• 전기전자학회논문지
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• 제19권1호
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• pp.10-17
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• 2015

본 논문에서는 3-Line buffers를 사용하여 Sobel 윤곽선 추출 블록을 FPGA로 효율적으로 설계하여 구현하고자 한다. FPGA는 영상처리 알고리즘 중 하나인 Sobel 윤곽선 추출 알고리즘을 처리하기에 적절한 환경을 제공한다. 윤곽선 추출을 위한 방법으로는 파이프라인 방법을 사용하였다. Sobel 윤곽선 연산에서 윤곽선 강도 레벨을 결정하기 위하여 유한 상태 기계로 구현 된 마스크 연산을 이용한 모델을 제안한다. 효율적인 LUT 및 플리플롭의 사용으로 시스템의 성능이 향상됨을 입증하였다. 제안하는 3-line buffers을 이용한 Sobel 추출 연산은 Xilinx 14.2으로 합성하고 Virtex II xc2vp-30-7-FF896 FPGA device으로 구현하였다. Matlab을 이용하여 제안된 3-Line buffers 설계 시 PSNR 성능이 향상됨을 확인하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.199-205
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• 1999

Vibrio vulnificus cytolysin caused platelet cytolysis and increased intracellular calcium concentration $([Ca^{2+}]_i)$ of rat platelets in a concentration-dependent manner. In the presence of V. vulnificus cytolysin (3 HU/ml), lactate dehydrogenase (LDH) activity was increased from $1.3{\pm}0.4%$ of control to $64.3{\pm}3.4%$ in platelet suspension buffer. In $Ca^{2+}-free$ platelet suspension buffer, however, V. vulnificus cytolysin did not induce $[Ca^{2+}]_i$ increase and LDH release. Addition of EGTA (2 mM) to suspension buffer after the initial $Ca^{2+}$ influx reversed $[Ca^{2+}]_i$ to the control level. However, a $Ca^{2+}$ channel blocker verapamil $(20\;{\mu}M)$ or mefenamic acid $(20\;{\mu}M)$ did not inhibit V. vulnificus cytolysin-induced $[Ca^{2+}]_i$ increase and LDH release. Divalent cations such as $Co^{2+},\;Cd^{2+}\;or\;Mn^{2+}$ (2 mM each) also did not alter V. vulnificus cytolysin-induced $[Ca^{2+}]_i$ increase and LDH release. V. vulnificus cytolysin (3 HU/ml)-induced calcium influx was completely blocked by lanthanum (2 mM). Lanthanum (2 mM) also completely blocked V. vulnificus cytolysin (3 HU/ml)-induced LDH release. Osmotic protectants such as, raffinose, sucrose or PEG600 (50 mM each) did not inhibit the lytic activity of V. vulnificus cytolysin. In conclusion, lanthanum sensitive $Ca^{2+}$ influx plays a significant role in Vibrio vulnificus cytolysin-induced platelet cytolysis and thrombocytopenia in V. vulnificus infection.

• 한국컴퓨터정보학회논문지
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• 제15권3호
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• pp.1-10
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• 2010

프로세서 플랫폼이 무선의 모바일 시스템으로 변화하면서 내장형 모바일 프로세서들의 성능은 계속적으로 향상 되었으며 기능은 보다 더 강력해 지고 있다. 무선의 휴대용 장비들은 유선 장비에 비해 휴대용 전원에 의한 제한된 전력을 공급받기 때문에, 이러한 시스템들에 대한 효율적 에너지 관리 기술의 중요성은 점차 증가하고 있다. 한편, 메모리 시스템은 프로세서 관점에서 시스템 전체의 성능을저하 시키는 주된 요소 가운데 하나이다. 비록 휴대용 전원의 효과적 활용을 위한 DVFS 기법과 관련된 많은 연구들이 존재하지만, 프로세서와 메모리 사이의 상호 관계에 대한 최근의 연구는 부족한 실정이다. 본 연구에서는 무선의 모바일 장치들에서 활용되는 내장형 응용 프로그램의 장단기 메모리 접근 특성을 반영하기 위한 새로운 DVFS 레벨 예측 알고리즘을 소개한다. 모의 실험 결과 본 논문에서 제시하는 DVFS 정책은 메모리 접근이 많은 벤치마크 프로그램의 경우 5.86%의 소비 에너지 감소 효과를 보여주고 있으며, 평균적으로는 3.60%의 소비 에너지 감소 효과를 보여주고 있다.

• Journal of Pharmaceutical Investigation
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• 제34권6호
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• pp.491-497
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• 2004

We investigated some important factors which affect the transdermal flux of ketoprofen, a nonsteroidal anti-inflammatory agent, as a first step to provide some basic knowledge for the development of a iontophoretic transdermal patch system. Factors such as current density, polarity, buffer (HEPES) and electrolyte concentration and pH were studied using hairless mouse skin. The effect of poly(L-lysin), which is known to affect the electro-osmotic flow through skin, on flux was also studied. Passive flux was about $20\;{\mu}g/cm^2hr$ at pH 4.0, but was negligible at pH 7.4 where all ketoprofen molecules dissolved are ionized (ketoprofen pKa=5.94). At pH 4.0, application of anodal current increased the flux further above the passive level, however anodal flux at pH 7.4 was much smaller than passive flux at pH 4.0. The application of cathodal current at pH 4.0 increased the average flux to $30-40\;{\mu}g/cm^2hr$, depending on the current density applied. At pH 7.4, cathodal flux was only about $5\;{\mu}g/cm^2hr$. Decrease in buffer and electrolyte concentration increased this cathodal flux about 10 fold. However decrease in HEPES buffer concentration 100 fold did not affect the flux. Anodal flux of acetaminophen was much larger than cathodal flux, indicating that electroosmotic flow can be playing an important role in the flux. Poly(L-lysin) increased the cathodal flux at pH 7.4. These results provide some important insights into the mechanism of transdermal flux of ketoprofen and the role of electroosmotic flow.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.72-81
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• 2019

Objective: To determine the effect of gut pH and rumen microbial fermentation on glycerol encapsulated in alginate and alginate-chitosan polymers. Methods: Glycerol was encapsulated at 2.5%, 5%, 7.5%, or 10% (w/w) with sodium alginate (A) and alginate-chitosan (AC) polymers. Surface morphology and chemical modifications of the beads were evaluated using scanning electron microscopy and Fourier transform infrared (FTIR) spectra. Encapsulation efficiency was determined at the 5% glycerol inclusion level in two experiments. In experiment 1, 0.5 g of alginate-glycerol (AG) and alginate-chitosan glycerol (ACG) beads were incubated for 2 h at $39^{\circ}C$ in pH 2 buffer followed by 24 h in pH 8 buffer to simulate gastric and intestinal conditions, respectively. In experiment 2, 0.5 g of AG and ACG beads were incubated in pH 6 buffer at $39^{\circ}C$ for 8 h to simulate rumen conditions. All incubations were replicated four times. Free glycerol content was determined using a spectrophotometer and used to assess loading capacity and encapsulation efficiency. An in vitro experiment with mixed cultures of rumen microbes was conducted to determine effect of encapsulation on microbial fermentation. Data were analyzed according to a complete block design using the MIXED procedure of SAS (SAS Institute, Cary, NC, USA). Results: For AG and ACG, loading capacity and efficiency were 64.7%, 74.7%, 70.3%, and 78.1%, respectively. Based on the FTIR spectra and scanning electron microscopy, ACG treatment demonstrated more intense and stronger ionic bonds. At pH 6, 36.1% and 29.7% of glycerol was released from AG and ACG, respectively. At pH 2 minimal glycerol was released but pH 8 resulted in 95.7% and 93.9% of glycerol released from AG and ACG, respectively. In vitro microbial data show reduced (p<0.05) fermentation of encapsulated glycerol after 24 h of incubation. Conclusion: The AC polymer provided greater protection in acidic pH with a gradual release of intact glycerol when exposed to an alkaline pH.

• 터널과지하공간
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• 제34권4호
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• pp.249-266
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• 2024

벤토나이트 완충재는 공학적방벽재 중 하나로 고준위방사성폐기물의 안전한 처분을 위해 매우 중요한 기능을 수행한다. 특정 지하수 조건에 의해 벤토나이트에 침식 혹은 파이핑 현상이 발생할 수 있으며, 이는 공학적방벽의 전반적인 안전성에 영향을 미친다. 이와 관련된 국내 선행 연구는 모두 실험실 규모에서 수행되었기 때문에, 그 결과의 유용함에도 불구하고 일정 부분 한계를 지닌다. 따라서 한국원자력연구원은 BEPT(Bentonite Erosion and Piping Test)를 계획하여 현장 조건으로의 확장 및 실증 연구를 수행할 계획이다. 자세한 실험 설계에 앞서, 처분 관련 기술 선도국에서 수행된 선행 연구를 수집하여 분석하였다. 적합 실험 부지, 시스템 설계 등을 분석하여 BEPT 상세 설계 시 반영하였다. 본 기술보고는 조사한 해외 사례와 함께 현재 진행 중인 BEPT 실험 현황을 소개하기 위해 작성되었다.

• KIEAE Journal
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• 제15권2호
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• pp.61-67
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• 2015

Purpose: The balcony in the apartment is important space not only as a fire escape but also as a buffer for heat and sound insulation. However, with the legalization of balcony expansion for residential apartments in Korea in 2006, many households have eliminated the balcony space altogether to increase the inner space, often without sufficient consideration for the effects on the indoor environment. This study examined the sound insulation performance of exterior-facing windows in enclosed balconies and the changes in the indoor acoustic environment due to expansion to provide a basis for appropriate balcony expansion. The apartments for the field test were chosen where two balcony types can be compared, and the sound insulation performance for the eighteen balcony windows was measured. The windows installed were typical double window with thickness 16 mm or 22 mm. Measurements of the weighted standard sound pressure level difference showed a decrease of about 3 dB in sound insulation performance due to expansion. For common exterior noise levels of 70-85 dB(A), the indoor noise level can exceed 45 dB(A), the limit level regulated in Korea. However, it was found that the sound insulation performance of the window and the quality of the construction have more influence on indoor noise levels than balcony expansion itself.

• 한국환경복원기술학회지
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• 제10권5호
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• pp.1-9
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• 2007

Local government with abundant natural resources should consider the nature conservation oriented planning process for the sustainable development. With this regard, the aim of this study is to provide a substantial methodology to support the decision-making process to designate the conservation areas. The objectives of the proposed methodology is to conserve natural resources in the local government's territory through quantitatively assessing the values of the natural resources based on various ecological factors such as topography, flora and fauna. In order to test the usability of the method, Gangneung City in Kangwon-Do is selected considering the latest data availability. Based on the assessment process land use of the subjected city could be categorized into 4 levels of conservative area, conservative level 1 area, conservative level 2 area, and conservative level 3 area. Among them, conservative area and conservative level 1 area could be combined as natural resources conservation area and the others could be regarded as buffer and transitional area. Especially conservation area is surrounded by conservation level 2 area. Conclusively, the GIS methods adopted in this could be the efficient illustrative tool to assess the local natural resource values with the central government established nature-environmental information systems.

• 한국사회복지학
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• 제46권
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• pp.319-348
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• 2001

The primary purpose of this study is to examine the buffering effect of social welfare services on the relationship between the level of older persons' impairment and burden experienced by the family caregivers. It also assessed the level of caregiving burden as well as the effect of both older person's impairment and the characteristics of the caregivers on burden. The survey data collected from 150 community residing family caregivers was used for analyses. Findings are as follows. First, the caregivers are more burdened in the deterioration of mental health, scarce time for oneself, and the suffering of social life than in other areas of burden. Second, the more severe the physical and the mental impairment of the elder, the more burden the caregivers experience. The caregivers' characteristics such as the worse mental health, the lower level of attachment to the elder, the longer caregiving hours are also related to the higher level of caregiving burden. Third, the caregivers' use of adult day care and respite care services buffer the relationship between the level of impairment of older persons and the caregiving burden. However, social work counselling, visiting nurse, homemaker services do not have such buffering effects. Among informal support, instrumental support buffers the relationship between the elder's physical impairment and burden, while emotional support buffers the relationship between the elder's mental impairment and burden. According to the results, implication for social welfare services and practice methods for the family caregivers was discussed.

• 방사성폐기물학회지
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• 제20권4호
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• pp.469-488
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• 2022

Technology for high-level-waste disposal employing a multibarrier concept using engineered and natural barrier in stable bedrock at 300-1,000 m depth is being commercialized as a safe, long-term isolation method for high-level waste, including spent nuclear fuel. Managing heat generated from waste is important for improving disposal efficiency; thus, research on efficient heat management is required. In this study, thermal management methods to maximize disposal efficiency in terms of the disposal area required were developed. They efficiently use the land in an environment, such as Korea, where the land area is small and the amount of waste is large. The thermal effects of engineered barriers and natural barriers in a high-level waste disposal repository were analyzed. The research status of thermal management for the main bedrocks of the repository, such as crystalline, clay, salt, and other rocks, were reviewed. Based on a characteristics analysis of various heat management approaches, the spent nuclear fuel cooling time, buffer bentonite thermal conductivity, and disposal container size were chosen as efficient heat management methods applicable in Korea. For each method, thermal analyses of the disposal repository were performed. Based on the results, the disposal efficiency was evaluated preliminarily. Necessary future research is suggested.