• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.141-156
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• 2013

Social media is a representative form of the Web 2.0 that shapes the change of a user's information behavior by allowing users to produce their own contents without any expert skills. In particular, as a new communication medium, it has a profound impact on the social change by enabling users to communicate with the masses and acquaintances their opinions and thoughts. Social media data plays a significant role in an emerging Big Data arena. A variety of research areas such as social network analysis, opinion mining, and so on, therefore, have paid attention to discover meaningful information from vast amounts of data buried in social media. Social media has recently become main foci to the field of Information Retrieval and Text Mining because not only it produces massive unstructured textual data in real-time but also it serves as an influential channel for opinion leading. But most of the previous studies have adopted broad-brush and limited approaches. These approaches have made it difficult to find and analyze new information. To overcome these limitations, we developed a real-time Twitter trend mining system to capture the trend in real-time processing big stream datasets of Twitter. The system offers the functions of term co-occurrence retrieval, visualization of Twitter users by query, similarity calculation between two users, topic modeling to keep track of changes of topical trend, and mention-based user network analysis. In addition, we conducted a case study on the 2012 Korean presidential election. We collected 1,737,969 tweets which contain candidates' name and election on Twitter in Korea (http://www.twitter.com/) for one month in 2012 (October 1 to October 31). The case study shows that the system provides useful information and detects the trend of society effectively. The system also retrieves the list of terms co-occurred by given query terms. We compare the results of term co-occurrence retrieval by giving influential candidates' name, 'Geun Hae Park', 'Jae In Moon', and 'Chul Su Ahn' as query terms. General terms which are related to presidential election such as 'Presidential Election', 'Proclamation in Support', Public opinion poll' appear frequently. Also the results show specific terms that differentiate each candidate's feature such as 'Park Jung Hee' and 'Yuk Young Su' from the query 'Guen Hae Park', 'a single candidacy agreement' and 'Time of voting extension' from the query 'Jae In Moon' and 'a single candidacy agreement' and 'down contract' from the query 'Chul Su Ahn'. Our system not only extracts 10 topics along with related terms but also shows topics' dynamic changes over time by employing the multinomial Latent Dirichlet Allocation technique. Each topic can show one of two types of patterns-Rising tendency and Falling tendencydepending on the change of the probability distribution. To determine the relationship between topic trends in Twitter and social issues in the real world, we compare topic trends with related news articles. We are able to identify that Twitter can track the issue faster than the other media, newspapers. The user network in Twitter is different from those of other social media because of distinctive characteristics of making relationships in Twitter. Twitter users can make their relationships by exchanging mentions. We visualize and analyze mention based networks of 136,754 users. We put three candidates' name as query terms-Geun Hae Park', 'Jae In Moon', and 'Chul Su Ahn'. The results show that Twitter users mention all candidates' name regardless of their political tendencies. This case study discloses that Twitter could be an effective tool to detect and predict dynamic changes of social issues, and mention-based user networks could show different aspects of user behavior as a unique network that is uniquely found in Twitter.

• Korean journal of food and cookery science
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• v.25 no.4
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• pp.488-495
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• 2009

Pork cutlet is a favorite deep fat fried food item among Korean children, and an excellent protein-containing food, and as well as a simple and economical cuisine. However, the frying process adds a significant amount of calories. We added MC (Methylcellulose) and HPMC (Hydroxypropyl Methylcellulose) to the batter in an effort to reduce oil uptake in prepared pork cutlets. After additions of MC and HPMC at concentrations of 0.5, 1, and 1.5% respectively, we assessed the viscosity of batter, color after frying, the increases in moisture retention and oil uptake, and sensory characteristics, comparing each quality. The viscosity of batter with 0.5% HPMC added (w/w) was similar to that of the controls, but the viscosity of all the batter with added MC was so much higher that it was difficult to use the batter for coating at the same temperature, leading to a failure even to prepare a sample. After frying, the batter with added HPMC provided significantly less oil uptake and more moisture retention than the batter to which MC was added. Additionally, with regard to color and sensory characteristics, the pork cutlet with 0.5% added HPMC was superior to the other samples. According to these results, we concluded that when cellulose derivatives are added in order to reduce oil uptake and to raise the moisture retention of the batter of pork cutlet, HPMC is more useful in this regard than MC. Additionally, the batter with 0.5% HPMC added appears to be the best of the tested choices, for three reasons: first, the viscosity of the batter is similar to that of the controls; second, the taste is not greasy after frying as the result of the reduced oil uptake and higher moisture retention; and third, the sensory characteristics of this sample, such as, color, crispiness, and hardness were the best among samples.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.6
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• pp.327-340
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• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.561-578
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• 1999

The goal of periodontal therapy is the periodontal regeneration by the removal of microorganisms and their toxic products from the periodontally diseased root surface. To achieve periodontal regeneration, root conditioning as an adjunct to root planing has been done. There are low pH etchants such as citric acid, tetracycline-HCl, and EDTA solution which is a neutral chelating agent. The purpose of present study was to examine the effect of root conditioning by citric acid, tetracycline HCl, and EDTA. Total 35 root specimens(6${\times}$3${\times}$2mm) were prepared from the periodontally diseased teeth, scaled and root planed. The specimens were treated with normal saline for 1 minute, saturated citric acid(pH 1) for 3 minutes, 50mg/ml tetracycline-HCl(pH 2) for 5 minutes, 15% EDTA(pH 7) for 5 minutes using rubbing technique. The specimens were examined under scanning electron microscopy at 1000, and 3000 magnification. On the microphotographs taken at 1000 magnification, the numbers of opened and patent dentinal tubules per unit area(10,640${\mu}m^2$) were counted. And the diameters of opened dentinal tubules per unit are (10,640${\mu}m^2$) were measured. The differences of number and diameter among all groups were statistically analyzed by Kruskal Wallis Test. The results were as follows; 1. In the specimens applied with normal saline(control group), the root surface was finely cracked, and was covered by irregular smear layer. Neither exposed dentinal tubules nor any patent dentinal tubules could be seen. 2. In the specimens applied with saturated citric acid(experimental 1 group), the globular collagen fibers were exposed around the peritubular space, and many dentinal tubules were revealed. 3. In the specimens applied with tetracycline-HCl(experimental 2 group), the process-like collagen fibers were exposed around the peritubular space, and some dentinal tubules were revealed. 4. In the specimens applied with 15% EDTA(experimental 3 group), the root surface was covered by the collagenous fibrillar network, and many dentinal tubules were revealed. 5. The numbers of opened and patent dentinal tubules were significantly more in exp. 1 group and exp. 3 group than in exp. 2 group(P<0.05). But there was no significant difference between exp. 1 group and exp. 3 group. In control group, the number of opened and patent dentinal tubules could not be counted because any dentinal tubules couldn't be seen. 6 . The diameter of opened dentinal tubules was significantly smaller in exp. 1 group and exp. 3 group than in exp. 2 group(P<0.05). But there was no significant difference between exp. 1 group and exp. 3 group. In control group, the diameter of opened dentinal tubules could not be measured because any dentinal tubules couldn't be seen. The results demonstrate that root conditioning with citric acid, tetracycline- HCl, and EDTA is more effective in periodontal healing than only root planing, and 15% EDTA solution can replace low pH etching agents such as citric acid, tetracycline-HCl for root conditioning.

• Korean Security Journal
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• no.36
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• pp.111-137
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• 2013

The purpose of this study is to examine the effects of electronic security service quality satisfaction and customer satisfaction on switching barrier and customer loyalty. Survey questionnaires were distributed to business owners in Seoul that are using electronic security system and the total of 500 copies were used as research data except 60 copies with insufficient responses. The results are as follow. First, as for the effects of electronic security service quality satisfaction on electronic security customer satisfaction, it indicates that the higher electronic security service quality satisfaction achieves, the more it has positive effects on electronic security customer satisfaction. Second, as for the effects of electronic security service quality satisfaction on switching cost, it indicates that the higher electronic security service quality satisfaction achieves, the more it has positive effects on switching cost. As for the effects of electronic security service quality satisfaction on human relations, it indicates that the higher electronic security service quality satisfaction achieves, the more it has positive effects on human relations. It indicates that the effects of electronic security service quality satisfaction on alternative attraction was not meaningful. Third, as for the effects of electronic security customer satisfaction on switching cost, it indicates that the higher electronic security customer satisfaction achieves, the more it has positive effects on switching cost. As for the effects of electronic security customer satisfaction on human relations, it indicates that the higher electronic security customer satisfaction achieves, the more it has positive effects on human relations. But, it indicates that the effects of electronic security customer satisfaction on alternative attraction was not meaningful. Fourth, As for the effects of electronic security service quality satisfaction and electronic security customer satisfaction on customer loyalty, it indicates that the higher electronic security service quality satisfaction achieves, the more it has positive effects on customer loyalty. As for the effects of switching cost on customer loyalty, it indicates that the higher switching cost achieves, the more it has positive effects on customer loyalty. As for the effects of alternative attraction on customer loyalty, it indicates that there is no meaningful relation between alternative attraction and customer loyalty. But, effects of human relations on customer loyalty, it indicates that there is no meaningful relation between human relations and customer loyalty. Based on the above results, it is noticeable that in the effects of electronic security service quality satisfaction and electronic security customer satisfaction on switching barrier, all of them had meaningful effects except for alternative attractiveness. This signifies that switching barrier factor can increase when the service quality of electronic security and customer satisfaction increase. In other words, it can be said that increased awareness of electronic security service quality satisfaction and electronic security customer satisfaction by electronic security users can lead to high customer loyalty by establishing switching barrier through such increased awareness.

• Journal of Christian Education in Korea
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• v.63
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• pp.91-120
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• 2020

This study suggests a spiritual education for the Christian family as a strategy to cope with the risky situation of the Korean Church during the Covid-19 pandemic. Today, we live in a chaotic epoch since the rapid development of the science caused the Fourth Industrial Revolution and the Covid-19 pandemic gave rise to a wide array of changes throughout the society. Korean Church in these circumstances is required to have relevant responses to the kaleidoscopic changes. Especially, not to mention the face-to-face public worship service, in the situation where the congregation members even find it difficult to meet one another in a small group, it becomes a crucial issue how Christians maintain their faith and community in the healthy spirituality. As such, viewing that Christian education within the family will become much more important, this study conducts research for familial-spiritual education. For the research, this paper, first of all, attempts to understand the era of Covid-19. It is to see what the Novel Corona Virus is and what the feature of the epoch of Covid-19 might be. Based upon the understanding, this research discusses what Christian spirituality is asked for and the orientation towards which Christian education should go on. It is particularly to say that a spiritual education for the family becomes integral. The education for the family might be possible through Bibliodrama so that this study establishes a specific model of Christian education employing Bibliodrama. The discussion above shows three academic significances. First, this paper, within the domain of Christian education, suggests an alternative research which is to solve Korean Church's diverse problems caused by Covid-19. Second, this research attempts an analytical understanding of the Covid-19 period within the Christian education area. Finally, when specific and practical research for the field of Christian education during the Covid-19 pandemic is required, this study considers that Christian education within the family is overarching, thus proposing a specific model for familial-spiritual education hiring Bibliodrama.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.3
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• pp.223-230
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• 2002

Investigations were made on catch composition, sex ratio, relationships between carapace length, body weight and fecundity and spawning season of major target shrimps (Acetes chinensis, A. japonicus) in the shrimp fishing areas of south-western coastal waters, accounting for about $45\%$ of annual shrimp landings in Korea. Catches were collected monthly in the fishing areas from March 2000 to February 2001, using single pocket-walled fishing gear, Total 59 species (shrimps 14, fishes 34, other crustaceans 8 and cephalopods 3 species) occurred. During the study period the bycatch-to-shrimp ratio of shrimp fishery was 2.42 in April 2000 and less than 1 for all months except for August 2000 and Febuary 2001. Compared with shrimp fishery of other areas and nations, these results indicate that effect of the fishing gear on catches of other species is minor, suggesting higher gear selectivity for shrimps. Of shrimps, there were two dominant species (A. chinensis, A. japonirus). Average sex ratio was 1.44 $\pm$ 0.42 for A. japonicus and 1,44 $\pm$ 0.43 for A. chinensis, which are dominant females in August. Average fecundity was 4,812 $\pm$ 1,511 for A. japonicus and 5,561 $\pm$ 1,900 for A. chinensis. In the two species mature females were found in the period from May to August. Similarly, the gonadosomatic index (GSI) was higher in July and August, with a peak in July, These results indicate that their main spawning season was summer.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.95-108
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• 2011

TThis is a study of the personalization method that intelligently adapts the level of clustering considering purchasing index of a customer. In the e-biz era, many companies gather customers' demographic and transactional information such as age, gender, purchasing date and product category. They use this information to predict customer's preferences or purchasing patterns so that they can provide more customized services to their customers. The previous Customer-Segmentation method provides customized services for each customer group. This method clusters a whole customer set into different groups based on their similarity and builds predictive models for the resulting groups. Thus, it can manage the number of predictive models and also provide more data for the customers who do not have enough data to build a good predictive model by using the data of other similar customers. However, this method often fails to provide highly personalized services to each customer, which is especially important to VIP customers. Furthermore, it clusters the customers who already have a considerable amount of data as well as the customers who only have small amount of data, which causes to increase computational cost unnecessarily without significant performance improvement. The other conventional method called 1-to-1 method provides more customized services than the Customer-Segmentation method for each individual customer since the predictive model are built using only the data for the individual customer. This method not only provides highly personalized services but also builds a relatively simple and less costly model that satisfies with each customer. However, the 1-to-1 method has a limitation that it does not produce a good predictive model when a customer has only a few numbers of data. In other words, if a customer has insufficient number of transactional data then the performance rate of this method deteriorate. In order to overcome the limitations of these two conventional methods, we suggested the new method called Intelligent Customer Segmentation method that provides adaptive personalized services according to the customer's purchasing index. The suggested method clusters customers according to their purchasing index, so that the prediction for the less purchasing customers are based on the data in more intensively clustered groups, and for the VIP customers, who already have a considerable amount of data, clustered to a much lesser extent or not clustered at all. The main idea of this method is that applying clustering technique when the number of transactional data of the target customer is less than the predefined criterion data size. In order to find this criterion number, we suggest the algorithm called sliding window correlation analysis in this study. The algorithm purposes to find the transactional data size that the performance of the 1-to-1 method is radically decreased due to the data sparity. After finding this criterion data size, we apply the conventional 1-to-1 method for the customers who have more data than the criterion and apply clustering technique who have less than this amount until they can use at least the predefined criterion amount of data for model building processes. We apply the two conventional methods and the newly suggested method to Neilsen's beverage purchasing data to predict the purchasing amounts of the customers and the purchasing categories. We use two data mining techniques (Support Vector Machine and Linear Regression) and two types of performance measures (MAE and RMSE) in order to predict two dependent variables as aforementioned. The results show that the suggested Intelligent Customer Segmentation method can outperform the conventional 1-to-1 method in many cases and produces the same level of performances compare with the Customer-Segmentation method spending much less computational cost.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.194-200
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• 2017

This study aimed to determine the suitable of harvest time on the growth and quality of baby leafy vegetables (Agastsche rugosa O. Kuntze and Lepidium sativum L.) grown on rice seedling tray in a six-layered bench system at 30cm intervals in order to exploit the space during rice growing off-season. Seedlings were grown on the rice seedling tray for 10 days after sowing with coir substrate supplied with nutrient solution at EC $1.5dS{\cdot}m^{-1}$ every 2 days prior to placing the tray on the bench, which were at $1^{st}$ (Low) layer above 20cm and $6^{th}$ (High) layer above 170cm apart from the ground. Growth and phytochemical contents were measured at 7-day and 14-day harvest time. During the culture periods, daily average of integrated solar radiation and temperature were $9.3{\sim}9.6MJ{\cdot}m^{-2}$, $27.5^{\circ}C$ in the High layer and $5.1{\sim}6.2MJ{\cdot}m^{-2}$ in average, and $26.5{\sim}26.6^{\circ}C$ in the Low layer, respectively. For A. rugosa, the highest growth was observed in the Low layer bench at a 14-day harvest time, while their plant height in the High layer was shorter and the leaf number was lower. For L. sativum, the plant height, leaf length and width, leaf number and fresh weight were higher in the Low layer. For A. rugosa, a high yield was observed with the increase in integrated temperature and integrated solar radiation, while a higher yield of L. sativum was found with the increase in integrated temperature, but not with integrated solar radiation. For A. rugosa, both polyphenol and anthocyanin contents were higher in the High layer at a 14-day harvest time. For L. sativum, polyphenol contents were higher in the High layer, whereas no significant difference in anthocyanin and flavonoid contents was observed depending on the layer and harvest time. The highest chlorophyll content showed in Low layer at a 7-day harvest time in both A. rugose and L. sativum. All of the results suggest that in terms of growth and quality, it may be better growing in the high layer for 14 days after seedling in A. rugosa, and low layer for 7 days in L. sativum.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.59-66
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• 2002

This study was proposed as an exploratory study for understanding the biological bases and structures of three personality models: Eysenck's PEN model, Gray's BIS/BAS model, and Costa & McCrae's Five Factor Model, which was chosen as the major descriptive model regardless of its biological bases. Besides, Eysenck's impulsivity scale, IVE, was added to demonstrate the relationship of P and impulsivity. Concerning personality, most previous reports have explored the relationships between P300 and the introversion-extraversion of Eysenck's theory because of its putative biological bases. In the present study, forty-eight undergraduate took four personality batteries (ERQ-R, NEO-Pl-R, BIS/BAS, and IVE). Two types of oddball tasks including different stimulus duration were used to induce ERPs (50ms for task 1, 300ms for task 2). Distributional topographies of correlation coefficients with personality traits and ERP components were drawn, and considered for the consistent interpretation of the personality model structures. Even though all equivalences for extraversion of personality batteries showed similarities for their intra-correlation, their correlations with P3 amplitudes were dissociate. Eysenck's E might not be the proper psychometric measure for elucidating its biological bases. The present study supported the negative relationship of P3 amplitude and extraversion, which is the consensus of previous studies. Neuroticism and Psychoticism showed correlations with the earlier sensory processing components such as N1 and P2. This result might explain the reason why most of studies have failed to find biological connections relating them. Interaction between gender and personality traits should be considered for the interpretation of correlations. Two types of auditory stimulus duration had different sensitivity to personality traits.