• Ocean and Polar Research
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• v.33 no.1
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• pp.85-97
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• 2011

The tidal flats of Korea today have reduced by 40% in size compared to 1964. To manage this important habitat properly, development of well-organized and nationwide-applicable grading systems is required. There have been several assessment systems proposed previously in Korea, but they are critically flawed in that selected biological indicators are not adequate and grading criteria are obscure and arbitrary. We reviewed the indicators used in these previous evaluation systems (e.g., diversity indices, quantity and quality of benthic macrofauna, halophytes, water birds, etc.) and subsequently proposed new indicators and an improved grading scheme. For the quantitative assessment of macrobenthic community, biomass reflecting production and ecosystem function is recommended over density, which is much less discriminatory among habitats. Of biodiversity indices used, within-, between-habitat and regional biodiversity indices that accurately reflect sampling efforts are suggested. In addition, we proposed to include species rarity, ecosystem engineers, and the ecological quality index ISEP (Inverse function of Shannon-Wiener Evenness Proportion). As for halophytes, their low spatial coverage on benthic habitat suggests that their presence can be used as an ecological indicator of benthic habitat, regardless of their protective status. We stress the need to introduce 1) quantile approach for quantitative indicators (e.g., diversity, biomass, etc.) in relation to grading, 2) presence-absence approach for spatial or aggregate indicators (e.g., boundaries of halophytes and feeding ground of water birds) and 3) benthic habitat mapping that combines all of these indicators.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9B
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• pp.602-609
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• 2005

In this paper, the performance of HCS (hierarchical cell structure), which consists of macro-cell and micro-cell, has been analyzed by assuming that the cells in HAPS (high altitude plat(on station) are tessellated to provide wide coverage, control the co-channel interference and give the higher spectrum efficiency. Since the outside-cell interference factor is well blown to analyze the effects of interference between cells, the effects of interference from the micro-cells into the macro-cells has been estimated using the factor as a performance estimation of HCS in HAPS. HCS served by HAPS can be realized by permitting the suitable power control and the proper number of users in micro-cell because the interference from the micro-cell into the macro-cell is not a function of the distance between cells but a function of the power control and the number of users.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.131-138
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• 2008

Mobile Ad hoc NETworks (MANETs) refer to autonomous networks in which wireless data communications are established between multiple nodes in a given coverage area without a base station or centralized administration. Because of node mobility and limited battery life, the network topology may changes frequently. Selecting the most reliable path during route discovery process is important to improve performance in ad hoc networks. In this paper, an enhanced routing protocol based on AODV(Ad hoc On-demand Distance Vector routing) by monitoring variation of receiving signal strength is proposed. New metric function that consists of node mobility and hops of path is used for routing decision. For preventing route failure by node movement during data transmission, a new route maintenance named as LRC (Local Route Change) is presented. If the node movement is detected, the routing agent switches path to its neighbor node in LRC. Simulation results show that the performance of the proposed routing scheme is superior to previous AODY protocol.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.380-380
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• 2010

Currently, organic light-emitting diodes (OLEDs) have been proven of their readiness for commercialization in terms of lifetime and efficiency. In accordance with emerging new technologies, enhancement of light efficiency and extension of application fields are required. Particularly inverted structures, in which electron injection occurs at bottom and hole injection on top, show crucial advantages due to their easy integration with Si-based driving circuits for active matrix OLED as well as large open area for brighter illumination. In order to get better performance and process reliability, usually a proper buffer layer for carrier injection is needed. In inverted top emission OLED, the buffer layer should protect underlying organic materials against destructive particles during the electrode deposition, in addition to increasing their efficiency by reducing carrier injection barrier. For hole injection layers, there are several requirements for the buffer layer, such as high transparency, high work function, and reasonable electrical conductivity. As a buffer material, a few kinds of transition metal oxides for inverted OLED applications have been successfully utilized aiming at efficient hole injection properties. Among them, we chose 2 nm of $WO_3$ between NPB [N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] and Au (or Al) films. The interfacial energy-level alignment and chemical reaction as a function of film coverage have been measured by using in-situ ultraviolet and X-ray photoelectron spectroscopy. It turned out that the $WO_3$ interlayer substantially reduces the hole injection barrier irrespective of the kind of electrode metals. It also avoids direct chemical interaction between NPB and metal atoms. This observation clearly validates the use of $WO_3$ interlayer as hole injection for inverted OLED applications.

• Journal of the Korean Medical Association
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• v.61 no.12
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• pp.724-731
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• 2018

Our faces can express a remarkable range of subtle emotions and silent messages. Because the face is so essential for complex social interactions that are part of our everyday lives, aesthetic repair and restoration of function are an important tasks that we must not take lightly. Soft-tissue defects occur in trauma patients and require thorough evaluation, planning, and surgical treatment to achieve optimal functional and aesthetic outcomes, while minimizing the risk of complications. Recognizing the full nature of the injury and developing a logical treatment plan help determine whether there will be future aesthetic or functional deformities. Proper classification of the wound enables appropriate treatment, and helps predict the postoperative appearance and function. Comprehensive care of trauma patients requires a diverse breadth of skills, beginning with an initial evaluation, followed by resuscitation. Traditionally, facial defects have been managed with closure or grafting, and prosthetic obturators. Sometimes, however, large defects cannot be closed using simple methods. Such cases, which involve exposure of critical structures, bone, joint spaces, and neurovascular structures, requires more complex treatment. We reviewed and classified causes of significant trauma resulting in facial injuries that were reconstructed by microsurgical techniques without simple sutures or coverage with partial flaps. A local flap is a good choice for reconstruction, but large defects are hard to cover with a local flap alone. Early microsurgical reconstruction of a large facial defect is an excellent choice for aesthetic and functional outcomes.

• Journal of Forest and Environmental Science
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• v.34 no.6
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• pp.481-489
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• 2018

In this study, the succession and stand dimension attributes related to the disaster prevention function of Pinus thunbergii coastal forests were examined after damage from Diplodia tip blight. In 2015, 101 years after the Taisho eruption, field investigations were performed on the vegetation, soil thickness, and pH of surface soil of P. thunbergii coastal forests in western Sakurajima (Hakamagoshi plot) and Taisho lava flows in southeastern Sakurajima (Seto plot). The Hakamagoshi plot had more woody plant species with larger basal areas than that in the Seto plot. The mean age and height, maximal age and height of plant species, and H/D ratio were all larger in the Hakamagoshi plot than in the Seto plot. These results may be explained by the relatively smaller effect of volcanic ash and gas on forests in the Hakamagoshi plot compared to the Seto plot, resulting in a more suitable environment for many plant species. Although P. thunbergii coastal forests in Sakurajima are currently recovering from damages owing to Diplodia tip blight, there has not yet been a sufficient recovery compared to the results from a 1997 study. Furthermore, the results of assessment based on the H/D ratio and abundance of trees in P. thunbergii forests indicate that both regions are not yet effective in disaster prevention. Thus, it is necessary to establish Pinus trees, which can adjust to harsh environments like coastal areas and are resistant to volcanic ash and gas, to enhance the disaster prevention function of P. thunbergii coastal forests in volcanic regions. It may also be helpful to establish coastal forests with ectotrophic mycorrhizal fungi and organic matter coverage. Additionally, it is necessary to ensure the continuous maintenance of stand density and soil quality, and further develop efforts to prevent Diplodia tip blight and promote forest recovery.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.72.3-72.3
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• 2015

We present the mid-infrared (MIR) luminosity function (LF) of local (z < 0.3) star forming (SF) galaxies based on the AKARI's NEP-Wide Survey data. We utilized a combination of the NEP-Wide point source catalogue containing a large number (114,000) of infrared (IR) sources distributed over the wide (5.4 sq. deg) field and spectroscopic redshift (z) data for 1790 selected targets obtained by optical follow-up surveys with MMT/Hectospec and WIYN/Hydra. The AKARI's continuous $2{\sim}24{\mu}m$ wavelength coverage and the spectroscopic redshifts for sample galaxies enable us to derive accurate spectral energy distributions (SEDs) in the mid-infrared. We carried out SED-fit analysis and employed 1/Vmax method to derive the mid-IR (e.g., $8{\mu}m$, $12{\mu}m$, and $15{\mu}m$ rest-frame) luminosity functions. Our results for local galaxies from the NEP region generally consistent with various previous works for other fields over wide luminosity ranges. The comparison with the results of the NEP-Deep data implies the luminosity evolution from higher redshifts towards the present epoch. We attempted to fit our derived LFs to the double power-laws and present the resulting power indices. We also examined the correlation between mid-IR luminosity and total IR luminosity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.189-197
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• 2012

It is usual for test data generation to be performed using either high-level specifications or source codes written in high-level programming languages. In certain circumstances, however, such information is not always available. This paper presents a technique that generates test data based on executable object codes. The proposed technique makes use of a very simple function minimization technique without sophisticated object code analysis and produces test data dynamically. We have conducted a simple experiment to evaluate the effectiveness of the proposed test data generation technique with a triangle classification program to show that branch coverage can be easily achieved.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.325-330
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• 2017

In the case of single tooth replacement, a fixed prosthesis or a dental implant is the treatment option commonly selected as first choice. However, any amount of sound tooth structure should be removed to prepare the abutment teeth for full coverage retainer. The adjacent tooth damage can be avoided placing a dental implant. However, depending on the patient's oral condition and any other circumstances, it may be impossible or delayed. In this case resin bonded fixed partial denture was selected as an alternative that can restore single tooth loss without much tooth structure removal to the young patients and the patients with gingival recession. We report these patients were satisfied with esthetic and function.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.91-97
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• 2014

In this paper, we propose weighted detection probability with distance between primary user and secondary users by using cooperative spectrum sensing based on energy detection. And we analysis and simulate the result. We suggest different distance between primary user and secondary users and the wireless channel between primary user and secondary users is modeled as Gaussian channel. From the simulation results of the cooperative spectrum sensing with weighted method make coverage bigger compared with non-weight, and We show higher sensing efficiency when we put weight detection probability than before method.