• The Korean Journal of Pharmacology
• /
• v.28 no.1
• /
• pp.1-9
• /
• 1992

Catecholamines, serotonin and their metabolites were measured in the posterior hypothalamus of urethane-anesthetized normotensive Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) using brain microdialysis which is a recently developed experimental method to measure the release of neurotransmitters and their metabolites at the localized brain area in vivo. Microdialysis probe was implanted stereotaxically to the rat posterior hypothalamus and perfused by Ringer's solution. Monoamines and their metabolites were quantified by reverse phase high performance liquid chromatography with electrochemical detection. In vitro recovery test of microdialysis showed that there exist inverse relationship between the perfusion flow rate and the relative recovery of neurochemical compounds. The estimated extracellular concentration of dopamine was about 32 nM, of norepinephrine 50 nM, of epinephrine 50 nM, of serotonin 73 nM, of 3, 4-dihydroxyphenylacetic acid (DOPAC) 281 nM, of homovanillic acid (HVA) 181 nM, and of 5-hydroxyindoleacetic acid (5HIAA) 3767 nM in the hypothalamic perfusate of the normotensive rat. There was no difference in the basal level of monoamines between the SHR and the WKY. In contrast, the level of DOPAC, HVA and 5HIAA in SHR was higher than that in the WKY, This study demonstrated that the microdialysis technique should be an applicable tool for in vivo measurement of central neurochemical substances.

• Journal of KIISE:Software and Applications
• /
• v.34 no.12
• /
• pp.1045-1055
• /
• 2007

Latent topic models are statistical models which automatically captures salient patterns or correlation among features underlying a data collection in a probabilistic way. They are gaining an increased popularity as an effective tool in the application of automatic semantic feature extraction from text corpus, multimedia data analysis including image data, and bioinformatics. Among the important issues for the effectiveness in the application of latent topic models to the massive data set is the efficient learning of the model. The paper proposes an accelerated learning technique for PLSA model, one of the popular latent topic models, by an incremental EM algorithm instead of conventional EM algorithm. The incremental EM algorithm can be characterized by the employment of a series of partial E-steps that are performed on the corresponding subsets of the entire data collection, unlike in the conventional EM algorithm where one batch E-step is done for the whole data set. By the replacement of a single batch E-M step with a series of partial E-steps and M-steps, the inference result for the previous data subset can be directly reflected to the next inference process, which can enhance the learning speed for the entire data set. The algorithm is advantageous also in that it is guaranteed to converge to a local maximum solution and can be easily implemented just with slight modification of the existing algorithm based on the conventional EM. We present the basic application of the incremental EM algorithm to the learning of PLSA and empirically evaluate the acceleration performance with several possible data partitioning methods for the practical application. The experimental results on a real-world news data set show that the proposed approach can accomplish a meaningful enhancement of the convergence rate in the learning of latent topic model. Additionally, we present an interesting result which supports a possible synergistic effect of the combination of incremental EM algorithm with parallel computing.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.2
• /
• pp.405-412
• /
• 2018

The budget is an essential tool for the systematic management of the organizational performance and for diagnosing the status of an organization. Effective budget execution is important to hospital management due to the nonprofit nature of hospitals. On the other hand, there are few studies regarding the budgetary slack of hospitals in Korea. The purpose of this study was to investigate the effects of the university hospital budgeting system characteristics on the budgetary slack. For this purpose, the data from 118 staff of a university hospital located in Seoul were collected by self-administered surveys. Frequency analysis, correlation analysis, and multiple regression analysis were carried out using Stata Ver. 14. The main results of this study were as follows. First, information asymmetry has a positive influence on the budgetary slack. Second, budget feedback and budget motivation have a negative effect on the budgetary slack. These findings suggest that the sharing of budget-related information among hospital staff is important for efficient hospital management. In addition, it is necessary to establish ways to enhance the feedback and motivation in budgetary activities for managing the budgetary slack systematically. The major strength of this study is that it draws attention to research concerning the budgetary slack of hospitals in the absence of research on the budgetary slack. The significance of this study was to provide an empirical basis for improving the efficiency of hospital management.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.11
• /
• pp.817-825
• /
• 2017

The AC-common bus microgrid system can overcome several weaknesses of the DC microgrid system by interconnecting the DC/AC inverters used for renewable energy with an AC network. Nevertheless, the unbalanced loads inherent in the electric power systems of island and small communities can deteriorate the performance of the AC microgrid system. This is because of the limited voltage regulation capability and mixed power flow in the voltage source inverter. In order to overcome the unbalanced load condition, this paper proposes a voltage and current control algorithm for the 4-leg inverter based on the single phase d-q control method, as well as the modeling of the voltage controller using Matlab/Simulink S/W. From the S/W simulation and experiment of the 250KW proto-type inverter, it is confirmed that the proposed algorithm is a useful tool for the design and operation of the AC microgrid system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.12
• /
• pp.7364-7371
• /
• 2014

Construction post-evaluation (CPE) boosts the efficiency of public construction projects by assessing the performance results of public construction projects and using the results to pursue similar projects. This evaluation comprehensively analyzes and assesses the planning of construction work, the estimated and actual construction costs, the construction period, the demand for construction projects, and the effects of construction projects after the construction work to ensure efficiency. The data was used to prevent lax project execution and enhance the quality and efficiency of similar construction projects. On the other hand, CPE results information must be managed systematically to refer to and use CPE data in similar construction projects. Therefore, in this study, the CPE system was developed as a measure of the systematic and comprehensive management and use of the CPE results information of individual ordering agencies. Therefore, the groundwork was laid for the assurance of quality enhancement and efficient project execution in public construction projects. This system is expected to serve as a useful tool for comprehensively analyzing and assessing construction works.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.7
• /
• pp.481-491
• /
• 2016

This study analyzed the customer's revisit concepts and storytelling by restaurant customers to identify the elements that can attract the attention of customers. The restaurant concept or advertising, restaurant decor will also have to change to emphasize the comparative advantage of the features in the menu of a restaurant or other restaurants / service that tells a story. Membership cards or money, or the same convenience and use of the restaurant non-monetary 'transition cost' can compensate for the negative emotions and low satisfaction level of restaurant customers and help them choose to revisit the restaurant. Therefore, if such a transition takes full account of the effects of the cost to the customer, it can be used as an effective means. In class restaurants, such as the food and customer service, the increased levels of the restaurant atmosphere and empirical elements, such as store concept and physical environment, can improve the positive consumer sentiment, strengthen the customer satisfaction and have a positive effect on the customers' revisit intention. It is also important to improve the level of visual texture using light. In addition, positive consumer sentiment can be induced using the store concept, the physical environment, and experiential elements. In other words, membership cards, mileage points, and various financial and non-financial inducements as a marketing tool will have a positive impact on the customer's revisit intention.

• Journal of Distribution Science
• /
• v.11 no.2
• /
• pp.45-55
• /
• 2013

Purpose - The development and implementation of OSS (Open Source Software) led to a dramatic change in corporate IT infrastructure, from system server to smart phone, because the performance, reliability, and security functions of OSS are comparable to those of commercial software. Today, OSS has become an indispensable tool to cope with the competitive business environment and the constantly-evolving IT environment. However, the use of OSS is insufficient in small and medium-sized companies and software houses. This study examines the need for OSS Intermediaries in the Software Distribution Channel. It is expected that the role of the OSS Intermediary will be reduced with the improvement of the distribution process. The purpose of this research is to prove that OSS Intermediaries increase the efficiency of the software distribution market. Research design, Data, and Methodology - This study presents the analysis of data gathered online to determine the extent of the impact of the intermediaries on the OSS market. Data was collected using an online survey, conducted by building a personal search robot (web crawler). The survey period lasted 9 days during which a total of 233,021 data points were gathered from sourceforge.net and Apple's App store, the two most popular software intermediaries in the world. The data collected was analyzed using Google's Motion Chart. Results - The study found that, beginning 2006, the production of OSS in the Sourceforge.net increased rapidly across the board, but in the second half of 2009, it dropped sharply. There are many events that can explain this causality; however, we found an appropriate event to explain the effect. It was seen that during the same period of time, the monthly production of OSS in the App store was increasing quickly. The App store showed a contrasting trend to software production. Our follow-up analysis suggests that appropriate intermediaries like App store can enlarge the OSS market. The increase was caused by the appearance of B2C software intermediaries like App store. The results imply that OSS intermediaries can accelerate OSS software distribution, while development of a better online market is critical for corporate users. Conclusion - In this study, we analyzed 233,021 data points on the online software marketplace at Sourceforge.net. It indicates that OSS Intermediaries are needed in the software distribution market for its vitality. It is also critical that OSS intermediaries should satisfy certain qualifications to play a key role as market makers. This study has several interesting implications. One implication of this research is that the OSS intermediary should make an effort to create a complementary relationship between OSS and Proprietary Software. The second implication is that the OSS intermediary must possess a business model that shares the benefits with all the participants (developer, intermediary, and users).The third implication is that the intermediary provides an OSS of high quality like proprietary software with a high level of complexity. Thus, it is worthwhile to examine this study, which proves that the open source software intermediaries are essential in the software distribution channel.

• The Journal of the Korea Contents Association
• /
• v.16 no.9
• /
• pp.443-450
• /
• 2016

Korean biopharmaceutical industry is a high value-added industries of the country as a key business strategy of the country. The overseas market is accelerating rapidly due to drug demand according to population aging, new drug R&D investment performance visualization, changes in biopharmaceutical R&D center, strategic foreign technology exports, and the active support of government. Therefore, the domestic pharmaceutical companies also should enhance the competitiveness as global pharmaceutical companies and need to build the image of their own company that can be trusted by consumers. This study compared and analyzed visual characteristics shown in the CI symbol mark and age-specific preferences of domestic pharmaceutical companies recognizing the importance of CI as a marketing tool. As a result, preference for the symbol mark had been shown to be significantly higher preference of the old logotype as the age group is higher being proportional to awareness. In addition, the picture-type symbol mark was totally preferred rather than the word mark. Among the picture-type symbol mark, the form of the nature was strongly preferred rather than abstract form. The company also requires a sense of responsibility for recognizing changes in the mass to the globalization. It is hoped that this study will help to develop symbol mark direction as the basis for the identity strategies to improve the image of domestic pharmaceutical companies with global competitiveness.

• International Journal of Highway Engineering
• /
• v.17 no.6
• /
• pp.11-18
• /
• 2015

PURPOSES : The purpose of this thesis is to evaluate the effectiveness of an active noise cancellation (ANC) system in reducing the traffic noise level against frequencies from the predictive model developed by previous research. The predictive model is based on ISO 9613-2 standards using the Noble close proximity (NCPX) method and the pass-by method. This means that the use of these standards is a powerful tool for analyzing the traffic noise level because of the strengths of these methods. Traffic noise analysis was performed based on digital signal processing (DSP) for detecting traffic noise with the pass-by method at the test site. METHODS : There are several analysis methods, which are generally divided into three different types, available to evaluate traffic noise predictive models. The first method uses the classification standard of 12 vehicle types. The second method is based on a standard of four vehicle types. The third method is founded on 5 types of vehicles, which are different from the types used by the second method. This means that the second method not only consolidates 12 vehicle types into only four types, but also that the results of the noise analysis of the total traffic volume are reflected in a comparison analysis of the three types of methods. The constant percent bandwidth (CPB) analysis was used to identify the properties of different frequencies in the frequency analysis. A-weighting was applied to the DSP and to the transformation process from analog to digital signal. The root mean squared error (RMSE) was applied to compare and evaluate the predictive model results of the three analysis methods. RESULTS : The result derived from the third method, based on the classification standard of 5 vehicle types, shows the smallest values of RMSE and max and min error. However, it does not have the reduction properties of a predictive model. To evaluate the predictive model of an ANC system, a reduction analysis of the total sound pressure level (TSPL), dB(A), was conducted. As a result, the analysis based on the third method has the smallest value of RMSE and max error. The effect of traffic noise reduction was the greatest value of the types of analysis in this research. CONCLUSIONS : From the results of the error analysis, the application method for categorizing vehicle types related to the 12-vehicle classification based on previous research is appropriate to the ANC system. However, the performance of a predictive model on an ANC system is up to a value of traffic noise reduction. By the same token, the most appropriate method that influences the maximum reduction effect is found in the third method of traffic analysis. This method has a value of traffic noise reduction of 31.28 dB(A). In conclusion, research for detecting the friction noise between a tire and the road surface for the 12 vehicle types needs to be conducted to authentically demonstrate an ANC system in the Republic of Korea.

• International Journal of Highway Engineering
• /
• v.13 no.4
• /
• pp.29-40
• /
• 2011

Warm-Mix Asphalt(WMA) technologies have been developed since 15 years ago, which are internationally and domestically concerned with energy-saving and environmental-friendly technologies in public and private sectors of highway engineering. The performance of asphalt mass is traditionally evaluated by the penetration, viscosity, or Superpave tests. This research, however, is focused more on the properties depending on asphalt film thicknesses instead of evaluating asphalt mass behaviors by those tests. For this approach, a new testing protocol and analysis method are described by the bonding properties on each film thickness. This testing method and analysis tool are borrowed from those of DSR Moisture Damage test and applied by using ARES. The analysis results indicate that there is a limit film thickness between $200{\mu}m$ and $400{\mu}m$, which causes significant changes of the properties. In addition, the results show that the property changes of Hot-Mix Asphalt(HMA) and WMA on the limit film thickness are also different. Therefore, it is suggested that the properties on thin film thicknesses between $200{\mu}m$ and $400{\mu}m$ should be considered in order to evaluate WMA properly.