• Current Optics and Photonics
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• v.4 no.6
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• pp.524-529
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• 2020

We propose a depth-fused-type three-dimensional (3D) near-eye display implemented using a birefringent lens set that is made of calcite. By using a birefringent lens and image source (28.70 mm × 21.52 mm), which has different focal lengths according to the polarization state of the incident light, the proposed system can present depth-fused three-dimensional images at 4.6 degrees of field of view (FOV) within 1.6 Diopter (D) to 0.4 D, depending on the polarization distributed depth map. The proposed method can be applied to near-eye displays like head-mounted display systems, for a more natural 3D image without vergence-accommodation conflict.

• Electronics and Telecommunications Trends
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• v.39 no.2
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• pp.24-32
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• 2024

Wearable metaverse devices have sparked enthusiasm as innovative virtual computing user interfaces by addressing a major source of user discomfort, namely, motion-to-photon latency. This kind of latency occurs between the user motion and screen update. To enhance the realism and immersion of experiences using metaverse devices, the vergence-accommodation conflict in stereoscopic image representation must be resolved. Ongoing research aims to address current challenges by adopting vari-focal, multifocal, and light field display technologies for stereoscopic imaging. We explore current trends in research with emphasis on multifocal stereoscopic imaging. Successful metaverse visualization services require the integration of stereoscopic image rendering modules and content encoding/decoding technologies tailored to these services. Additionally, real-time video processing is essential for these modules to correctly and timely process such content and implement metaverse visualization services.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.215-223
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• 2006

The Total Maximum Daily Load(TMDL) Act just implemented as a new tool of watershed based water quality management, in Korea. Thus, there are a number of pending questions to resolve for successful settlement of the TMDL. The allocation of pollution source is a exceedingly sensitive issue on local development planning. The simple area-based allocation (SAA) is conventional method to allocate the administrational pollution information to watershed based information. The SAA has a limitation that it can't consider the characteristics of spatial distribution of pollution source and it has caused more uncertainty of TMDL. This study was performed to reduce the uncertainty of watershed-based pollution information using the spatial distribution-based allocation(SDA). In the specific area where pollution source is concentrated such as urbanized region, it has been certified that SDA could reduce a tolerance of pollution information dramatically. As a result of study, SDA is expected a effective tool for TMDL and to solve the conflict between development and protection.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.447-456
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• 2015

In this paper a new model of storytelling related to patent in the field of business as a sort of Intellectual Property(IP) was proposed. The patent related storytelling is investigated in the view points of variety of customers, purposes and applications which is different from the conventional OSMU, transmedia or crossmedia storytelling. In business there are several stages related to patent such as the initial conceptualization and development of technology, apply for and registration of patent, legal conflict like patent invalidation trial and action for infringement of patent and damages, and the commercialization stage like development of product based on patent, advertisement and marketing. Multiple sources optimized to the purpose in each stage of patent related business as well as to multiple convergence application of a patent. Similarly, multi-use refers to the fact that storytelling can be applied in each stage of patent oriented business. The effectiveness and usefulness of proposed MSMU model is also investigated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1369-1376
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• 2015

A wireless bridge is essential to transmit control and managing information to sensors or instruments from a central integrated ship area network station. In this paper, a WiMedia Distributed-MAC(D-MAC) protocol is adopted for development of a seamless N-Screen wireless service in Indoor and Ship Area Networks. Furthermore, to provide the OSMU(One Source Multi Use) N-screen service through P2P streaming in the seamless D-MAC protocol, a Dynamic Threshold-based Multicast(DTM) technology is proposed and analyzed. For this technology, a new Hard/Soft Vertical Region(HVR-SVR) based time slot allocation and a multicast resource reservation scheme are combined. From simulation results, proposed DTM scheme expands the number of time slots available for unicast and multicast realtime N-Screen reservations with various service time interval requests. Furthermore, it enhances performances in vewpoints of realtime N-Screen data reservation conflict and throughput.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.204-209
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• 2007

Agricultural area in the vicinity of the ${\triangle}{\triangle}$ smelting factory in Kyeongbuk province, the third largest zinc smelting factory in the world, was contaminated by high concentration of heavy metals. However, the heavy metals source was not yet directly traced and thus, resulted to a conflict between the factory and residents within its vicinity. In order to determine the level of heavy metal contamination in the arable lands located at the north eastern part of the factory, soils were sampled systematically. To find out the major reason for the occurrence of this problem, waters and aerosols were sampled with constant intervals to the upward and downward direction from the factory and were analyzed to find out the heavy metal concentrations. Cadmium (Cd) and zinc (Zn) of the heavy metals were highly accumulated more than the Korean warning criteria (Cd 1.5, Zn 300 mg $kg^{-1}$) with mean values 1.7 and 407 mg $kg^{-1}$, respectively, at the surface soils (0-20 cm), and heavy metal concentration significantly decreased with increasing soil depth In addition, the concentration of both metals slightly decreased with increasing distance from the factory to the surface soils. Cadmium and Zn were detected in the upward stream water with low concentration and concentrations increased significantly in the downstream after passing across the factory. Aerosol samples also showed traces of Cd and Zn which could be attributed to the contamination of the water system and the surface soils. Conclusively, Cd and Zn emitted from the ${\triangle}{\triangle}$ smelting factory moved with the aerosol in the atmosphere and thus, contaminated the agricultural areas and the water system within it vicinity.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.27-33
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• 2014

The significance of soil environment is gradually increased due to the soil and underwater contamination caused by petroleum leak accidents. It requires a high cost and long period for the purification of soil compared with other environmental matrix such as water and air. For this reason, it has been embroiled in a legal conflict to find the pollution source and charge of cleanup. In this study, we analyzed the physical properties and typical additives of jet fuel to search a method that can distinguish kerosene and jet fuel contamination. In particular, the chemical marker in kerosene was visualized by the developer and the additives in jet fuel, such as antioxidant and metal deactivator were detected by GC-MS. This study could be used to judge petroleum source at soil contaminant accident sites.

• Journal of Forest and Environmental Science
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• v.38 no.1
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• pp.1-11
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• 2022

The Dutch colonial government introduced social forestry at the end of the 19th century with a commitment to controlling forest resources in the Dutch East Indies. This program was a response to the rampant deforestation which had resulted in forest degradation and poverty of the population around the forest. This study examined the practice of social forestry in the late colonial period which had not been done much. From a historical perspective, social forestry practices in Indonesia before independence could be explained more comprehensively. This study uses a historical method which includes four stages: heuristic, source criticism, interpretation, and historiography (composing historical stories). Sources of information were explored through studies of archival documents and contemporary artefacts, especially official colonial government reports and contemporary newspapers/magazines. Data from various sources are then compared and tested for validity to obtain data validity. The next stage is to build facts based on data obtained and then interpreted using the social science theories. Finally, compiling a historical (historiographical) story about social forestry during the late colonial period. The results showed that colonial forestry during the colonial period was still limited in terms of area and method, namely in the area of teak forest and involving villagers through the intercropping system. Farmers involved in these activities are called pesanggem who earn income from forest land being rejuvenated. However, the relationship between pesanggem and the forestry service has not been well institutionalized, consequently the pesanggem is often disadvantaged. Including certainty of ownership and ownership of forest land never gained clarity and even became a source of conflict.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.634-643
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• 2011

The neutral section was installed in order to prevent conflict with different phase angle source in electric railway catenary system. The speed of electric train reduced due to coasting operation by notch off when it passed the neutral section. And, the catenary wire was damaged and the accident might be happened because of the arc generation when the electric train passed the neutral section with notch off condition. The inrush current of main transformer installed tiling train is analyzed during the operation of MCB(main circuit break) passing through the neutral section. The instantaneous waveform of load current were analyzed in case of powering and regenerative braking. Inrush current waveform with run of AC railway train showed that inrush current waveform and harmonics, the inrush current generated from main transformer in train has bad effects on power quality problem. In order to reduce these inrush currents, the MCB is connected when the phase angle of voltage is 90 degree. This paper is to measure inrush current and harmonics in main transformer of high speed train in neutral section of electric railway. This measurement report is used to control minimum inrush current in algorithm and power phase angle.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.3
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• pp.1-21
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• 2015

Customer firms exercise various sources of power to influence their suppliers' behaviors or decisions. In this study we aim to examine the effects of customers' sources of power on their supplier's performance improvement. This study posits that a customer's expert, referent, and reward power positively influence a supplier's performance directly as well as indirectly through increased supplier-customer integration. On the contrary, the customer's coercive power is expected to worsen the supplier's operational performance because of increasing distrust, dissatisfaction, and conflict with the customer. Data collected from 1,229 firms from Korea, China, Hong Kong, Taiwan, and the U.S. are used to test the hypotheses. Expert power proves to be the most effective source of customer power in improving a supplier's inventory cost, delivery, and flexibility performance. In contrast, coercive power deteriorates significantly all supplier performance variables. Academic and managerial implications are presented and future research directions are also discussed.