• Economic and Environmental Geology
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• v.50 no.2
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• pp.159-170
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• 2017

The temporal and spatial temperature distribution of the heat storage mortar made of porous feldspar was measured and the thermal properties and electricity consumption were analyzed. For the experiment, two real size chambers (control model and test model) with hot water pipes were constructed. Two large scale models with hot water pipes were constructed. The surface temperature change of the heat storage layer was remotely monitored during the heating and cooling process using infrared thermal imaging camera and temperature sensor. The temperature increased from $20^{\circ}C$ to $30^{\circ}C$ under the heating condition. The temperature of the heat storage layer of the test model was $2.0-3.5^{\circ}C$ higher than the control model and the time to reach the target temperature was shortened. As the distance from the hot water pipe increased, the temperature gap increased from $4.0^{\circ}C$ to $4.8^{\circ}C$. The power consumed until the surface temperature of the heat storage layer reached $30^{\circ}C$ was 2.2 times that of the control model. From the heating experiment, the stepwise temperature and electricity consumption were calculated, and the electricity consumption of the heat storage layer of the test model was reduced by 66%. In the cooling experiment, the surface temperature of the heat storage layer of the test model was maintained $2^{\circ}C$ higher than that of the control model. The heat storage effect of the porous feldspar mortar was confirmed by the temperature experiment. With considering that the time to reheat the heat storage layer is extended, the energy efficiency will be increased.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.21-32
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• 2018

This study was carried out to define the characteristics of the identified ground-dwelling invertebrate communities at Nari basin and Tonggumi area in Ulleungdo Island, designated as a nationally important agricultural heritage. The habitat types were divided into the following categories: crop land, forest, and ecotone, and the soil-dwelling invertebrates were collected according to habitat type. The ground-dwelling invertebrates were collected using a pitfall trap, and a self-organizing map (SOM) was applied to the invertebrates dataset to define the characteristics in invertebrates distribution. The SOM clearly classified the relevant information into four clusters, and extracted ecological information from the invertebrates dataset. The cluster II was composed of invertebrate communities which are collected in the Tonggumi area. The Tonggumi area is where mountainous areas were developed for agricultural purposes, which has geographical features commonly observed in Ulleungdo Island. It is noted that the cluster II has different characteristics as compared other clusters. The results of this study are expected to be used for the preservation of agricultural environment and maintenance of biodiversity by providing basic data, on the biotope of Ulleungdo Island designated as a nationally important agricultural heritage and information on the characteristics of the applicable ground-dwelling invertebrate communities.

• Journal of the Korean Society for information Management
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• v.22 no.2 s.56
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• pp.125-145
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• 2005

This paper presents a semantic vector space retrieval model incorporating a word sense disambiguation algorithm in an attempt to improve retrieval effectiveness. Nine Korean homonyms are selected for the sense disambiguation and retrieval experiments. The total of approximately 120,000 news articles comprise the raw test collection and 18 queries including homonyms as query words are used for the retrieval experiments. A Naive Bayes classifier and EM algorithm representing supervised and unsupervised learning algorithms respectively are used for the disambiguation process. The Naive Bayes classifier achieved $92\%$ disambiguation accuracy. while the clustering performance of the EM algorithm is $67\%$ on the average. The retrieval effectiveness of the semantic vector space model incorporating the Naive Bayes classifier showed $39.6\%$ precision achieving about $7.4\%$ improvement. However, the retrieval effectiveness of the EM algorithm-based semantic retrieval is $3\%$ lower than the baseline retrieval without disambiguation. It is worth noting that the performances of disambiguation and retrieval depend on the distribution patterns of homonyms to be disambiguated as well as the characteristics of queries.

• The Korean Nurse
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• v.30 no.1
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• pp.51-62
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• 1991

The Study was carried out for the purpose of investigating the degree of perception in nursing activities. This study reports perceptions of nurses on the choices they make among competing activities, contrasts this perception with their opinion of what tasks they would like to spend time on. A sample of 231 clinical nurses was selected to participate in this study at two genernal hospitals in Seoul. The data was collected from July 10th to 25th, 1990. Subjects were instructed to rate one of five points likert type scale on the 43 items of nursing activities. Analysis of data was done by means of the SPSS-X Program using frequency, t-test and ANOVA. The results of this study were as follows; 1. The characteristics of the subjects were as follows: The age group of 25-29 yeares was 45.9%. For religion, Christians had the highest score, 68.4 % and singles in subjects were 81.4%. For academic background, 64.5% were graduated from nursing junior colleges. In the subjects, staff nurses were 86.6%. 22.5% of them had worked for less than 1 year and 20.8% had 37 months to 5 years experience at the time of the survey. 62.8% were satisfied with the job. 2. The perception level of nursing activities: 1) The mean score for perception of professional nursing functions was 4.157 point, with a maximum score set. at 5 points. The mean score for perception of priorities was 3.781. Perception of spending time was 3.932. 2) In perception of professional nursing functions, more important items were Aseptic technique (4.866), Shift and exchange of information concerning patients(4.654), Observing patients (4.799). Less important items were Transporting patients(3.411), Changing linens(3.442), Giving a bed shampoo (3.506). In priorities, more important ones. were Aseptic technique(4, 706), Shift and exchange of information concerning patients (4.524.), Observing patients(4.390), Taking vital signs (4.355). And less important ones were Changing linens (3.100), Giving bed baths(3.113), Giving back rubs(3.121). In spending time, more important ones were Aseptic technique(1.706), Observing patients (4.532), Shift and exchange of information concerning patients(4.532). And less important ones were Changing lines(3.368), Transporting patients(3.394), Giving bed baths(3.450). 3) In the role perception level, the mean distribution of perception was 3.511- 4.335; the role was perceived to be in order of frequency as a facilitator, coordinator, change agent and advocator role. The most important scale of factors by nursing activities was indirect nursing activities.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.583-594
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• 2002

Assuring the security of group communications such as tole-conference and software distribution requires a common group key be shared among the legal members in a secure manner. Especially for large groups with frequent membership change, efficient rekey mechanism is essential for scalability. One of the most popular ways to provide sealable rekey is to partition the group into several subgroups. In this paper, we propose a two-layered key management scheme which combines DEP and CBT, a protocol in which subgroup manager cannot access the multicast data and another that has a multi-core, respectively. We also select sub-group key management protocols suitable for our structure and design new rekey protocols to exclude the subgroup managers from the multicast data. Compared to previous protocols based on CBT, our scheme provides forward secrecy, backward secrecy and scalability. This would reduce the number of encryption and decryption for a rekey message and would improve the efficiency number of rekey messages and the amount of information related to group members that group managers must maintain compared to DEP.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1359-1365
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• 2008

The portion of header in H.264 gets higher than those of previous standards instead of its better compression efficiency. Therefore, this paper proposes a new technique to compress the header of H.264. Unifying a sentence elementary in H.264, H.264 does not consider the distribution of element which be encoded and uses existing Exp-Golomb method, but it is uneffective for variable length coding. Most of the header are block type(s) and motion vector difference(s), and there are redundancies in the header of H.264. The redundancies in the header of H.264 which are analyzed in this paper are three. There are frequently appearing symbols and non-frequently appearing symbols in block types. And when mode 8 is selected in macroblock, all of four sub-macroblock types are transferred. At last, same values come in motion vector difference, especially '0.' This paper proposes the algorithm using type code and quadtree, and with them presents the redundant information of header in H.264. The type code indicates shape of the macroblock and the quadtree does the tree structured motion compensation. Experimental results show that proposed algorithm achieves lower total number of encoded bits over JM12.4 up to 32.51% bit reduction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.801-809
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• 2010

Limitation of optical phase conjugation for implementation of wideband and long-haul WDM transmission system is symmetric distribution of optical power and local dispersion with respect to optical phase conjugator (OPC). This limitation forces OPC to place at midway of total transmission length. This paper shows that the limitation of optical phase conjugation is overcame by applying optimal net residual dispersion (NRD) into transmission links based in inline dispersion management (DM). Optimal NRD related with OPC position is decided by combination of precompensation and postcompensation. It is confirmed that optimal NRD depends on launch power of WDM channels and system performance criterion as well as OPC position. That is, in case of 1 dB eye opening penaty (EOP) as a performance criterion for WDM channels with 0 dBm launch power, it is confirmed that OPC is allowed to place at anywhere of 1000 km by applying best NRD related with exact OPC position into transmission links. And, it is confirmed that, under 3 dB EOP criterioin for WDM channels with 3 dBm launch power, OPC is allowed to place at 350~700 km by applying NRD between 100 ps/nm and 200 ps/nm into transmission links, though that NRD value is not best combination of precompensation and postcompensation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.77-84
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• 2018

As the application of BIM (Building Information Modeling) to the civil sector has become practical, and mandatory for road projects, the standardization, development of systems, etc. for the application and operation of BIM are required. In particular, it is important to develop BIM data standards for producing, sharing and managing the lifecycle data of civil facilities because they are commonly national public facilities. The BIM data standards have been developed by utilizing or extending IFC (Industry Foundation Classes), which is an international standard, but schema extensions of river facilities has not been developed thus far. This study proposes an approach to an IFC extension for river facilities using the WBS (Work Breakdown Structure) as a fundamental study for IFC-based schema extension in the river field. For this purpose, the research was carried out as follows. First, the IFC extension development method was selected to represent the river facilities by analyzing the existing IFC structure and previous research cases for the IFC extension. Second, extended elements of the river facilities were identified through an analysis of the WBS and classified according to the high-level structure of the IFC schema. Third, the classified elements were arranged based on the IFC hierarchy and the IFC schema extension for river facilities was established. Based on the suggested extension method of IFC schema, this study developed the schema by defining the element components and parts of river facilities, such as distribution flow elements and deriving their detailed types and properties.

• Hwankyungkyoyuk
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• v.14 no.2
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• pp.76-94
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• 2001

Promoting positive values, attitudes, participation and personal actions on the basis of the acquisition of one's knowledge and skills is emphasized on teaching environmental education. To complete this purpose of environmental education, it is necessary not only to use various and practical educational resources, but also to develop information system, with multimedia and internet, which are effective for learning. This research attempts to assess the consistency of planning, organization and operation of integrated program for social environmental education which was developed for the necessities mentioned above. We surveyed about the accuracy of contents, usefulness, convenience and easiness of Integrated program for social environmental education. Also, we used a questionnaire to clarify the values and attitudes of respondents after they took environmental education. Then, technically, descriptive statistical method has been used to analyze the results of these surveys. Finally, we conduct an examination of the distribution of chi-square to verify the relationship between the learner's experience of using computer and one's concern about environmental issues. The results of this program, developed by research team, can be assessed by following five basic elements: usefulness, practicality, appropriation, efficiency and effectiveness. More than 90% of respondents said that this program is convenient and easy to loam. Also, more than 85% of whole respondents identified that after teaming this program they recognized more clearly what the main contents of environmental education are. In addition, we got positive response from 93% of respondents that they could understand environmental problems. On the other hand, values and attitudes of respondents have not improved a lot after the environmental education compared with the remarkable change in their recognition and understanding of environmental issues; only 34% of respondents responded that they changed their life style for making better environment after teaming this program. But it is clear that they understand much better about the environmental policy after they are educated. Developed by using information system, this integrated program for social environmental education may get different results according to a respondent's experience of using computer. Therefore, the more a respondent got a chance to use computer for a long period of time, the more he/she gave positive evaluation on the convenience and easiness of this program. However, there was no certain relationship between the frequence of using computer and one's understanding of environmental issues. Futhermore, a person who has constant concerns about environmental problems showed more positive attitudes against the understanding of environmental education. This integrated program for social environmental education, characterized by integrated, specialized and efficient educational system, can also be used as a curriculum or teaching materials for environmental education for adults; especially, it would be appropriate for teaching learners at all levels, who have different personal characteristics, to let them acquire virtual education by using information system.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.31-41
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• 2012

Due to growing interests in the distribution of traffic volume through information dissemination such as VMS and traffic broadcasting system, the research on the driver's reaction and effect of the traffic report has continued. In this study, we propose a methodology, which estimates the traffic volume of diversion and the consequential diversion rate using FTMS data and TCS data, and the estimation is based on the analysis of the national highway and IC, in which real-time FTMS and TCS data are established. We also calculate the diversion rate of actual targeted sections and analyze the changes in time and spatial diversion rate. In this study, we define a deviation (considering a deviation due to dynamic properties of traffic conditions) found when the outflow traffic volume is temporarily higher than the average outflow traffic volume on a relevant time slot after providing traffic information. The diverting volume is considered to be caused by the traffic information, and the study determines the ratio of traffic volume on highways to that of route diversion as the diversion rate. The analysis on changes in the diversion rate in accordance with the time flow, the initial change in the diversion rate on upstream IC that first acquires the report on the traffic congestion is significant. After that, the change in the diversion rate on upstream IC affects the route diversion on downstream IC with spatial and time flow, and this again leads the change in upstream IC. Thereby, we confirmed that there is a feedback-control circulation system in the route diversion.