• 한국재료학회지
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• 제27권6호
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• pp.301-306
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• 2017

The discovery of new luminescent materials for use in light-emitting diodes(LEDs) has been of great interest, since LED-based solid state lighting applications are attracting a lot of attention in the energy saving and environmental fields. Recent research trends have centered on the discovery of new luminescent materials rather than on fine changes in well-known luminescent materials. In a sense, the novelty of our study beyond simple modification or improvement of existing phosphors. A good strategy for the discovery of new fluorescent materials is to introduce activators that are appropriate for conventional inorganic compounds, that have well-defined structures in the crystal structure database, but have not been considered as phosphor hosts. Another strategy is to discover new host compounds with structures that cannot be found in any existing databases. We have pursued these two strategies at the same time using composite search technology with particle swarm optimization(PSO). In this study, using PSO, we have tracked down a search space composed of Sr-Al-Si-O-N and have discovered a new phosphor structure with yellow luminescence; this material is a potential candidate for UV-LED applications.

• Genomics & Informatics
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• 제21권2호
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• pp.21.1-21.14
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• 2023

Fusobacterium nucleatum is a gram-negative bacteria associated with diverse infections like appendicitis and colorectal cancer. It mainly attacks the epithelial cells in the oral cavity and throat of the infected individual. It has a single circular genome of 2.7 Mb. Many proteins in F. nucleatum genome are listed as "Uncharacterized." Annotation of these proteins is crucial for obtaining new facts about the pathogen and deciphering the gene regulation, functions, and pathways along with discovery of novel target proteins. In the light of new genomic information, an armoury of bioinformatic tools were used for predicting the physicochemical parameters, domain and motif search, pattern search, and localization of the uncharacterized proteins. The programs such as receiver operating characteristics determine the efficacy of the databases that have been employed for prediction of different parameters at 83.6%. Functions were successfully assigned to 46 uncharacterized proteins which included enzymes, transporter proteins, membrane proteins, binding proteins, etc. Apart from the function prediction, the proteins were also subjected to string analysis to reveal the interacting partners. The annotated proteins were also put through homology-based structure prediction and modeling using Swiss PDB and Phyre2 servers. Two probable virulent factors were also identified which could be investigated further for potential drug-related studies. The assigning of functions to uncharacterized proteins has shown that some of these proteins are important for cell survival inside the host and can act as effective drug targets.

• 천문학회지
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• 제56권1호
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• pp.35-40
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• 2023

We have been conducting a exoplanet search survey using Bohyunsan Observatory Echelle Spectrograph (BOES) for the last 18 years. We present the detection of exoplanet candidate in orbit around HD 18438 from high-precision radial velocity (RV) mesurements. The target was already reported in 2018 (Bang et al. 2018). They conclude that the RV variations with a period of 719 days are likely to be caused by the pulsations because the Lomb-Scargle periodogram of HIPPARCOS photometric and H_α EW variations for HD 18438 show peaks with periods close to that of RV variations and there were no correlations between bisectors and RV measurements. However, the data were not sufficient to reach a firm conclusion. We obtained more RV data for four years. The longer time baseline yields a more accurate determination with a revised period of 803 ± 5 days and the planetary origin of RV variations with a minimum planetary companion mass of 21 ± 1 M_Jup. Our current estimate of the stellar parameters for HD 18438 makes it currently the largest star with a planetary companion.

• 한국응용곤충학회지
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• 제45권3호
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• pp.375-380
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• 2006

프루텔고치벌(Cotesia plutellae)은 단독형 내부기생봉으로 배추좀나방(Plutella xylostella)을 기주로 생활한다. 이 기생봉이 배추좀나방을 탐색하고 기주의 발육상태 및 다른 생리 상태를 인식하는데 촉각은 매우 중요한 감각기관으로 작용할 것으로 주목 받아왔다. 본 연구는 이 기생봉의 촉각 구조를 주사전자현미경으로 관찰하고, 관찰된 감각기 종류와 밀도를 바탕으로 기생생리를 이해하고자 수행되었다. 촉각 전체 길이에서 암수간 차이가 없으며 모두 16개 편절마디를 가지고 있다. 감각기 구조는 크게 긴털형감각기, 센털형감각기 그리고 판상감각기로 나누어 밀도조사를 실시하였고, 대부분 감각기는 편절에 집중적으로 분포했다. 이 가운데 긴털형감각기가 암수 모두 약 87%를 차지하였다. 편절에서 긴틸형감각기와 판상감각기는 말단 부위에서 밀도가 감소하는 반면, 센털형감각기는 말단 부위로 갈수록 증가하여, 암컷의 경우 9번째 편절 마디 이후로 급격하게 밀도 증가를 보였다. 촉각 부위별 제거에 따른 기생에 미치는 효과를 분석한 결과 편절 후반부를 제거하면 기생능력을 완전히 상실하고, 말단 4개 편절 마디를 제거해도 불과 30% 이하의 낮은 기생율을 기록했다. 이상의 결과는 프루텔고치벌의 기생에 촉각의 중요성을 보여주었으며, 특히 센털형감각기가 기주 탐색에 밀접히 관여될 가능성을 제시하였다.

• Child Studies in Asia-Pacific Contexts
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• 제6권1호
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• pp.17-29
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• 2016

To help define future research direction and enhance educational service for children from Asian and Latino immigrant backgrounds, this review examines research investigating social competence with reference to host and heritage language skills. A targeted search obtained 14 peer-reviewed studies published from 1994 to 2014 focusing on children aged from birth to 12 years. Social competence is mainly measured by four dimensions: externalizing behaviours, internalizing behaviours, social skills and relationships with others. The evidence suggests that English proficiency levels are positively associated with social skills and parent-child relationships are of higher quality when parent-child heritage language difference is minimal. However the findings are mixed regarding how English levels are associated with externalizing, internalizing behaviours and relationships with others and how heritage language levels are associated with social competence. This review makes a set of recommendations for future research including assessment of participants' language proficiency with language tests and examination of emotional factors in the relationship between English and social competence. The implications of the findings are also discussed for educators.

• Biomolecules & Therapeutics
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• 제11권1호
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• pp.1-4
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• 2003

Plants are known as important source in the search for new drugs. The twelve compounds from Viscum album (Loranthaceae), lupeol (1), betulonic acid (2), betulinic acid (3), terminic acid (4), ursolic acid (5), $\beta$-sitosterol (6), $\alpha$-spinasterol (7), oleanolic acid (8), 5-hydroxy-1-(4′-hydoxyphenyl)-7-(4"-hydroxyphenyl)-hepta-1-en-3-on (9), 2′-hydroxy-4′,6′-dimethoxychalcone-4-O-glucoside (10), 2′-hydroxy-4′,6′-dimethoxychalcone-4-O-[apiosyl(l$\longrightarrow$2)]glucoside (11) and syringin (12) were evaluated for their immunomodulatory properties. Compounds 6 and 11 induced the macrophage tumoricidal activity and the lymphocyte blastogenesis. In addition, these compounds stimulated the macrophages to induce the production of TNF-$\alpha$ and NO. These findings suggest that compounds 6 and 11 are modulating various elements of the host immune response.

• Journal of Ecology and Environment
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• 제33권2호
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• pp.115-120
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• 2010

The Asian cultural landscape is a mirrored ecosystem of great complexity, formed by the interaction of man and nature, coupled with a host of ecological processes. The human dependencies on and environmental adaptation of the bio-organisms and the surrounding landscape constitute the typical cultural landscape. Islands are a good example of a cultural landscape, and each mosaic pattern of marine and coastal ecosystems reflects bio-cultural diversity. Along with land-use patterns, wise use of biological organisms and indigenous knowledge has expanded to islands in the Asia-Pacific region in several ways (sea current and human impact, etc.). Loss in biodiversity and landscape diversity as well as cultural diversity owing to global warming and rapid urbanization are emerging issues for island ecosystems all over the world. In order to sustain the historical coexistence between man and natural systems, we ecologists must continue to search for a holistic solution for academic consilience. In this paper, I present the vision and practical characteristics of island ecology with a view toward the conservation of the traditional landscape and bio-cultural diversities in the seascape.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1279-1289
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• 2000

Recently, research activities for combining portable computer technology and wireless communication technology are in progress to realize mobile computing environment that designed to support mobile hosts in the existing network environments. For PCN environments, the location management strategies are particularly emphasized among various strategies necessary for the mobile computing environment. Location management strategy for PCN environment, which is mostly based on the IS-41 standards brings an issue that additional network traffics are generated to deliver updata messages to home location server whenever a mobile host changes its location server. In this paper, we propose an innovative updata strategy and a search strategy that resolves the problem shown in the IS-41 scheme for HLR/VLR structure of CDMA environments. Also, this paper presents the performance comparison of proposed scheme and scheme used in IS-41 obtained from a simulation. The simulation was conducted based on the number of messages, the rate of database accesses, and the number of hops visited when the location management scheme is executed.

• Bulletin of the Korean Chemical Society
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• 제17권9호
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• pp.814-819
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• 1996

In search of simple host molecules for uranyl ion which form 1: 1-type complexes with high formation constants that can be used either in extraction of uranium from seawater or in catalysis of biologically important organic reactions, the uranophile activities of dihydroxyazobenzene derivative 1 were studied. Uranyl ion and 1 form a 1: 1-type complex with a very large formation constant. The formation constant was measured at pH 7-11.6 by competition experiments with carbonate ion. From the resulting pH dependence, ionization constants of the two aquo ligands coordinated to the uranium of the uranyl complex of 1 were calculated. The ionization constants were also measured by potentiometric titration of the uranyl complex of 1. Based on these results, the pKa values of the two aquo ligands were estimated as 7.1 and 11.0, respectively. At pH 7.5-9.5, therefore, the complex exists mostly as monohydroxo species. Under the conditions of seawater, 1 possesses greater affinity toward uranyl ion compared with other uranophiles such as carbonate ion, calixarene derivatives, or a macrocyclic octacarboxylate. In addition, complexation of 1 with uranyl ion is much faster than that of the calixarene or octacarboxylate uranophiles.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2021년도 추계학술발표대회
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• pp.446-448
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• 2021

In training a deep learning model, it is crucial to tune various hyperparameters and gain speed and accuracy. While hyperparameters that mathematically induce convergence impact training speed, system parameters that affect host-to-device transfer are also crucial. Therefore, it is important to properly tune and select parameters that influence the data loader as a system parameter in overall time acceleration. We propose an automated framework called Num Worker Tuner (NWT) to address this problem. This method finds the appropriate number of multi-processing subprocesses through the search space and accelerates the learning through the number of subprocesses. Furthermore, this method allows memory efficiency and speed-up by tuning the system-dependent parameter, the number of multi-process spawns.