• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.69.2-69.2
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• 2010

Recently, bulk hetero-junction cells have been extensively studied by many researchers. Most of these cells were fabricated by spin coater. However, the spin coating process is not favorable to the large-scaled industry because it is not compatible with roll-to-roll process. One of the alternative methods is Doctor blading. In this study, we fabricated large OPV cells having total area of $100cm^2$. The buffer layer was Poly-(3,4-ethylenedioxythiophene) : poly-(styrenesulfonate) aqueous dispersion (PEDOT:PSS) and the active material is poly (3-hexythiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blend in the solvent of Chlorobenzene. All of the organic layers were coated by dragging the blade with a speed of 5~20 mm/s on the stage with a temperature of $50^{\circ}C$. As-bladed PEDOT:PSS layer was baked at $120^{\circ}C$ for 10 minutes to eliminate the water. The cell structure is patterned ITO substrate/PEDOT:PSS/P3HT:PCBM/LiF/Al. The topmost electrode, LiF/Al, was deposited by thermal evaporation. After depositing electrode, and the cell was annealed at $150^{\circ}C$ for 30 minutes. The measured ISC, VOC, fill factor, and PCE were 2.95 A, 5.86 V, 0.32, and 0.78%, respectively. PCE was quite low but the large active area could be obtained successfully.

• 한국환경보건학회지
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• 제38권6호
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• pp.568-574
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• 2012

Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.

• Journal of Power Electronics
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• 제16권3호
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• pp.1226-1235
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• 2016

For wearable health monitoring systems, a fundamental problem is the limited space for storing energy, which can be translated into a short operational life. In this paper, a highly efficient active voltage doubling rectifier with a wide input range for micro-piezoelectric energy harvesting systems is proposed. To obtain a higher output voltage, the Dickson charge pump topology is chosen in this design. By replacing the passive diodes with unbalanced-biased comparator-controlled active counterparts, the proposed rectifier minimizes the voltage losses along the conduction path and solves the reverse leakage problem caused by conventional comparator-controlled active diodes. To improve the rectifier input voltage sensitivity and decrease the minimum operational input voltage, two low power common-gate comparators are introduced in the proposed design. To keep the comparator from oscillating, a positive feedback loop formed by the capacitor C is added to it. Based on the SMIC 0.18-μm standard CMOS process, the proposed rectifier is simulated and implemented. The area of the whole chip is 0.91×0.97 mm², while the rectifier core occupies only 13% of this area. The measured results show that the proposed rectifier can operate properly with input amplitudes ranging from 0.2 to 1.0V and with frequencies ranging from 20 to 3000 Hz. The proposed rectifier can achieve a 92.5% power conversion efficiency (PCE) with input amplitudes equal to 0.6 V at 200 Hz. The voltage conversion efficiency (VCE) is around 93% for input amplitudes greater than 0.3 V and load resistances larger than 20kΩ.

• 공학논문집
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• 제4권1호
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• pp.93-107
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• 2002

본 연구에서는 정수장에서 사용후 폐기된 활성탄을 전자파로 조사 capillary 복원 능력을 조사하였고 활성화제의 종류 및 량에 따른 비표면적 변화에 대하여 연구하였다. 수증기를 활성화제로 사용한 경우에는 재생의 능력은 우수하나, 폐활성탄에 함유하고 있는 수분과 반응하여 자동이송에 문제점이 있는 것으로 나타났다. 또한 $CO_2$ gas로 재생한 결과 이송의 문제점도 해결되고 비표면적도 신탄에 비해 10-20%향상된 것으로 나타났다. 전자파의 세기에 있어서는 2.75kw 공급시 제일 좋은 재생효과가 나타났다. 각 변수에 의한 실험 후 반응물을 ASAP, SEM등을 이용하여 분석한 결과 전자파의 세기와 활성화제 종류 및 양에 따라 복원 능력이 다르게 나타났다. 특히 공기를 활성화제로 사용한 경우에는 복원능력의 오차가 심하게 나타났다. 이는 전자파에 의해 활성탄이 가열된 상태에서 공기의 량이 과다하게 투입, 산화, 연소되어 수율이 떨어지는 것으로 확인되었다. Microwave를 이용하여 폐활성탄을 재생시킨 결과 일반적으로 사용하고 있는 rotary kiln보다 우수한 재생효과가 나타났고, 경제성에서도 앞서는 것으로 나타났으나 대량 생산이 어렵다는 것이 단점으로 나타났다.

• 문화기술의 융합
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• 제7권1호
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• pp.564-569
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• 2021

본 연구에서는 일반적인 구조의 LED와 경사진 구조의 LED에 대하여, 전극이 없을 때와 전극에서 20%의 흡수(80% 반사)가 발생할 때, 그리고 전극에서 60%의 흡수(40% 반사)가 발생할 때로 구분하여, 전극에서의 흡수와 활성 영역의 높이가 광추출 효율 및 평균 광자 진행 거리에 미치는 영향을 조사하고, 활성 영역의 적절한 높이를 제안하였다. 일반적인 LED에서 전극의 흡수가 증가할수록, 광추출 효율은 18%에서 15%, 13%로 낮아지고, 활성 영역의 높이가 두 전극 사이의 정 중앙에 위치할 때 가장 광 추출 효율이 높다. 경사진 구조의 LED에서는 전극의 흡수가 증가할수록, 광추출 효율은 38%에서 33%, 25%로 낮아지고, 활성 영역의 높이가 두 전극 사이의 정 중앙에 위치할 때 가장 광 추출 효율이 높다. 경사진 구조의 LED는 일반적인 LED 보다 광추출 효율을 두 배 이상 높일 수 있다. 이는 전반사에 의해 광자가 칩 내부에 갇히는 현상을 줄여주기 때문이다.

• 한국실내디자인학회논문집
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• 제23호
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• pp.19-25
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• 2000

This study aims by analysing the interior design elements trends of current medium size office buildings in Seoul. The analysing objects are ceiling, floor, wall, and illumination plan of current office buildings. Analysing tools are finishing material and color of each part. Analysing areas are lobby area, deskwork area, conference area, welfare area, public area(rest room, corridor, stair). The interior design elements of lobby shows a lots of different features then the other areas in ceiling, floor, and wall design. Such difference appears at finishing material especially, and the coloring is more splendorous then the other areas. Desk work area and conference area have similar characteristics in finishing materiors and colors, and they usually follow the needs of function. Walfare area shows more splendorous feature then deskwork and conference area, and designed by various materials and colors. Public area also shows very active design concept then past times.

• 전기학회논문지
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• 제60권12호
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• pp.2368-2373
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• 2011

Traffic noise annoyance in dwelling area like private houses and apartment is becoming very important issue nowadays in South Korea. In this paper frequency analysis of the traffic noise was performed. Based on sound pressure levels analyses and its frequency content specific requirements for component of active noise control systems are formulated. Active compensational loudspeaker, microphone front end and DSP design were analysed, considered and proposed. Components specifications and design solutions are verified using modelling and experimental technique.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.371-372
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• 2005

Active sampler has been widely used to measure nicotine concentration in air. The experiments were conducted to compare the active sampler method with diffusive sampler in exposure chamber and smoking areas, respectively. The result of these tests that indicated that passive sampler can be used instead of active sampler in ETS, because coefficient of determination was 0.9292 between active and passive sampling in smoking area

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.45-49
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• 2013

Spherical active carbon materials have been used for the removal of pollutants in the area of food processing, water treatment, air purification, oral administration. Moreover, they are now expected to make an epoch in the areas of electronics, life science, environmental technology, and so on due to their superior physical properties. Carbon particles should be requested for the edgeless spherical shapes in order to minimize the loss due to the abrasion during the process and/or practical use, but the carbon particles manufactured from petroleum-based pitch do not meet these needs. Nowadays, thus, the spherical active carbon particles carbonized from various spherical polymer beads are studied with thermoplastic and/or thermosetting polymers. In this paper, the synthesis of spherical phenolic beads and furan beads, which are thermosetting polymers, and their carbonization techniques are examined.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2528-2530
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• 2005

In this paper, a study on the analysis and design of an electro-hydraulic pressure reducing valve for active suspension system of car is fulfilled. Also, the structurally improved direct-acting electro-hydraulic pressure reducing valve is proposed to satisfy the performance that active suspension system requires. To prove the possibility whether the proposed valve can be used for active suspension system or not, the mathematical modeling and analysis for this valve is fulfilled and the experiment of response to controlled pressure is achieved. Here we conformed the response speed to controlled pressure of the structurally improved valve changed for the better by modifying the shape of spool such as the structure which make use of the power of controlled pressure derived from the area difference between two section areas of valve spool.