• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.481-491
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• 2015

Since the crack in the surface of the concrete acts as the main reason influencing the life span of the structure, regular inspections and maintenance are required. The sealing required for maintenance of the concrete surface is a method of repairing the crack in the surface in the beginning, and is effective in preventing additional cracks and expansion that occurs with time. However, sealing on large sized structures such as tall buildings or bottom parts of bridges are difficult to ensure safety of the workers due to inadequate working environments. Due to this reason, the importance of the need for sealing automation for the maintenance of large sized concrete structures is emerging. This study proposes two control methods to apply robot systems to the sealing of cracks on the bottom parts of concrete bridges. First is the method of automatically tracking the trajectory of cracks. The robot gets the trajectory of the cracks using video information obtained from cameras. Comparing the previous several points and new point, the next point can be estimated. Thus, the trajectory of the crack can be tracked automatically. The other method is sealing by maintaining steady force to the contacting surface. The concrete surface exposed to an external environment for a long time gets an irregular roughness. If robots are able to carry out sealing while maintaining a steady contact force on these rough surfaces, complete equal sealing can be maintained. In order to maintain this equal force, a force control method using impedance is proposed. This paper introduces two developed control methods to apply to sealing robots, and conducts a Lab Test and Field Test after applying to a robot. Based on the test results, opinions on the possibilities of field application of the robot applied with the control methods are presented.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.760-764
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• 2015

Wireless sensors, installed on machinery, and Time Division Multiple Access (TDMA) transmission make an ideal system for monitoring machine conditions in industrial plants because there is no need for electronic wiring. However, there has not yet been a successful field application of such a system, capable of continuously transmitting data at sample rates greater than 100 Hz. In this research, a TDMA network protocol capable of acquiring data from multiple sensors at sample rates greater than 100 Hz was developed for field application. The protocol was implemented in a single cluster-star topology network, and the system was evaluated based on the node number and transmission distance. Network simulator 2 (ns-2) was used for a real field simulation. Non-TDMA and TDMA protocol cases were compared using four sensor nodes. In the cases of 20-s and 40-s transmission times, there was little difference between the reception rates of the non-TDMA and TDMA systems. However, the difference was much greater when using a 60-s transmission time.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3243-3254
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• 2013

It is well known that increased incidences of lung, skin, and bladder cancers are associated with occupational exposure to PAHs. Animal studies show that certain PAHs also can affect the hematopoietic and immune systems and can produce reproductive, neurologic, and developmental effects. As a consequence, several studies have been attempted to investigate the fate of PAHs in atmospheric environment during the past decades. However, there is still a lack of information in regard to the atmospheric concentration of PAHs during the "Bon Fire Night". In this study, twenty-three polycyclic aromatic hydrocarbons and twenty-eight aliphatics were identified and quantified in the $PM_{10}$ and vapour range in Birmingham ($27^{th}$ November 2001-$19^{th}$ January 2004). The measured concentrations of total particulate and vapour (P+V) PAHs were consistently higher at the BROS in both winter and summer. Arithmetic mean total (P+V) PAH concentrations were $51.04{\pm}47.62$ ng $m^{-3}$ and $22.30{\pm}19.18$ ng $m^{-3}$ at the Bristol Road Observatory Site (BROS) and Elms Road Observatory Site (EROS) respectively. In addition arithmetic mean total (P+V) B[a]P concentrations at the BROS were $0.47{\pm}0.39$ ng $m^{-3}$ which exceeded the EPAQS air quality standard of 0.25 ng $m^{-3}$. On the other hand, the arithmetic mean total (P+V) aliphatics were $81.80{\pm}69.58$ ng $m^{-3}$ and $48.00{\pm}35.38$ ng $m^{-3}$ at the BROS and EROS in that order. The lowest average of CPI and $C_{max}$ measured at the BROS supports the idea of traffic emissions being a principle source of SVOCs in an urban atmosphere. The annual trend of PAHs was investigated by using an independent t-test and oneway independent ANOVA analysis. Generally, there is no evidence of a significant decline of heavier MW PAHs from the two data sets, with only Ac, Fl, Ph, An, 2-MePh, 1+9-MePh, Fluo and B[b+j+k]F showing a statistically significant decline (p<0.05). A further attempt for statistical analysis had been conducted by dividing the data set into three groups (i.e. 2000, 2001-2002 and 2003-2004). For lighter MW compounds a significant level of decline was observed by using one-way independent ANOVA analysis. Since the annual mean of $O_3$ measured in Birmingham City Centre from 2001 to 2004 increased significantly (p<0.05), it may be possible to attribute the annul reduction of more volatile PAHs to the enhanced level of annual average $O_3$. By contrast, the heavier MW PAHs measured at the BROS did not show any significant annual reduction, implying the difficulties of 5- and 6-ring PAHs to be subject to photochemical decomposition. The deviation of SVOCs profile measured at the EROS was visually confirmed during the "Bonfire Night" festival closest to the $6^{th}$ November 2003. In this study, the atmospheric PAH concentrations were generally elevated on this day with concentrations of Fl, Ac, B[a]A, B[b+j+k]F, Ind and B[g,h,i]P being particularly high.

• Journal of KIISE:Databases
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• v.35 no.5
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• pp.421-431
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• 2008

Recently XML is becoming a de facto standard for online data exchange between heterogeneous systems and also the research of streaming XML data filtering comes into the spotlight. Since streaming XML data filtering technique needs rapid matching of queries with XML data, it is required that the query processing should be efficiently performed. Until now, most of researches focused only on partial sharing of path expressions or efficient predicate processing and they were work for time and space efficiency. However, if containment relationship between queries is previously calculated and the lowest level query is matched with XML data, we can easily get a result that high level queries can match with the XML data without any other processing. That is, using this containment technique can be another optimal solution for streaming XML data filtering. In this paper, we suggest an efficient XML data filtering based on prime number indexing and containment relationship between queries. Through some experimental results, we present that our suggested method has a better performance than the existing method. All experiments have shown that our method has a more than two times better performance even though each experiment has its own distinct test purpose.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.88-96
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• 2017

The construction standards in Korea consist of design standards and specifications. They are provided by the national transportation electronic information center in file format, not in a DB, which may lead to their incomplete utilization and versatility, such as a lack of history management and reference functions. This also makes it difficult to cross-refer to standards and manage revision history. In this study, we developed a code management system for the national construction standards by analyzing domestic and overseas related systems, in order to pinpoint the problems in the current system and its development direction and, thus, to suggest a detailed plan for the design and implementation of a code management system. The developed system comprises four subsystems, namely a construction standards making system, construction standards service system, construction standards maintenance system and construction standards portal system. The results of this study are expected to improve the user's convenience by facilitating the revision, operation and history management of the complex and various construction standards, and to provide high-quality national construction standards by effectively supporting the revision and operation of the national construction standards with minimum duplication and conflicts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.418-429
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• 2012

In this study we surveyed the packaging preferences of consumers for Korean rice cakes as current commercial products in Korea. The questionnaire was developed from a preliminary investigation of typical rice cake packaging patterns and sent to 2332 residents in Korea by random sampling mail. The questionnaire contained questions on the preferences of interior design in packaging, opening methods, individually separated types, printing position, packaging methods, and packaging materials such as paper and plastic. There were responses from 304 residents. The collected data was analyzed by an SPSS package program. Most of the packaging used for Korean rice cakes was plastic (58.9%) which was used for packaging materials and stretch wrap (42.9%) as packing methods. The results showed the preference was the perforated line type used by hand for opening a packaging and interior packaging design with 2~3 partitions. Most respondents expressed an interest in using individual packaging and having printing directly on the packaging. Also, the respondents preferred the packaging design that let them see the contents of a package. Based on the results of the questionnaire, this paper suggested that most consumers would prefer to choose a packaging system with a partition design in a plastic container, individually separated products, and a transparent container for Korean rice cakes. The results of packaging preferences could provide important information for suitable packaging development for Korean rice cakes. Further research should be conducted to improve the shelf life of Korean rice cakes with functional packaging systems such as modified atmosphere packaging or anti-microbial packaging.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.7
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• pp.413-420
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• 2006

The speed of present-day network technology exceeds a gigabit and is developing rapidly. When using TCP/IP in these high-speed networks, a high load is incurred in processing TCP/IP protocol in a host CPU. To solve this problem, research has been carried out into TCP/IP Offload Engine (TOE). The TOE processes TCP/IP on a network adapter instead of using a host CPU; this reduces the processing burden on the host CPU. In this paper, we developed two software-based TOEs. One is the TOE implementation using an embedded Linux. The other is the TOE implementation using Lightweight TCP/IP (lwIP). The TOE using an embedded Linux did not have the bandwidth more than 62Mbps. To overcome the poor performance of the TOE using an embedded Linux, we ported the lwIP to the embedded system and enhanced the lwIP for the high performance. We eliminated the memory copy overhead of the lwIP. We added a delayed ACK and a TCP Segmentation Offload (TSO) features to the lwIP and modified the default parameters of the lwIP for large data transfer. With the aid of these modifications, the TOE using the modified lwIP shows a bandwidth of 194 Mbps.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.113-126
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• 2016

The main purpose of this study is to provide the necessary information for educational intervention by discovering the components and factors related to the adaptation experience of male students in the department of nursing. The participants were seven male nursing students. Data were collected from in-depth interviews, and the results were analyzed by the Giorgi's phenomenological analysis method. The main components of adaptation experience of participants were summarized into four categories: 'hopes and expectations for the future careers,' 'conflicts and wandering under realistic issues,' 'compromise and emotion management,' and 'efforts for self-growth.' Causative, accelerative, and recursive characteristics were shown among these components. The adaptation process was structured in the temporal context. The results suggest that for amicable adaptation, internal controls, such as 'improving willpower,' 'inspiring solid career awareness,' and 'selecting adaptation strategy' were all critical. Moreover, the support of families, relatives, college seniors, and department professors were revealed as the factors that help in the adaptation experiences. Based on the results, further studies are required to identify the dropout rates by maladaptation of male nursing students, and analyze possible factors that contribute to dropout and maladaptation. In addition, it is necessary to construct various coping methods and practical support systems, as well as to develop appropriate educational programs.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.6
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• pp.293-303
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• 2008

As the computing environment moves to the wireless and handheld system, the power efficiency is getting more important. That is the case especially in the embedded hand-held system and the power consumed by the memory system takes the second largest portion in overall. To save energy consumed in the memory system we can utilize low power mode of SDRAM. In the case of RDRAM, nap mode consumes less than 5% of the power consumed in active or standby mode. However hardware controller itself can't use this facility efficiently unless the operating system cooperates. In this paper we focus on how to minimize the number of active units of SDRAM. The operating system allocates its physical pages so that only a few units of SDRAM need to be activated and the unnecessary SDRAM can be put into nap mode. This work can be considered as a generalized and system-wide version of PAVM(Power-Aware Virtual Memory) research. We take all the physical memory into account, especially buffer cache, which takes an half of total memory usage on average. Because of the portion of buffer cache and its importance, PAVM approach cannot be robust without taking the buffer cache into account. In this paper, we analyze the RAM usage and propose power-aware page allocation policy. Especially the pages mapped into the process' address space and the buffer cache pages are considered. The relationship and interactions of these two kinds of pages are analyzed and exploited for energy saving.

• Journal of Society of Preventive Korean Medicine
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• v.9 no.2
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• pp.77-91
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• 2005

The purpose of this study is to examine the recognition of the student of oriental medical school on cooperative system between Oriental and Western medicine and to provide basic information for the development of oriental medicine. In order to look at the level of recognition on cooperative system between Oriental and Western medicine, from September 1st to 15th of 2005, this study had been conducted through personal interview and questionnaires to 600 students who were attending the Department of Oriental Medicine (in both prep and regular courses) in D University, located in the City of Daegu. The data has been analyzed using statistic program, the SPSS WIN 12.0. Statistical analysis tools used for this study were frequency analysis, cross-over analysis and the t-test. The results are as follows; The students of oriental medical school had relatively high level of recognition on the basic concept, interests, necessity and potential for cooperative system between Oriental and Western medicine. However, they had negative understandings on the issue of unification of the two medical systems and it's possibility in the future. The students were optimistic about possible merits of cooperative system between Oriental and Western medicine, especially in the field of rehabilitation. On the reasons for lack of development of cooperative system between Oriental and Western medicine, the students listed prejudices existing on both sides firstly, followed by their contrasting approach on human illness, lack of legal and institutional support system, the indifferences of doctors and indifferences of oriental medical doctors. In addition, students understood that the dualism existing in our current medical system is aggravating mutual distrust between the two sides, causing the confusion of patients on the choice of medical facilities, and raising their medical bills. Therefore, in order to vitalize collaboration between Oriental and Western medicine in new health care environment, the following measures should be needed decreasing the prejudices between the two medical spheres with open mind improving educational programs in Western and Oriental medical schools; promoting joint academic research or exchange programs between the schools, and increasing government effort to minimize legal and institutional restrictions cooperative system between Oriental and Western medicine.