• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1785-1795
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• 2013

Most of the previous models for analysis of shallow water flow assumed the uniform velocity distributions over the flow depth so that they produced incorrect velocity prediction at meandering part due to the ignorance of secondary current. In this study, the vertical velocity profiles in longitudinal and transverse direction were decomposed as the mean and variation components, which resulted in additional dispersion stresses terms in momentum equations. The proposed model were applied at the channels with $30^{\circ}$, $90^{\circ}$, $270^{\circ}$ bends, and shallow water flow in curved channel was analyzed using dispersion stresses. The dispersion stresses acted as a sink or source in the momentum equations, which caused the transverse convection of momentum to shift from the inner bank to the outer bank.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.5
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• pp.1390-1411
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• 2024

Underwater Wireless Sensors Networks (UWSNs) are deployed in remotely monitored environment such as water level monitoring, ocean current identification, oil detection, habitat monitoring and numerous military applications. Providing scalable and efficient routing is very challenging in UWSNs due to the harsh underwater environment. The biggest difficulties are the nodes inherent movement due to water current, long delay in data transmission, low bandwidth of the acoustic signal, high error rate and energy scarcity in battery powered nodes. Many routing protocols have been proposed to solve the aforementioned problems. There are three broad categories of routing protocols namely depth based, energy based and vector-based routing. Vector Based Forwarding protocols perform routing through virtual pipeline by defining their radius which give proper direction to packets communication. We proposed a routing protocol termed as Path-Oriented Energy Scaled Expanded Vector Based Forwarding (PESEVBF). PESEVBF takes into account all parameters; holding time, the source nodes packets routing path and void holes creation on the second hop; PESEVBF not only considers the packet upward advancement but also focus on density of the forwarded nodes in terms of number of potential forwarding and suppressed nodes for path selection. Node selection in resultant holding time is based on minimum Path Factor (PF) value. Moreover, the suppressed node will be selected for packet forwarding to avoid the void holes occurrences on the second hop. Performance of PESEVBF is compared with other routing protocols using matrices such as energy consumption, packet delivery ratio, packets dropping ratio and duplicate packets creation indicating considerable performance improvement.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.188-199
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• 2019

In this study, research trends were investigated by examining important academic research on museum lighting that has been carried out in Korea over the past 30 years. The aim was to highlight important studies conducted in Korea on material deterioration caused by museum lighting and to examine the current status of research on LED light sources to provide direction for future research. The ultimate goal of studies on museum lighting is to improve the long-term conservation effects, and this study examined the latest light sources of each era. Prior to the 1990s, the effects of light sources on relics were assessed by investigating incandescent light bulbs and fluorescent lamps, the first museum exhibition lighting. Then in the 1990s, the introduction of halogen lamps and HID lamps led to the analysis of the characteristics of a light source itself and the introduction of illumination standards. In the 2000s, the lighting environment of museums was investigated based on the characteristics of the light sources that had been studied, and in terms of preservation, research was conducted not only to improve the conservation of relics but also to improve the sentiments of visitors. After 2010, LED lamps were introduced; therefore, material deterioration studies on LED lamps were expanded. During this period, enhancements to LED light sources were made, such as reducing the blue spike area and increasing color rendering. With the development of lighting used in museums and art galleries, the direction of the display preservation criteria has led to the need to prepare advanced standards, covering all aspects from the center of illumination to the consideration of the color of an object and the speed of radiation from the light source. Regular studies of museum lighting in a long-term perspective should be planned to standardize the more advanced conditions of material discoloration.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.47-53
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• 2003

In this paper, we described the laboratory layout of the optical CT in connection with the measurement of large current based on Magneto-Optic Effects. It was used He-Ne laser for light source and was used PIN-Photodiode for light receiver. The sensing section was organized by winding optical fiber around conductor on the concept that the rotation angle of polarizing axis by Faraday Effect is proportional to the applied current in to conduction. The optical signal passed through optical fiber sensor was induced to analyzer arranged in the direction of $\theta$ for input polarization, and then analyzed its rotation angle and researched on operating characteristics of optical CT for 60[Hz] AC current measurement from l00[A] to 1000[A] was carried out. In this results, the output signals induced linearly with the current and proved that the intensity is increased with increasing turns of fiber through output differences which in accordance with turns of fiber and we verified that there is not only difference of the output with the medium between electric field and optical fiber, but also the lineality. Measuring the references and output intensities of the optical CT, ratio errors were within $\pm$7%. This confirmed that error rate will be improved by each medium and turns.

• The Journal of Society for e-Business Studies
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• v.20 no.3
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• pp.29-46
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• 2015

Examined how it varied the knowledge network of the country along with R&D changes in planning policy for the research and development of government. Therefore, in this study, chronological Analysis analyzed separately the network between each entity of participate in the industry fusion source technology development business of industry trade and Energy. Planning policy of industrial fusion source technology development business, to change the starting point before and after 2012, before 2012 from selected planning issues at the center "planning committee" and in 2012 'PD' changes to a system for planning issues around. First of all, an attempt to analyze the R&D network based on the "planning committee" current situation of 2009~2011, from 2012 to analyze the variation of the R&D network with the introduction of the 'PD' system after it was analyzed by dividing the time in the current state of up to 2013. The results of the analysis, since the PD system was introduced, such as self-relationship (the form of planning user to run directly challenges the person was planning to challenge participants)is greatly improved, I was able to grasp the effect became clear. The more the self-relation, and the budding scholars considering that there is inequality of the planning, the introduction of the PD scheme, it can be seen to have resulted in a positive effect. These studies, quantitatively analyzed to improve the results to the effects associated with changes in the planning policy of the government, I think that there is a meaning in terms of presenting the future direction of R&D policy.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.1
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• pp.44-52
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• 2014

The purpose of this study is to investigate the tendency of the research on the traditional scenery architecture based on the old literature for the last 10 years and to suggest direction of the research on the traditional scenery through utilization of the old literature. For the tendency analysis of the research on the traditional scenery, I investigated and analyzed researches published in the Journal of the Korean Institute of Traditional Landscape Architecture between 2002 and 2012, and reviewed the utilization of the old literature about research on the traditional scenery. The number of the research papers through the old literature was two or three a year by 2009, but has increased to more than eight from 2010. The utilization tendency of the old literature was mostly to use the Korean translations or to use a collection of an individual's works after partially translating. As some of the researches were carried out only through translations even when they used the original, historical evidence on the translation of the original was insufficient. I can suggest the direction of the research on the traditional scenery by the results as follows: it is necessary to present both translation and the original and to specify the source of translation, for the efficient understanding and verification of the original. Professional translation of landscape architecture and scenery also seems to be necessary for the records of the current state. For the analysis of the old literature, as the analysis of the traditional scenery both through poetry and records facilitates assumption of the location of landscape by the abundant data, it seems to be necessary to approach research, using poetry and prose complementarily, after preparing foundation of research based on the records.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.487-496
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• 2001

In this study, a galvanic stimulator providing bipolar mode controlled by a PIC(peripheral interface controller) was constructed to evaluate vestibular function The maximum load and maximum current intensity of the constant current source were 3$k\Omega$ and 5mA. respectively. and it could Produce DC, sine wavers. or Pulse waves. Eve movements of 20 normal subjects by galvanic stimulation were analyzed using a commercial videooculogragh. During stimulating with DC for 30 sec. we recorded the response of eye movement with current intensity of 0.75. 1 2, and 3 mA. Nystagmus occurred to all the subjects when the galvanic stimulus intensity was larger than 2 mA. Average SPV(slow Phase eye movement velocity) and the number of nystagmus increased from 7.1 to 4.8 deg/sec and from 17 to 48, respectively, when the stimulus current increased from 0.75 to 3 mA. All the fast eye movement of the nystagmus were the direction of the negative electrode. The asymmetry which means the difference between right- and left-eye movements decreased when the stimulus intensity increased. It is expected that this study would be useful in evaluating vestibular function and in studying basic Physiology mechanism of vestibular ocular reflex by galvanic stimulus .

• Information Systems Review
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• v.12 no.1
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• pp.1-22
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• 2010

Demands onenterprise applications are changing drastically in terms of service and value. Currently enterprises have started to view these applications as service systems, as they combine technology with organizational networks designed to deliver services that satisfy the needs of customers and marketing operations. Social networking is playing a crucial role in this direction and provides organizations with the critical data that enable to build strong relationships with their customers and partners. Enterprises have started using this concept, by integrating social networking services with their enterprise applications such as CRM. In this paper, we combine an open source social networking engine with a CRM (Customer Relationship Management) application to constitute a social CRM system. This can bring the customers closer to the enterprise and facilitate better communication with them. Social Networking Analysis constructs were used to analyze the effectiveness of service system. In the current competitive and economically challenging conditions, salespeople needs to quickly and effectively establish meaningful communication with customers. Our approach can address this issue, by handling the changing customer demands in minimal time, and increases service quality and business value.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.289.2-289.2
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• 2016

In-Ga-Zn-O(IGZO) receive great attention as a channel material for thin film transistors(TFTs) as next-generation display panel backplanes due to its superior electrical and physical properties such as a high mobility, low off-current, high sub-threshold slope, flexibility, and optical transparency. For the purpose of fabricating high performance IGZO TFTs, a thermal recovery process above a temperature of $300^{\circ}C$ is required for recovery or rearrangement of the ionic bonding structure. However diffused metal atoms from source/drain(S/D) electrodes increase the channel conductivity through the oxidation of diffused atoms and reduction of $In_2O_3$ during the thermal recovery process. Threshold voltage ($V_{TH}$) shift, one of the electrical instability, restricts actual applications of IGZO TFTs. Therefore, additional investigation of the electrical stability of IGZO TFTs is required. In this paper, we demonstrate the effect of Ti diffusion and modulation of interface traps by carrying out an annealing process on IGZO. In order to investigate the effect of diffused Ti atoms from the S/D electrode, we use secondary ion mass spectroscopy (SIMS), X-ray photoelectron spectroscopy, HSC chemistry simulation, and electrical measurements. By thermal annealing process, we demonstrate VTH shift as a function of the channel length and the gate stress. Furthermore, we enhance the electrical stability of the IGZO TFTs through a second thermal annealing process performed at temperature $50^{\circ}C$ lower than the first annealing step to diffuse Ti atoms in the lateral direction with minimal effects on the channel conductivity.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.580-585
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• 2009

Harmful Algal Blooms (HABs), caused by Cochlodinium polykrikoides that causative fishery mortality, impact on aquaculture and economic loss appear particularly in summer and fall seasons in the Korean seas. It was studied on characteristics of HABs in the South Sea of Korea by using satellite and in-situ data. The in-situ data encompassed oceanic and meteorological data from July to October 2002-2008 and satellite data from July to October 2002-2006. Chlorophyll concentrations were calculated using Seaviewing Wide Field-of-view Sensor images by an Ocean Color (OC4) algorithm, and HABs were estimated using the Red tide index Chlorophyll Algorithm (RCA). The HAB occurrences were dominant when water temperature was $22.6-28^{\circ}C$ in August. The frequency of the individual numbers during 2002-2008, the HABs more than 1000 cells/ml (alert condition), were 73.57 %. In meteorological data from July to September during 2002-2008, the average precipitation, the mean air temperature, the mean wind speed and direction, and the sunshine were 9.31 mm/day, $24.07^{\circ}C$, 2.34 m/s and easterly, and 1-11 h, respectively. Our results suggest that the upwelling is caused by southwesterly wind in summer season and the Tsushima Warm Current which have influenced on the dispersion and moving of HAB (chlorophyll). In addition, the fresh water from Nakdong River, as the source of nutrients, also influences the occurrence of HABs.