• Journal of Navigation and Port Research
• /
• v.26 no.1
• /
• pp.106-111
• /
• 2002

The estimation of pile bearing capacity is important since the design details are determined from the result. There are numerous ways of determining the pile design load, but only few of them are chosen in the actual design. According to the recent investigation in Korea, the formulas proposed by Meyerhof based on the SPT N values are most frequently chosen in the design stage. In the study, various static and dynamic formulas have been used in predicting the allowable bearing capacity of a pile. Further, the reliability of these formulas has been verified by comparing the perdicted values with the static and dynamic load test measurements. Also, in most cases, these methods of pile bearing capacity determination do not take the time effect consideration, the actual allowable load as determined from pile load test indicates severe deviation from the design value. The principle results of this study are summarized as follows : As a result of estimate the reliability in criterion of the Davisson method, t was showed that Terzaghi & Peck >Chin>Meyerhof > Modified Meyerhof method was the most reliable method for the prediction of bearing capacity. Comparisons of the various pile-driving formulas showed that Modified Engineering News was the most reliable method. However, a significant error happened between dynamic bearing capacity equation was judged that uncertainty of hammer efficiency, characteristics of variable, time effect etc... was not considered. As a result of considering time effect increased skin friction capacity higher than end bearing capacity. It was found out that it would be possible to increase the skin friction capacity 1.99 times higher than a driving. As a result of considering 7 day's time effect, it was obtained that Engineering news, Modified Engineering News, Hiley, Danish, Gates, CAPWAP(CAse Pile Wave Analysis Program) analysis for relation, repectively, $Q_{u(Restrike)} / Q_{u(EOID)} = 0.98t_{0.1}$ , $0.98t_{0.1}$, $1.17t_{0.1}$, $0.88t_{0.1}$, $0.89t_{0.1}$, $0.97t_{0.1}$.

• The Korean Journal of Pharmacology
• /
• v.21 no.2
• /
• pp.128-141
• /
• 1985

To investigate the influence of phenobarbital sodium on the action of morphine and on the diurnal rhythms of both opiate receptor binding and ${\beta}-endorphin$ contents, the amount of specifically bound $(^3H)$-morphine and immunoreactive ${\beta}-endorphin$ were measured in the midbrain of phenobarbital-treated rats at 4h intervals in a day. Rats were housed and adapted to a controlled cycle of either 12 h light-12 h dark or 24 h constant dark. After 3 weeks of adaptation, 0.5 ml of physiological saline or phenobarbital sodium (20mg/kg/day, i.p.) were administered twice a day for 2 weeks. Highly significant diurnal rhythms of opiate receptor binding and ${\beta}-endorphin$ were present in rat midbrain. In control group, the peak of maximum $(^3H)$-morphine binding was observed at 22:00 h, whereas the peak of ${\beta}-endorphin$ content was found at 06:00 h. Even in the absence of time cues these diurnal rhythms persisted, but they were highly modified with respect to the wave form as well as differences in the timing of peak and nadir. In the phenobarbital-treated group, these diurnal rhythms were also modified in shape, phase and amplitude, as well as in timing of peak and nadir. In this group, 24 h mean of opiate receptor binding was significantly decreased, while the 24 h mean level of ${\beta}-endorphin$ content was highly increased. However, Kd values in all experimental groups did not change. This indicates that differences in binding were not due to changes in the affinity, but in the number of binding sites. Statistical analysis of regression line indicates that changes of receptor binding were closely correlated with the changes of ${\beta}-endorphin$ content. These results suggest that phenobarbital may influence the action of morphine by changing the number of opiate receptors and that the modification of diurnal rhythm of opiate receptor by the agent is possibly due to changes of ${\beta}-endorphin$ content.

• Journal of Chest Surgery
• /
• v.31 no.1
• /
• pp.20-27
• /
• 1998

It is well known that troponin T(below TnT) is present in the myocardial cells and released during myocardial damage, so it`s very specific enzyme to myocardium. Availability of cardiac specific TnT in assessing perioperatively myocardial damage was evaluated from 34 open heart surgery patients. They consisted of 11 ischemic heart, 13 acquired valvular heart and 10 congenital heart cases. Patients were divided into two groups, group A(patients with myocardial damage) and group B(patients without myocardial damage), according to the symptom of chest pain suspecting angina and the ECG findings of ST segment and T wave changes which show myocardial ischemia and injury. Serum TnT levels were measured by enzyme immunoassay method preoperatively, immediately postoperatively, postoperative day 1, day 2, day 3, and day 7. We observed and analyzed the changes of serum TnT levels in two groups and compared the serum TnT levels with CK-MB levels measured at the same time. In group A, serum TnT levels showed 1.37$\pm$0.26$\mu$g/L, 3.16$\pm$0.66$\mu$g/L, 2.39$\pm$0.74$\mu$g/L, 2.49$\pm$0.76$\mu$g/L, and 1.23$\pm$0.60$\mu$g/L, immediate postoperatively, postoperatively day1, day2, day3, and day7, respectively. It was observed there were significant differences compared with those of group B(0.38$\pm$0.04$\mu$g/L, 0.34$\pm$0.05$\mu$g/L, 0.25$\pm$0.03$\mu$g/L, 0.24$\pm$0.04$\mu$g/L, and 0.11$\pm$0.03$\mu$g/L) during identical periods(P<0.01). Serum CK-MB level in group A significantly elevated to 145.04$\pm$35.08 IU/L on the postoperative day 1 compared to group B(31.28$\pm$5.87 IU/L, P<0.05), However, it stiffly decreased from day 2 and returned to preoperative level at day 3. When serum TnT level more than 1.0$\mu$g/L is thought to reflect myocardial damage, serum TnT had 100% of sensitivity and 87% of specificity in diagnosing the postoperative myocardial damage(p<0.01). I conclusion, serum TnT levels increased significantly at very early stage of myocardial damage and persisted much longer period than CK-MB. This suggests that serum TnT has more advantage and availability in assessing the perioperatively myocardial damage than any other tests.

• Sleep Medicine and Psychophysiology
• /
• v.20 no.2
• /
• pp.75-81
• /
• 2013

Objectives: There are a lot of studies that analyze the interaction between the emotion of disgust and the functional brain images using fMRI and PET. But studies using sLORETA (standardized low resolution brain electromagnetic tomography) almost do not exist. The aim of this research is to explore the relationship of the emotion of disgust and the cortical activation using sLORETA analysis. Methods: Forty five healthy young adults ($27.1{\pm}2.6$ years) participated in the study. While they were watching 4 neutral images and 4 disgusting images associated with mutilation selected from the international affective picture system (IAPS), participants' EEGs were taken for 30 seconds per one picture. Through these obtained EEG data, sLORETA analysis was performed to compare EEGs associated with neutral and negative images. Results: During looking for visual disgusting stimulus, all participants reported unpleasantness, arousal and stress. In sLORETA analysis, the decrease of current density in theta wave was shown at left frontal superior gyrus (BA10) and middle gyrus (BA10, 11). This voxel cluster consists of a total of 11 voxels and the threshold of t value indicating statistically significant decreases in the current density (p<0.05) was -1.984. There were no differences between male and female in the degree of being disgusted by the stimuli. Conclusion: This finding may suggest that the activation of dorsolateral prefrontal cortex might be associated with regulating disgust emotion.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.5
• /
• pp.628-636
• /
• 2018

Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.

• Korean Journal of Family Social Work
• /
• no.54
• /
• pp.297-331
• /
• 2016

The purpose of this study was to examine the mediating roles of neglectful rearing attitudes and mental health in the relationship between economic status of single-parent famillies and school adjustment, and the differences between single-parent and two-parent families, using structural equation modeling. Data were obtained from the Middle School 1 Panel(third-wave) of the Korean Child and Youth Panel Survey 2010. This study selected 2,195 middle school 3th-grade students (249 from single-parent families and 1,946 from two-parent families). Data were examined with structural equation modeling and multi-group analysis using AMOS 21.0, and mediating effects were tested using the Sobel test. The results were as follows; First, the single-parent children reported lower levels of economic status and school adjustment, and higher levels of neglectful rearing attitudes than the two-parent children. Second, multi-group analysis showed a statistically significant difference between single-parent and two-parent in structural equation modeling. Economic status of two-parent famillies affected school adjustment of children, but economic status of single-parent famillies did not affect school adjustment of children. Third, as a result of examining for total effect, the variable that most influenced school adjustment of children was neglectful rearing attitudes. Fourth, neglectful rearing attitudes and mental health did play a mediating role in the relationship between economic status and school adjustment in case of two-parent famillies, but neglectful rearing attitudes and mental health did not play a mediating role in case of single-parent famillies. Based on the result, this study stressed the following; First, the study suggested that problem of the single-parent famillies supporting standard which is concentrated on the low income single-parent famillies. Second, the study proposed multifaceted support measures which reflects characteristics of single-parent famillies to increase school adjustment of the single-parent children.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2014.10a
• /
• pp.1-24
• /
• 2014

This study uses geo-spatial crop modeling to quantify the biophysical impact of weather extremes. More specifically, the study analyzes the weather extreme which affected maize production in the USA in 2012; it also estimates the effect of a similar weather extreme in 2050, using future climate scenarios. The secondary impact of the weather extreme on food security in the developing world is also assessed using trend analysis. Many studies have reported on the significant reduction in maize production in the USA due to the extreme weather event (combined heat wave and drought) that occurred in 2012. However, most of these studies focused on yield and did not assess the potential effect of weather extremes on food prices and security. The overall goal of this study was to use geo-spatial crop modeling and trend analysis to quantify the impact of weather extremes on both yield and, followed food security in the developing world. We used historical weather data for severe extreme events that have occurred in the USA. The data were obtained from the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA). In addition we used five climate scenarios: the baseline climate which is typical of the late 20th century (2000s) and four future climate scenarios which involve a combination of two emission scenarios (A1B and B1) and two global circulation models (CSIRO-Mk3.0 and MIROC 3.2). DSSAT 4.5 was combined with GRASS GIS for geo-spatial crop modeling. Simulated maize grain yield across all affected regions in the USA indicates that average grain yield across the USA Corn Belt would decrease by 29% when the weather extremes occur using the baseline climate. If the weather extreme were to occur under the A1B emission scenario in the 2050s, average grain yields would decrease by 38% and 57%, under the CSIRO-Mk3.0 and MIROC 3.2 global climate models, respectively. The weather extremes that occurred in the USA in 2012 resulted in a sharp increase in the world maize price. In addition, it likely played a role in the reduction in world maize consumption and trade in 2012/13, compared to 2011/12. The most vulnerable countries to the weather extremes are poor countries with high maize import dependency ratios including those countries in the Caribbean, northern Africa and western Asia. Other vulnerable countries include low-income countries with low import dependency ratios but which cannot afford highly-priced maize. The study also highlighted the pathways through which a weather extreme would affect food security, were it to occur in 2050 under climate change. Some of the policies which could help vulnerable countries counter the negative effects of weather extremes consist of social protection and safety net programs. Medium- to long-term adaptation strategies include increasing world food reserves to a level where they can be used to cover the production losses brought by weather extremes.

• Journal of the Korean earth science society
• /
• v.42 no.5
• /
• pp.479-495
• /
• 2021

This study investigates the synoptic (patterns of southern highs, northern lows, and lows rapidly developed by tropopause folding), thermodynamic, and kinematic characteristics of a strong wind that occurred in the Yeongdong region of South Korea on March 18-20, 2020. To do so, we analyzed data from an automatic weather station (AWS), weather charts, the European Centre for Medium-range Weather Forecasts (ECMWF) reanalysis, rawinsonde, and windprofiler radars. The daily maximum instantaneous wind speed, exceeding 20 m s^-1, was observed at five weather stations during the analysis period. The strongest instantaneous wind speed (27.7 m s^-1) appeared in the Daegwallyeong area. According to the analysis of weather charts, along with the arrangement of the north-south low-pressure line, the isobars were moved to the Yeongdong area. It showed a sine wave shape, and a strong wind developed owing to the strong pressure gradient. On March 19, in the northern part of the Korean Peninsula, with a drop in atmospheric pressure of 19 hPa or more within one day, a continuous strong wind was developed by the synoptic structure of the developing polar low. In the adiabatic chart observed in Bukgangneung, the altitude of the inversion layer was located at an altitude of approximately 1-3 km above the mountaintop, along with the maximum wind speed. We confirmed that this is consistent with the results of the vertical wind field analysis of the rawinsonde and windprofiler data. In particular, based on the thermodynamic and kinematic vertical analyses, we suggest that strong winds due to the vertical gradient of potential temperature in the lower layer and the development of potential vorticity due to tropopause folding play a significant role in the occurrence of strong winds in the Yeongdong region.

• Korea Real Estate Review
• /
• v.28 no.1
• /
• pp.79-90
• /
• 2018

The purpose of this study was to estimate the pricing factors of residential lands in new cities by estimating the pricing model of residential lands. For this purpose, hedonic equations for each quantile of the conditional distribution of land prices were estimated using quantile regression methods and the sale price date of Jangyu New Town in Gimhae. In this study, a quantile regression method that models the relation between a set of explanatory variables and each quantile of land price was adopted. As a result, the differences in the effects of the characteristics by price quantile were confirmed. The number of years that elapsed after the completion of land construction is the quadratic effect in the model because its impact may give rise to a non-linear price pattern. Age appears to decrease the price until certain years after the construction, and increases the price afterward. In the estimation of the quantile regression, land age appears to have a statistically significant impact on land price at the traditional level, and the turning point appears to be shorter for the low quantiles than for the higher quantiles. The positive effects of the use of land for commercial and residential purposes were found to be the biggest. Land demand is preferred if there are more than two roads on the ground. In this case, the amount of sunshine will improve. It appears that the shape of a square wave is preferred to a free-looking land. This is because the square land is favorable for development. The variables of the land used for commercial and residential purposes have a greater impact on low-priced residential lands. This is because such lands tend to be mostly used for rental housing and have different characteristics from residential houses. Residential land prices have different characteristics depending on the price level, and it is necessary to consider this in the evaluation of the collateral value and the drafting of real estate policy.

• Journal of Intelligence and Information Systems
• /
• v.25 no.2
• /
• pp.99-122
• /
• 2019

According to the recent IDC (International Data Corporation) report, as from 2025, the total volume of data is estimated to reach ten times higher than that of 2016, corresponding to 163 zettabytes. then the main body of generating information is moving more toward corporations than consumers. So-called "the wave of Big-data" is arriving, and the following aftermath affects entire industries and firms, respectively and collectively. Therefore, effective management of vast amounts of data is more important than ever in terms of the firm. However, there have been no previous studies that measure the effects of big data investment, even though there are number of previous studies that quantitatively the effects of IT investment. Therefore, we quantitatively analyze the Big-data investment effects, which assists firm's investment decision making. This study applied the Event Study Methodology, which is based on the efficient market hypothesis as the theoretical basis, to measure the effect of the big data investment of firms on the response of market investors. In addition, five sub-variables were set to analyze this effect in more depth: the contents are firm size classification, industry classification (finance and ICT), investment completion classification, and vendor existence classification. To measure the impact of Big data investment announcements, Data from 91 announcements from 2010 to 2017 were used as data, and the effect of investment was more empirically observed by observing changes in corporate value immediately after the disclosure. This study collected data on Big Data Investment related to Naver 's' News' category, the largest portal site in Korea. In addition, when selecting the target companies, we extracted the disclosures of listed companies in the KOSPI and KOSDAQ market. During the collection process, the search keywords were searched through the keywords 'Big data construction', 'Big data introduction', 'Big data investment', 'Big data order', and 'Big data development'. The results of the empirically proved analysis are as follows. First, we found that the market value of 91 publicly listed firms, who announced Big-data investment, increased by 0.92%. In particular, we can see that the market value of finance firms, non-ICT firms, small-cap firms are significantly increased. This result can be interpreted as the market investors perceive positively the big data investment of the enterprise, allowing market investors to better understand the company's big data investment. Second, statistical demonstration that the market value of financial firms and non - ICT firms increases after Big data investment announcement is proved statistically. Third, this study measured the effect of big data investment by dividing by company size and classified it into the top 30% and the bottom 30% of company size standard (market capitalization) without measuring the median value. To maximize the difference. The analysis showed that the investment effect of small sample companies was greater, and the difference between the two groups was also clear. Fourth, one of the most significant features of this study is that the Big Data Investment announcements are classified and structured according to vendor status. We have shown that the investment effect of a group with vendor involvement (with or without a vendor) is very large, indicating that market investors are very positive about the involvement of big data specialist vendors. Lastly but not least, it is also interesting that market investors are evaluating investment more positively at the time of the Big data Investment announcement, which is scheduled to be built rather than completed. Applying this to the industry, it would be effective for a company to make a disclosure when it decided to invest in big data in terms of increasing the market value. Our study has an academic implication, as prior research looked for the impact of Big-data investment has been nonexistent. This study also has a practical implication in that it can be a practical reference material for business decision makers considering big data investment.