• 한국광학회지
• /
• 제14권6호
• /
• pp.674-679
• /
• 2003

본 연구에서는 C-밴드와 L-밴드 파장(1525 nm-1625 nm)에서 파장 변화가 가능한 광섬유 링 레이저를 제작하고, 이를 이용하여 아세틸렌 분자 전이선에 대한 분광연구를 수행하였다. 제작된 광섬유 링 레이저는 공진기 내부에 FFP-TF(Fiber Fabry-Perot Tunable Filter)를 이용하여 약 102 nm(1510.4-1612.6 nm)의 범위에서 파장을 연속 가변할 수 있었다. 광섬유 링 레이저의 파장가변특성을 이용하여 C-밴드(1525-1565 nm)에서 흡수선이 많은 아세틸렌($^{13}$C$_2$H$_2$)분자에서 50개 이상의 전이선에 대하여 높은 신호대 잡음비를 갖는 흡수 스펙트럼을 측정하였다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2011년도 전력전자학술대회
• /
• pp.48-49
• /
• 2011

A new LCL filter design of a PCS with the consideration of fault current minimization is proposed. The magnitude of fault current is analysed with the variation of inverter side $L_i$, line side $L_u$, and filter capacitor $C_f$ under constant line side $THD_i$ of 5%. It is found that inverter side fault current reaches up to 200%~660% of the rated current with the variation of $L_i$. It is expected that the results can be applied to the detailed design of PCS filter.

• 한국수산과학회지
• /
• 제52권3호
• /
• pp.256-267
• /
• 2019

Styrofoam beads, which are relatively inexpensive and can provide a large specific surface area, were tested as filter media. Styrofoam beads with a diameter of $3{\pm}0.5mm$ were used; the specific surface area of the beads was $1,034m^2{\cdot}m^{-3}$. Five independent recirculating culture systems were used in the experiment. Each system consisted of one culture tank and three trickling bio-filters. Using the systems, nitrification efficiency was evaluated with respect to hydraulic loading rate (HLR) and carbon/nitrogen (C/N) ratio. The lowest ammonia and nitrogen concentrations were $0.84mg{\cdot}L^{-1}$ and $1.30mg{\cdot}L^{-1}$, respectively, observed at an HLR of $50.9m^3{\cdot}m^{-2}{\cdot}h^{-1}$. Nitrification efficiency in the culture tank was highest at a C/N ratio of 0, with ammonia and nitrite nitrogen concentrations of $0.32mg{\cdot}L^{-1}$ and $0.90mg{\cdot}L^{-1}$, respectively. Ammonia and nitrite nitrogen concentrations in the culture tank abruptly changed at C/N ratios ${\geq}3$.

• 한국물환경학회지
• /
• 제22권2호
• /
• pp.222-229
• /
• 2006

The treatment performance and operational parameters of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. In Filter 2, denitrification was accomplished under LV of 50~168 m/d in a 1 m filter-bed. However, the denitrification capacity reached the maximum when the linear velocity was increased to 202 m/d. Relationship between increase in microorganism and headloss was clearer in Filter 2. As a result, the denitrification rate increased from 1.0~2.3 kgN/($m^3-filter-bed{\cdot}d$) as the headloss increased. The COD removal rate was 6.0~9.6 kgCOD/($m^3-filter-bed{\cdot}d$) when operated with Filters 1 and 2. These results mean that captured bacteria contributed a part of COD consumption and denitrification. The maximum nitrification and denitrification rate was 0.5 and 4 kgN/($m^3-filter-bed{\cdot}d$) in Filter 1 and 2.The ratio of backwashing water to the treated water was about 5~10 %. In Filter 1, wasted sludge in backwashing was only 0.7~5.3 gSS/($m^3$-treated water). In Filter 2, added methanol was converted into sludge and its value was 8.0~24 gSS/($m^3$-treated water). These results proved that this process is both convenient to install as tertiary treatment and cost effective to build and operate.

• 한국환경보건학회지
• /
• 제30권5호
• /
• pp.410-416
• /
• 2004

The objective of this investigation was to evaluate applicability of precoat filtration that can be substituted for rapid sand filter of conventional water treatment system(CWTS). Precoat filter used in this experiment are candle filter. Element disk of candle are pore size $10{\mu}m(R),\;20{\mu}m(B)$ And diatomaceous earth are cake pore size $3.5{\mu}m$(Standard Super- Cel; A), $7{\mu}m$(Hyflo Super-Cel; B) and $17{\mu}m$(Celite 545RV; C). $2kg/m^2$ diatomaceous earth is used for precoating, it coated candle in $5{\sim}6mm$ thickness. 1. Al adsorption dosages by diatomaceous earth used in experimental we Hyflo Super-Cel 0.843mg/g, Standard Super-Cel 0.782 mg/g and Celite 545RV 0.766 mg/g. 2. Filtrate of precoat filter during 60min are R-C combination 20.7($m^3/m^2$)>B-C 18.3($m^3/m^2$)>B-B 15.0($m^3/m^2$)> R-B 12.9($m^3/m^2$)> R-A 11,093($l/m^2$). 3. Water quality of precoat filter effluent are thus. $KMnO_4$ consumption are $1.10{\sim}2.20mg/l$, removal rate are $30.9{\sim}65.6\%$. They are R-A 1.10(mg/l)(removal rate $65.6\%$). R-C(2.20 mg/l)(removal rate $30.9\%$). 4. $Al^{3+}$ are not detected with all combination, removal rate $100\%$. 5. Considering water quality and flux, continued running time of R-A combination is 7 hr. Accumulated filtrate are $74.4 m^3/m^2$, average flux is $177.2 l/m^2{\cdot}min$. And filtrate per diatomaceous earth 1g are 37.2 l. 6. R-A effluent's water quality are $KMnO_4$ Consumption 1.10(mg/l), DOC 1.161 mg/1, Al 0.0 mg/1, $UV_{254}$ 0.016/cm, Turbidity 0.1(NTU). R-A combination is suitable to precoat filtration for the settling basin effluent treatment.

• 한국물환경학회지
• /
• 제22권2호
• /
• pp.230-237
• /
• 2006

The operational parameters and control strategies of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. Methanol addition was controlled based on the COD/N ratio or McCarty's equation. Constant COD/N ratio control results in excess addition under large diurnal fluctuation of $NOx^--N$, and McCarty's equation can be used to add appropriate amount of methanol. Control of methanol addition by on-line nitrate measurement, control of aeration by on-line DO measurement, and control of backwashing by head loss measurement are successfully operated. These results proved that this process prove the easy-maintenance and cost-effectively treatment is attainable.

• 대한환경공학회지
• /
• 제31권7호
• /
• pp.467-472
• /
• 2009

Seedling 성장 실험은 나노입자에 대한 독성 평가로 사용되어 왔다. 본 연구에서는 오이에 대한 나노 아연과 나노 산화아연의 독성을 filter paper방법과 phytagel방법을 통해 평가해 보았다. 비교 결과 phytagel방법이 불용성인 나노아연, 산화 아연의 침전을 방지했다. 오이 seedling 길이는 노출된 나노 아연, 나노 산화 아연의 농도에 따라 filter 방법에서 음의 관계를 나타냈다. 나노 아연과 나노 산화 아연에 대한 오이의 EC50값은 598, 600 mg/L로 나타났다. Filter paper방법에서만 아연의 오이 내 생체 축적량은 노출된 나노 아연, 나노 산화 아연의 농도에 따라 증가하였다. 관찰 결과 filter paper방법이 phytagel 방법보다 더 좋은 protocol로 나타났다

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.2340-2344
• /
• 2003

This paper considers a tracking filter algorithm which can track a maneuvering target. Multiresolutional Interacting Multiple Model (MRIMM) algorithm is proposed to reduce computational burden. In this paper multiresolutional state space model equation and multiresolutional measurement equation are derived by using wavelet transform. This paper shows the outline of MRIMM algorithm. Simulation results show that MRIMM algorithm maintains a good tracking performance and reduces computational burden.

• 전기학회논문지
• /
• 제57권10호
• /
• pp.1861-1868
• /
• 2008

In this paper, Passive Telemerty RF Sensor System using Unscented Kalman Filter algorithm(UKF) is proposed. General Passive Telemerty RF Sensor System means that it should be "wireless", "implantable" and "batterless". Conventional Passive Telemerty RF Sensor System adopts Integrated Circuit type, but there are defects like complexity of structure and limit of large power consumption in some cases. In order to overcome these kinds of faults, Passive Telemetry RF Sensor System based on inductive coupling principle is proposed in this paper. Because passive components R, L, C have stray parameters in the range of high frequency such as about 200[KHz] used in this paper, Passive Telemetry RF Sensor System considering stray parameters has to be derived for accurate model identification. Proposed Passive Telemetry RF Sensor System is simple because it consists of R, L and C and measures the change of environment like pressure and humidity in the type of capacitive value. This system adopted UKF algorithm for estimation of this capacitive parameter included in nonlinear system like Passive Telemetry RF Sensor System. For the purpose of obtaining learning data pairs for UKF Algorithm, Phase Difference Detector and Amplitude Detector are proposed respectively which make it possible to get amplitude and phase between input and output voltage. Finally, it is verified that capacitive parameter of proposed Passive Telemetry RF Sensor System using UKF algorithm can be estimated in noisy environment efficiently.

• 한국연초학회지
• /
• 제24권1호
• /
• pp.46-52
• /
• 2002

This study was carried out to investigate the transfer rate of I-menthol constituent into cigarette case and delivery rate to cigarette smoke. Test sample was used a light-type standard brand cigarette made in Korea. I-Menthol contents was measured according to A.O.A.C(1990) method by G.C and smoking conditions was a puff volume of 35$m\ell$ and 2.0s duration, taken once per minute to filter tipping paper plus 3mmwith 20 cigarettes. Migration rate of menthol into cigarette case had an interrelation with triacetin contents into filter and 6% triacetin level was most suitable. I-Menthol transferred to filter part from tobacco sheet by 20.2% in one month after cigarette manufacture, and the transfer was continued subsequently. Maximum menthol transfer in five months was 4.1% to foils and other packing materials and the loss outside of cigarette pack was also 3.9% below. The migration balance of menthol into cigarette pack and the delivery to cigarette smoke were the optimum condition when menthol was added at the ration of 30% in filter to 70% in the other parts into cigarette.