavelet transform with a base function of Coiflets 5. It turns out that long term evolution mode detected at 212 scale in 1995 was in a shape of hyperbolic tangent over the entire period due to the development of Sanggae resident site. Furthermore, there was seasonal water demand having something to do with economic cycle which reached its peak at the ends of June and December. The amount of this additional consumption was about $1,700\;\textrm{cm}^3/hr$ on June and $500\;\textrm{cm}^3/hr$ on December. It was also shown that the periods of energy containing sinusoidal component were 3.13 day, 33.33 hr, 23.98 hr and 12 hr, respectively, and the amplitude of 23.98 hr component was the most humongous. The components of relatively short frequency detected at $2^i$[i = 1,2,…12] scale were following Gaussian PDF. The most reliable predictive models are multiple AR[32,16,23] and ARMA[20, 16, 10, 23] which the input of temperature from the view point of minimized predictive error, mutual independence or residuals and the availableness of reliable meteorological data. The predicted values of water supply were quite consistent with the measured data which cast a possibility of the deployment of the predictive model developed in this study for the optimal management of water supply facilities.

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