• 한국게임학회 논문지
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• 제7권2호
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• pp.21-32
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• 2007

물체 내부에서의 빛의 산란 현상 (subsurface scattering)에 기반한 조명 모델은 사실적인 이미지 생성에서 매우 중요하지만, 복잡한 계산으로 인하여 게임, 가상현실 등의 대화형 환경에 적용되기 어려웠다. 우리는 빛의 단일 산란과 다중 산란 현상에 의한 조명을 이미지 상에서 근사하는 보다 실용적인 기법을 제안한다. 먼저 광원 시점에서 렌더링한 이미지의 각 픽셀에 물체 내부로 투과된 조사도 정보를 저장하고, 쉐이딩 단계에서 이 정보를 사용하여 조명을 빠르게 계산한다. 단일 산란은 그림자 매핑과 유사한 알고리즘과 적응적인 결정적 샘플링을 통해 수행 비용을 효율적으로 줄인다. 다중 산란은 빛의 확산 이론에 기반한 계층적인 샘플링을 사용한다. 복잡한 함수의 테이블화은 속도를 보다 향상 시킨다. 실험을 통해 제안된 기법이 초당 수 십에서 수 백 프레임의 빠른 속도로 사실감있는 장면을 렌더링할 수 있으며, 게임과 같은 기존의 대화형 환경에 쉽게 적용될 수 있음을 보여준다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제29권1_2호
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• pp.91-97
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• 2002

본 논문에서는 자율수중운동체(AUVs, Autonomous Underwater Vehicles)의 실시간 충돌회피를 위한 휴리스틱 탐색기법을 논한다. 퍼지관계곱(fuzzy relational products)은 항행 환경에서 발생하는 장애물과 다음으로 이동 가능한 후보노드들과의 관계를 분석, 종합하는 수학적 도구로 사용된다. 본 논문은 영역전문가 보유한 장애물회피 관련 경험적 정보(heuristic information)를 반영하여 보다 효율적인 평가함수(evaluation function)를 고안하며 지능항행시스템의 상세경로설정(local path-planning)에 퍼지관계곱을 적용하여 보다 개선된 휴리스틱 탐색기법을 제안한다. 제안된 탐색기법의 성능검증을 위해 수행시간(cpu time), 경로의 최적화(optimization) 정도, 그리고 사용 메모리 관점에서 시뮬레이션을 통해 $A^{*}$ 탐색기법과 비교한다.

• Biomolecules & Therapeutics
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• 제25권2호
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• pp.140-148
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• 2017

Hyperlipidemia, which is closely associated with a fatty diet and aging, is commonly observed in the western and aged society. Therefore, a novel therapeutic approach for this disease is critical, and an immunological view has been suggested as a novel strategy, because hyperlipidemia is closely associated with inflammation and immune dysfunction. In this study, the effects of an aqueous extract of Rubus occidentalis (RO) in obese mice were investigated using immunological indexes. The mice were fed a high-fat diet (HFD) to induce hyperlipidemia, which was confirmed by biochemical analysis and examination of the mouse physiology. Two different doses of RO and rosuvastatin, a cholesterol synthesis inhibitor used as a control, were orally administered. Disturbances in immune cellularity as well as lymphocyte proliferation and cytokine production were significantly normalized by oral administration of RO, which also decreased the elevated serum tumor necrosis factor $(TNF)-{\alpha}$ level and total cholesterol. The specific immune-related actions of RO comprised considerable improvement in cytotoxic T cell killing functions and regulation of antibody production to within the normal range. The immunological evidence confirms the significant cholesterol-lowering effect of RO, suggesting its potential as a novel therapeutic agent for hyperlipidemia and associated immune decline.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.425-441
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• 2010

Forages are the backbone of sustainable agriculture. They includes a wide variety of plant species ranging from grasses, such as tall fescue and bermudagrass, to herbaceous legumes, such as alfalfa and white clover. Abiotic stresses, especially salinity, drought, temperature extremes, high photon irradiance, and levels of inorganic solutes, are the limiting factors in the growth and productivity of major cultivated forage crops. Given the great complexity of forage species and the associated difficulties encountered in traditional breeding methods, the potential from molecular breeding in improving forage crops has been recognized. Plant engineering strategies for abiotic stress tolerance largely rely on the gene expression for enzymes involved in pathways leading to the synthesis of functional and structural metabolites, proteins that confer stress tolerance, or proteins in signaling and regulatory pathways. Genetic engineering allows researchers to control timing, tissue-specificity, and expression level for optimal function of the introduced genes. Thus, the use of either a constitutive or stress-inducible promoter may be useful in certain cases. In this review, we summarize the recent progress made towards the development of transgenic forage plants with improved tolerance to abiotic stresses.

• 한국정보통신학회논문지
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• 제11권3호
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• pp.563-569
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• 2007

모바일 통신 서비스의 발전과 반도체 기술의 발달로 모바일 기기에 멀티미디어 서비스와 2D/3D 게임과 같이 고수준의 그래픽 처리를 필요로 하는 콘텐츠가 가능하게 되었다. 모바일 기기는 특성상 더욱 작은 칩 면적과 저전력 소비의 조건이 만족되어야 하며, 본 논문에서는 이러한 모바일 기기에 적용 가능한 2D/3D 벡터 그래픽 처리용 부동소수점 절사형 승산기를 설계한다. 본 논문의 승산기는 기본적으로 radix-4 Booth 인코딩을 적용하고, 면적과 전력소모를 줄이기 위하여 절사방식을 사용한다. 구현된 절사형 승산기는 평균 퍼센트 오차가 0.00003% 정도로 모바일 기기에 충분히 적용가능하다. 승산기는 0.35um CMOS 셀 라이브러리를 이용하여 논리 합성되었고, 그 결과 절사되지 않은 기존의 radix-4 Booth 승산기에 비해 게이트 수가 약 33.8%정도 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.160-169
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• 2022

In the present study we evaluated the efficacy of a bioformulation of Streptomyces cameroonensis for control of black pod disease in cocoa and enhancement of seedling growth. The formulation developed using talc powder and cassava starch as carriers showed high shelf-life of 1.07 × 10⁶ CFU/g after six months storage at 4℃. The formulation was tested for inhibition of spore germination in Phytophthora megakarya and showed 100% inhibition at 10% (w/v) of formulation. To determine the efficacy of the formulation, we performed an in planta assay in the greenhouse on two hybrids of cocoa seedlings, the tolerant SNK413 × (♂) T79/467 and the susceptible UPA 134× (♂) SCA 12. Detached leaf assay showed a significant reduction in the disease severity index of about 67% for the tolerant hybrid and 55% for the susceptible hybrid compared to non-treated plants. A significant enhancement in stem length, leaf surface area and root weight was observed. Analysis of biochemical markers of defense showed a significant increase in total polyphenol, flavonoid, and total protein contents. There was also significant upregulation of PR-proteins such as chitinases, peroxidases and β-1, 3-glucanases following treatment of both tolerant and susceptible hybrids, though with a higher level of synthesis in the tolerant hybrids. A significant increase was also observed in polyphenol oxidase activities in plants treated with the formulation. This work demonstrated the stability and effectiveness of the S. cameroonensis powder formulation in suppressing black pod disease in cocoa and subsequently enhancing the growth of seedlings.

• 생약학회지
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• 제53권2호
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• pp.70-78
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• 2022

The objective of this study was to assess the effect of preventing pigmentation caused by external stimuli, promoting skin regeneration and whitening of the skin composition containing complex extract of Dendrobii Caulis and Centella asiatica (CE). We evaluated cell viability, tyrosinase and melanin inhibition activity, skin irritation test, and skin moisturizing and regenerative effects using CE. As a result of the tyrosinase inhibitory activity, 100 ㎍/mL CE (35.31%) showed higher value than kojic acid (21.32%). The results of melanin synthesis inhibition in B16F10 melanoma cells after treatment with α-melanocyte stimulating hormone showed a similar level of activity to that of arbutin, indicating an excellent whitening effect. In clinical test of the skin composition containing CE, we confirmed that CE is non-irritated in human skin primary irritation test as well as have a high skin moisturizing and regenerative effect. From these results, we suggested the CE not only prevents skin damage and pigmentation caused by external stimuli but has remarkable skin brightening activity and skin regeneration effect.

• Molecules and Cells
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• 제46권6호
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• pp.351-359
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• 2023

Deamination of adenine or cytosine in RNA, called RNA editing, is a constitutively active and common modification. The primary role of RNA editing is tagging RNA right after its synthesis so that the endogenous RNA is recognized as self and distinguished from exogenous RNA, such as viral RNA. In addition to this primary function, the direct or indirect effects on gene expression can be utilized in cancer where a high level of RNA editing activity persists. This report identified actin-related protein 2/3 complex inhibitor (ARPIN) as a target of ADAR1 in breast cancer cells. Our comparative RNA sequencing analysis in MCF7 cells revealed that the expression of ARPIN was decreased upon ADAR1 depletion with altered editing on its 3'UTR. However, the expression changes of ARPIN were not dependent on 3'UTR editing but relied on three microRNAs acting on ARPIN. As a result, we found that the migration and invasion of cancer cells were profoundly increased by ADAR1 depletion, and this cellular phenotype was reversed by the exogenous ARPIN expression. Altogether, our data suggest that ADAR1 suppresses breast cancer cell mobility via the upregulation of ARPIN.

• ALGAE
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• 제39권1호
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• pp.17-30
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• 2024

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by Φ_PSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the F_v/F_m and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

• 생명과학회지
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• 제17권5호
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• pp.687-693
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• 2007

사람의 섬유아세포인 GM10을 사용하여 glucose의 배양조건에 다른 물질대사 및 IGFBP-3 발현을 살펴본 결과, glucose 농도에 따른 glucose 소비와 triglyceride 축적 수준은 고농도 glucose 배양 조건에서 증가한 반면, 총 단백질 함량은 고농도 glucose배양 조건에서 시간의 경과에 따라 감소하였다. 또한 고농도 glucose 배양 조건에서 5일 동안 배양한 세포 배양액내의 유리아미노산 함량은 저농도보다 고농도 glucose 배양 조건에서 높게 나타났다. IGFBP-3 단백질 수준과 mRNA수준은 저농도 glucose배양 조건에서 증가하였으나, IGFBP-3 단백질 분해효소에 따른 영향은 없었다. 이상의 결과에서 glucose 배양조건에 따른 물질대사는 부분적으로 세포를 이용한 당뇨병 모델 실험에서 in vivo와 같은 결과를 얻지 못하였지만, IGFs와 같은 세포 성장인자에 대한 연구를 통해 세포수준의 당뇨병 모델화가 가능하다고 여겨진다.