• Journal of Animal Environmental Science
• /
• v.18 no.3
• /
• pp.157-164
• /
• 2012

This study was conducted to investigate the effect of different farrowing space, narrow and wide, on the sow performances and piglet growth performances. The $1.5m^2$ of narrow farrowing space was determined as the size of farrowing crate. The $3.0m^2$ of wide space for farrowing sow was the same of farrowing pen to allow the behavior freedom of sow. Baby piglets in the wide farrowing space was protected from crushing of sow by installation of safety bar. The pregnant sows used in this study were stall-housed during gestation and moved to each farrowing spaces on 8 d before parturition. Feed intake, backfat thickness and body condition score of sow were not affected by both farrowing spaces. However, the changes in backfat thickness and body condition score between farrowing and weaning in wide farrowing space were lower (p<0.05) than in narrow farrowing space. The return to estrus of sow was remarkably decreased in wide farrowing space compared to sows in narrow farrowing space. The lower number of stillbirth and higher mortality of piglets were observed in wide farrowing space. From the results, although wide farrowing space could be practically acceptable in terms of sow performances, possible cause of mortality of piglets should be scrutinized through observation of piglet and sow behaviors.

• Journal of Korea Water Resources Association
• /
• v.46 no.1
• /
• pp.13-24
• /
• 2013

The main objective of this study was to develop a new regional frequency analysis model based on hierarchical Bayesian model that allows us to better estimate and quantify model parameters as well as their associated uncertainties. A Monte-carlo experiment procedure has been set up to verify the proposed regional frequency analysis. It was found that the proposed hierarchical Bayesian model based regional frequency analysis outperformed the existing L-moment based regional frequency analysis in terms of reducing biases associated with the model parameters. Especially, the bias is remarkably decreased with increasing return period. The proposed model was applied to six weather stations in Jeollabuk-do, and compared with the existing L-moment approach. This study also provided shrinkage process of the model parameters that is a typical behavior in hierarchical Bayes models. The results of case study show that the proposed model has the potential to obtain reliable estimates of the parameters and quantitatively provide their uncertainties.

• The Korean Journal of Financial Management
• /
• v.21 no.1
• /
• pp.1-32
• /
• 2004

This paper investigates the stock price and the volume behavior on the ex-dividend day using the December fiscal year firms listed on the Korea Stock Exchange from 1998 to 2000. Using the samples of voluntarily preannounced dividend-raying firms prior to the end of fiscal you, this study corrects the major limitations on previous studies -Kim, S. (1997) and Kim, S. (2003)- which were based on the perfect foresight assumption for firms' upcoming dividends. Also, this paper examines the information content of dividend more properly, since the preannounced date for the upcoming dividend payment is employed for the first time as the event date. Empirical results show that the announcement effects of cash and/or stock dividend is significant around the event date. The ex-dividend day stock returns are negative as expected for the samples of voluntarily preannounced cash dividend-paying firms.

• Journal of Christian Education in Korea
• /
• v.62
• /
• pp.285-311
• /
• 2020

Many people are suffering from the economic crisis and poverty that are deepening due to the recent spread of the COVID-19 epidemic. In this situation, this study focuses on the biblical Jubilee in order to seek how "Jubilee justice" can be realized in the modern context. The Law of Jubilee consists of four contents: the liberation of slaves, debt remission, land return and fallow. Ultimately it aims to prevent human slavery and preserve equality. Nevertheless, the thought of Jubilee has been distorted theologically and situationally, and as a result, it has been overlooked in the field of Christian education, and there is a limit in Christian practice for social justice. The thought of Jubilee, however, can be an alternative to overcome various problems of modern society such as the issue of the privatization of Christianity or the deepening of polarization caused by neoliberal globalization and can contribute positively to the practice of social justice. In other words, the thought of Jubilee can act as a biblical initiative in reforming wrong laws and establishing institutions for the poor on the institutional level; on the personal level, it can be a great motive in terms of the change of perception and the practice of the sharing economy. Jubilee education, which aims for Jubilee justice, helps to break the misconceptions and change the existing meaning perspectives on the basis of various interdisciplinary knowledge and supports social behavior for transforming social structure through activation of public opinion and fund raising at the practical level. Therefore, the learners of Christian education can play a public role in transforming the unjust society.

• Journal of the Korean Geographical Society
• /
• v.31 no.4
• /
• pp.648-661
• /
• 1996

The traditional von Thunen model has various shortcomings. Perhaps the greatest dificiency is the model's sole emphasis on the production side of the economy;that is, the agricultural markets are rarely closed for demand. In thes paoer a closed model for a three-activity, two-dimensional economy is developed. Equillibrium solutions are generated for prices, land areas, and outputs. Comparative static analysis then follows. Attention is next given to a maximum expected-return model under environmental uncertainty. Land uses for the traditional model and the closed model are then compared.

• Macromolecular Research
• /
• v.11 no.4
• /
• pp.207-223
• /
• 2003

For last five years, we are developing the novel local drug delivery devices using biodegradable polymers, especially polylactide (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) due to its relatively good biocompatibility, easily controlled biodegradability, good processability and only FDA approved synthetic degradable polymers. The relationship between various kinds of drug [water soluble small molecule drugs: gentamicin sulfate (GS), fentanyl citrate (FC), BCNU, azidothymidine (AZT), pamidronate (ADP), $1,25(OH)_2$ vitamin $D_3$, water insoluble small molecule drugs: fentanyl, ipriflavone (IP) and nifedipine, and water soluble large peptide molecule drug: nerve growth factor (NGF), and Japanese encephalitis virus (JEV)], different types of geometrical devices [microspheres (MSs), microcapsule, nanoparticle, wafers, pellet, beads, multiple-layered beads, implants, fiber, scaffolds, and films], and pharmacological activity are proposed and discussed for the application of pharmaceutics and tissue engineering. Also, local drug delivery devices proposed in this work are introduced in view of preparation method, drug release behavior, biocompatibility, pharmacological effect, and animal studies. In conclusion, we can control the drug release profiles varying with the preparation, formulation and geometrical parameters. Moreover, any types of drug were successfully applicable to achieve linear sustained release from short period ($1{\sim}3$ days) to long period (over 2 months). It is very important to design a suitable formulation for the wanting period of bioactive molecules loaded in biodegradable polymers for the local delivery of drug. The drug release is affected by many factors such as hydrophilicity of drug, electric charge of drug, drug loading amount, polymer molecular weight, the monomer composition, the size of implants, the applied fabrication techniques, and so on. It is well known that the commercialization of new drug needs a lot of cost of money (average: over 10 million US dollar per one drug) and time (average: above 9 years) whereas the development of DDS and high effective generic drug might be need relatively low investment with a short time period. Also, one core technology of DDS can be applicable to many drugs for the market needs. From these reasons, the DDS research on potent generic drugs might be suitable for less risk and high return.

• Korean Chemical Engineering Research
• /
• v.59 no.3
• /
• pp.417-428
• /
• 2021

The combustion characteristics of anthracite, which follow a complex process with low reactivity, must be considered through the dynamic behavior of circulating fluidized bed (CFB) boilers. In this study, computational fluid dynamics (CFD) simulation was performed to analyze the combustion characteristics of anthracite in a pilot scale 0.1 MW_th Oxy-fuel circulating fluidized bed (Oxy-CFB) boiler. The 0.1MW_th Oxy-CFB boiler is composed of combustor (0.15 m l.D., 10 m High), cyclone, return leg, and so on. To perform CFD analysis, a 3D simulation model reactor was designed and used. The anthracite used in the experiment has an average particle size of 1,070 ㎛ and a density of 2,326 kg/m³. The flow pattern of gas-solids inside the reactor according to the change of combustion environment from air combustion to oxygen combustion was investigated. At this time, it was found that the temperature distribution in air combustion and oxygen combustion showed a similar pattern, but the pressure distribution was lower in oxygen combustion. addition, since it has a higher CO₂ concentration in oxygen combustion than in air combustion, it can be expected that carbon dioxide capture will take place actively. As a result, it was confirmed that this study can contribute to the optimized design and operation of a circulating fluidized bed reactor using anthracite.

• Journal of the Korean Geotechnical Society
• /
• v.38 no.12
• /
• pp.45-65
• /
• 2022

In this paper, a diaphragm wall that supports soils and rock was modeled using FLAC, a finite difference analysis program, to evaluate the seismic behavior of temporary retaining structures in a deep excavation. The appropriateness of the numerical model was verified by comparing its results with those of the centrifuge test performed in a similar condition. The bending moment distribution along the diaphragm wall shows a very similar tendency, and the maximum acceleration obtained at the backfill and top of the wall shows a difference within 5%. Based on the developed model, a parametric study was conducted in various input earthquake, ground, and excavation conditions. The maximum structural forces and bending moment under earthquake loading were compared with the maximum values during excavation, from which the critical condition that requires a seismic design was roughly sorted out. The maximum bending moment of a wall that retains soil layers increased 17%. Particularly, the axial force of struts located in loose soils increased 32% under 100 years return period of an earthquake event, which strongly is estimated to require seismic design for structural safety.

• KIPS Transactions on Software and Data Engineering
• /
• v.3 no.10
• /
• pp.441-450
• /
• 2014

The stock market is constantly changing and sometimes the stock prices unaccountably plummet or surge. So, the stock market is recognized as a complex system and the change on the stock prices is unpredictable. Recently, many researchers try to understand the stock market as the network among individual stocks and to find a clue about the change of the stock prices from big data being created in real time from Internet. We focus on the correlation between the stock prices and the human interactions in Internet especially in the stock message boards. To uncover this correlation, we collected and investigated the articles concerning with 57 target companies, members of KOSPI200. From the analysis result, we found that there is no significant correlation between the stock prices and the article volume, but the strength of correlation between the article volume and the stock prices is relevant to the stock return. We propose a new method for recommending stock portfolio base on the result of our analysis. According to the simulated investment test using the article data from the stock message boards in 'Daum' portal site, the returns of our portfolio is about 1.55% per month, which is about 0.72% and 1.21% higher than that of the Markowitz's efficient portfolio and that of the KOSPI average respectively. Also, the case using the data from 'Naver' portal site, the stock returns of our proposed portfolio is about 0.90%, which is 0.35%, 0.40%, and 0.58% higher than those of our previous portfolio, Markowitz's efficient portfolio, and KOSPI average respectively. This study presents that collective human behavior on Internet stock message board can be much helpful to understand the stock market and the correlation between the stock price and the collective human behavior can be used to invest in stocks.

• Journal of dental hygiene science
• /
• v.10 no.6
• /
• pp.481-487
• /
• 2010

This study was conducted with 200 outpatients and inpatients of military hospitals around the northern region of Gyeonggi-Do. 182 questionnaires in 200 copies were returned, which meant that the return rate was 91%. 180 questionnaires were used for analysis because 2 questionnaires included untrustful responses. The questionnaires were filled by the subjects for 20 days from Dec. 1, 2008 to Dec. 20, 2008. First, in accordance with the examination on the awareness and knowledge on the dental caries, periodontal disease and oral health care, the awareness on the prevention of dental caries was 18.733 points in 25 full points. Second, for the examination on the oral health status according to the interest and education related to oral health care, the interest and oral health status showed the statistically significant relationship(P=0.0083). Third, in accordance with the analysis on the relationship between oral health status and awareness and knowledge on oral health care, for the awareness on the prevention of dental caries, the answer "Not healthy" was 19.188 points, the answer "Average" 18.210 points and the answer "Healthy" 18.971 points. In conclusion, the higher the interest on the education and oral health care was, the better the behavior for oral health care and oral health status were. As a result, the oral health care is essential for each individual to keep good health status. For keeping and deploying the best fighting power in the military and the country, the oral health program shall be pushed ahead as the key project to keep the good oral status of soldiers.