• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.5
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• pp.1339-1355
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• 2023

Localization is a hot research spot for many areas, especially in the mobile robot field. Due to the weak signal of the global positioning system (GPS), the alternative schemes in an indoor environment include wireless signal transmitting and receiving solutions, laser rangefinder to build a map followed by a re-localization stage and visual positioning methods, etc. Among all wireless signal positioning techniques, Wi-Fi is the most common one. Wi-Fi access points are installed in most indoor areas of human activities, and smart devices equipped with Wi-Fi modules can be seen everywhere. However, the localization of a mobile robot using a Wi-Fi scheme usually lacks orientation information. Besides, the distance error is large because of indoor signal interference. Another research direction that mainly refers to laser sensors is to actively detect the environment and achieve positioning. An occupancy grid map is built by using the simultaneous localization and mapping (SLAM) method when the mobile robot enters the indoor environment for the first time. When the robot enters the environment again, it can localize itself according to the known map. Nevertheless, this scheme only works effectively based on the prerequisite that those areas have salient geometrical features. If the areas have similar scanning structures, such as a long corridor or similar rooms, the traditional methods always fail. To address the weakness of the above two methods, this work proposes a coarse-to-fine paradigm and an improved localization algorithm that utilizes Wi-Fi to assist the robot localization in a geometrically similar environment. Firstly, a grid map is built by using laser SLAM. Secondly, a fingerprint database is built in the offline phase. Then, the RSSI values are achieved in the localization stage to get a coarse localization. Finally, an improved particle filter method based on the Wi-Fi signal values is proposed to realize a fine localization. Experimental results show that our approach is effective and robust for both global localization and the kidnapped robot problem. The localization success rate reaches 97.33%, while the traditional method always fails.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.24-31
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• 2017

As the concept of sustainability becomes more and more popular, a large amount of literature have been recorded recently on intelligent green building and smart city (IGB&SC). It is therefore needed to systematically analyse the existing knowledge structure as well as the future new development of this domain through the identification of the thematic trends, landmark articles, typical keywords together with co-operative researchers. In this paper, Citespace software package is applied to analyse the citation networks and other relevant data of the past eleven years (from 2006 to 2016) collected from Web of Science (WOS). Through this, a series of professional document analysis are conducted, including the production of core authors, the influence made by the most cited authors, keywords extraction and timezone analysis, hot topics of research, highly cited papers and trends with regard to co-citation analysis, etc. As a result, the development track of the IGB&SC domains is revealed and visualized and the following results reached: (i) in the research area of IGB&SC, the most productive researcher is Winters JV and Caragliu A is most influential on the other hand; (ii) different focuses of IGB&SC research have been emerged continually from 2006 to 2016 e.g. smart growth, sustainability, smart city, big data, etc.; (iii) Hollands's work is identified with the most citations and the emerging trends, as revealed from the bursts analysis in document co-citations, can be concluded as smart growth, the assessment of intelligent green building and smart city.

• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.135-146
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• 2023

An effective educational program warrants the inclusion of an innovative construction which enhances the higher education efficacy in such a way that accelerates the achievement of desired results and reduces the risk of failures. Educational Decision Support System (EDSS) has currently been a hot topic in educational systems, facilitating the pupil result monitoring and evaluation to be performed during their development. Insufficient information systems encounter trouble and hurdles in making the sufficient advantage from EDSS owing to the deficit of accuracy, incorrect analysis study of the characteristic, and inadequate database. DMTs (Data Mining Techniques) provide helpful tools in finding the models or forms of data and are extremely useful in the decision-making process. Several researchers have participated in the research involving distributed data mining with multi-agent technology. The rapid growth of network technology and IT use has led to the widespread use of distributed databases. This article explains the available data mining technology and the distributed data mining system framework. Distributed Data Mining approach is utilized for this work so that a classifier capable of predicting the success of students in the economic domain can be constructed. This research also discusses the Intelligent Knowledge Base Distributed Data Mining framework to assess the performance of the students through a mid-term exam and final-term exam employing Multi-agent system-based educational mining techniques. Using single and ensemble-based classifiers, this study intends to investigate the factors that influence student performance in higher education and construct a classification model that can predict academic achievement. We also discussed the importance of multi-agent systems and comparative machine learning approaches in EDSS development.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.8 s.145
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• pp.1176-1187
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• 2005

The purpose of this study was to evaluate the efficiency of cooling vests developed for farm workers harvesting red pepper in summer. The study was performed using the following two steps: 1) Climatic chamber test, 2) Field test. For the chamber test, a work environment was simulated as $33^{\circ}C$ and $65\%$RH, and the thermo-physiological and subjective responses were measured with and without cooling vests. Twelve young males participated as subjects. For the field test, three farmers participated while harvesting red pepper on the form, in summer. The measurements used were same as in the chamber test. Subjects were tested without any cooling vests, as a control. They were tested wearing vests with 2 frozen gel packs (CV2: Cooling area, $308cm^2$), and vests with 4 frozen gel packs (CV4: Sooting area, $616cm^2$). As a result of the chamber test, rectal temperature($T_{re}$) and mean skin temperature( $T_{sk}$) were lower in both CVs than in Control, and this tendency was statistically significant in CV4 (p<.05). Clothing microclimate temperature ($T_{clo}$) and total sweat rate (TSR) were significantly lower when wearing cooling vests (p<.05) Heart rate (HR) was also lower in wearing cooling vests than in Control, and the speed of recovery to the comfort level was faster when the subjects wore cooling vests. In addition, subjects felt 'less hot, less humid, and less uncomfortable' in both CVs than in Control. Field tests showed a similar tendency with the chamber tests. In particular, wearing the cooling vest was effective in restraining the raise of $T_{clo}$ on the back. It can be concluded that the cooling vest was effective in alleviating heat strain and discomfort in both the chamber test and the field test, despite the cooling area of the cooling vest being just $3.4\%$ of the body surface area ($616cm^2$).

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1320-1325
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• 2012

This study investigated the bulk properties of red pepper powders according to drying method and variety. Bulk density, compressive characteristics, irrecoverable work, dynamic angle, and stress relaxation were investigated. Loose bulk density ranged between 0.420 $g/cm^3$ for Cheongyang cultivar and 0.427 $g/cm^3$ for Hanbando cultivar by hot-air drying. The highest tapped bulk density was 0.586 $g/cm^3$ for Hanbando cultivar by far-infrared drying and the lowest value was 0.523 $g/cm^3$ for Hanbando cultivar by sun drying. Hausner ratio reached a maximum value of 1.370 for Hanbando cultivar by far-infrared drying. Compressibility ranged between 0.0016 for Cheongyang cultivar by sun drying and 0.0023 for Hanbando cultivar by far-infrared drying. Compression ratio reached a maximum value of 1.032 for Hanbando cultivar by hot-air drying. Dynamic angle of repose ranged between 37.47 and $42.97^{\circ}$. Irrecoverable work ranged between 76.0 and 81.7%. Relaxation reached a maximum value of 24.31% for Cheongyang cultivar by far-infrared drying.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.619-624
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• 1999

This work was to study the potential health food use of germinated colored rice after germinating and drying using microwave under vacuum. Colored rice was soaked in water at $15^{\circ}C$ for 2 days and then germinated at $25^{\circ}C$ for $3{\sim}4\;days$. The germinated colored rice was dried by different drying methods: microwave vacuum drying 1, microwave vacuum drying $2\;(drying{\rightarrow}crushing{\rightarrow}drying)$, hot air drying, vacuum drying and freeze drying. Each drier except freeze drier was set to maintain the sample temperature at $60^{\circ}C$. During microwave vacuum drying 1 or 2, the sample reached $60^{\circ}C$ much faster (within 5 min) and was dried much faster ($2{\sim}3\;hrs$ than the other drying methods. The initial drying rate of microwave vacuum drying was ten times faster than that of hot air drying. The microwave vacuum drying 2 retained the highest ${\alpha}-amylase$ activity, followed by microwave vacuum drying 1, freeze drying, vacuum drying, and hot air drying.

• Journal of Korean Public Health Nursing
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• v.9 no.1
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• pp.83-102
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• 1995

As the society is being industrialized, the fast-paced economic development that has caused substantial increase in cerebrovascular and coronary artery diseases and the industrial development and increased use of means of transportation have resulted in the rapid rise of incidents in external injuries as well. So the pubic has become acutely aware of the need for fast and effective emergency care delivery system. The goal of emergency care delivery system is to meet the emergency care needs of patients. The emergency care delivery system is seeking to efficiently satisfy the care needs of people. Therefore the purpose of this study is designed to develop an effective programs for emergency care delivery system in Korea. The following specific objectives were investigated. This emergency care delivery system must have the necessary man power, for transfering the patients, communication net work, and emergency care facilities. 1) Man power Emergency care requires n0t only specialized traning in the emergency treatment but also knowledge and experience i11 other related area, so emergency care personnel traning program should be designed in order to adapt to the specific need of emergency patients. It will be necessary to ensure professional personnel who aquires the sufficient traning and experience for emergency care and to look for legal basis. We have to develop re-educational programs for emergency nurse specialist. They should be received speciality of emergency nursing care so that they will work actively and positively in emergency part. Emergency medical doctor and nurse specialist should be given an education which is related in emergency and critical care. Emergency care personnel will continue to provide both acute and continuing care as partner with other medical team. 2) Transfering the patients. Successful management of pre-hospital care requires adequate traning for the emergency medical technician. Traning program should be required to participate in a actual first aids activites in order to have apportunities to acquire practical skills as well as theoretical knowledge. The system of emergency medical technician should be remarkablly successful with first responder firefighters. Establishing this system must add necessary ambulances operating at any given time. It will be necessary to standardize the ambulance size and equipment. Ambulance should be arranged with each and every fire station. 3) Communication net work. The head office of emergency commumication network should be arranged with the head office of fire station in community. It is proposed that Hot-line system for emergency care should be introduce. High controlled ambulance and thirtial emergency center should simultaneously equip critical-line in order to communication with each other. Ordinary ambulance and secondary emergency facility should also simultaneously equip emergency-line in order to communication with each other. 4) Emergency care facilities. Primary emergency care facilities should be covered with the ambulatory emergency patients-minor illness and injuires. Secondary emergency care facilities should be covered with the emergency admission patients. Third emergency care center should be covered with the critical patients who need special treatments and operation. Secondary and third emergency care facilities should employ emergency medical doctor and emergency nurse specialist to treat in-patients with severe and acute illness and multiple injuires. It should be fashioned for a system of emergency facilities that meets emergency patients needs. Provide incentives for increased number of emergency care facilities with traning in personal/clinical emergency care. 5) Finance It is recommended to put the finance of a emergency care on a firm basis. The emergency care delivery system should be managed by the government or accreditted organizations. In order to facilitate this relevant program the fund is needed for more efficient and effective emergency researchs, service, programs, and policy. 6) Gaining understanding and co-operation of pubic It is also important to undertake pubic education to improve understanding of first aids and C. P. R of individuals, communities and business. It is proposed that teachers and health officers be certified in C. P. R. The C. P. R education can be powerful influence save lives. Lastly appropriate emergency care information must be provided to the pubic for assisting them in choosing emergency care.

• Journal of Intelligence and Information Systems
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• v.27 no.3
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• pp.95-112
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• 2021

In university education, the choice of major class plays an important role in students' careers. However, in line with the changes in the industry, the fields of major subjects by department are diversifying and increasing in number in university education. As a result, students have difficulty to choose and take classes according to their career paths. In general, students choose classes based on experiences such as choices of peers or advice from seniors. This has the advantage of being able to take into account the general situation, but it does not reflect individual tendencies and considerations of existing courses, and has a problem that leads to information inequality that is shared only among specific students. In addition, as non-face-to-face classes have recently been conducted and exchanges between students have decreased, even experience-based decisions have not been made as well. Therefore, this study proposes a recommendation system model that can recommend college major classes suitable for individual characteristics based on data rather than experience. The recommendation system recommends information and content (music, movies, books, images, etc.) that a specific user may be interested in. It is already widely used in services where it is important to consider individual tendencies such as YouTube and Facebook, and you can experience it familiarly in providing personalized services in content services such as over-the-top media services (OTT). Classes are also a kind of content consumption in terms of selecting classes suitable for individuals from a set content list. However, unlike other content consumption, it is characterized by a large influence of selection results. For example, in the case of music and movies, it is usually consumed once and the time required to consume content is short. Therefore, the importance of each item is relatively low, and there is no deep concern in selecting. Major classes usually have a long consumption time because they have to be taken for one semester, and each item has a high importance and requires greater caution in choice because it affects many things such as career and graduation requirements depending on the composition of the selected classes. Depending on the unique characteristics of these major classes, the recommendation system in the education field supports decision-making that reflects individual characteristics that are meaningful and cannot be reflected in experience-based decision-making, even though it has a relatively small number of item ranges. This study aims to realize personalized education and enhance students' educational satisfaction by presenting a recommendation model for university major class. In the model study, class history data of undergraduate students at University from 2015 to 2017 were used, and students and their major names were used as metadata. The class history data is implicit feedback data that only indicates whether content is consumed, not reflecting preferences for classes. Therefore, when we derive embedding vectors that characterize students and classes, their expressive power is low. With these issues in mind, this study proposes a Net-NeuMF model that generates vectors of students, classes through network analysis and utilizes them as input values of the model. The model was based on the structure of NeuMF using one-hot vectors, a representative model using data with implicit feedback. The input vectors of the model are generated to represent the characteristic of students and classes through network analysis. To generate a vector representing a student, each student is set to a node and the edge is designed to connect with a weight if the two students take the same class. Similarly, to generate a vector representing the class, each class was set as a node, and the edge connected if any students had taken the classes in common. Thus, we utilize Node2Vec, a representation learning methodology that quantifies the characteristics of each node. For the evaluation of the model, we used four indicators that are mainly utilized by recommendation systems, and experiments were conducted on three different dimensions to analyze the impact of embedding dimensions on the model. The results show better performance on evaluation metrics regardless of dimension than when using one-hot vectors in existing NeuMF structures. Thus, this work contributes to a network of students (users) and classes (items) to increase expressiveness over existing one-hot embeddings, to match the characteristics of each structure that constitutes the model, and to show better performance on various kinds of evaluation metrics compared to existing methodologies.

• Journal of KIISE:Information Networking
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• v.35 no.2
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• pp.99-111
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• 2008

In recent years, the needs for WLANs(Wireless Local Area Networks) technology which can access to Internet anywhere have been dramatically increased particularly in SOHO(Small Office Home Office) and Hot Spot. However, unlike wired networks, there are some unique characteristics of wireless networks. These characteristics include the burst packet losses due to unreliable wireless channel. Note that burst packet losses, which occur when the distance between the wireless station and the AP(Access Point) increase or when obstacles move temporarily between the station and AP, are very frequent in 802.11 networks. Conversely, due to burst packet losses, the performance of 802.11 networks are not always as sufficient as the current application require, particularly when they use TCP at the transport layer. The high packet loss rate over wireless links can trigger unnecessary execution of TCP congestion control algorithm, resulting in performance degradation. In order to overcome the limitations of WLANs environment, MAC-layer LDA(Loss Differentiation Algorithm)has been proposed. MAC-layer LDA prevents TCP's timeout by increasing CRD(Consecutive Retry Duration) higher than burst packet loss duration. However, in the wireless channel with high packet loss rate, MAC-layer LDA does not work well because of two reason: (a) If the CRD is lower than burst packet loss duration due to the limited increase of retry limit, end-to-end performance is degraded. (b) energy of mobile device and bandwidth utilization in the wireless link are wasted unnecessarily by Reducing the drainage speed of the network buffer due to the increase of CRD. In this paper, we propose a new retransmission module based on Cross-layer approach, called BLD(Burst Loss Detection) module, to solve the limitation of previous link layer retransmission schemes. BLD module's algorithm is retransmission mechanism at IEEE 802.11 networks and performs retransmission based on the interaction between retransmission mechanisms of the MAC layer and TCP. From the simulation by using ns-2(Network Simulator), we could see more improved TCP throughput and energy efficiency with the proposed scheme than previous mechanisms.

• Journal of the Korean association of regional geographers
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• v.11 no.5
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• pp.488-499
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• 2005

The trends of Chinese and Yanbian University's reform were studied in this work. Although the history of Chinese modem university education is short, and all Chinese Universities experienced same social problems, however, development of each university was different. Especially after 90's, with applying socialism market economy theory, Chinese university education have changed a lot. Main conclusions were summarized as follows. First, to exert university's self-determination, University management system was changed. More and more rights and freedoms of operating university were given to universities which were originally controlled by central and local government. With that, universities were cheered to develop extensively based on its ability. Second, efforts to fit market economy were observed. It reflects in all aspects, such as systems of university financing, operating, admission and graduation of students. Third, professor competition system was adopted to promote professors enthusiasm. Forth, to survival in hot competition among universities, differentiation policy was applied. In brief, it could be said that rapid developments of Chinese university education have achieved recently. However, problems such as universities are still under supervision of central and local government: expand of university scale rather than education quality was focused on: limit of investment to university: lack of legal protection for finical supporting: lack of university democratization were still remain. It was expected that these problems will be solved in future university reforms.