• Title/Summary/Keyword: Loss occurred

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A Study for reduction of the power loss of PV modules (PV moudule의 출력손실 저감요인 분석)

  • Lee, Sang-Hun;Kang, Gi-Hwan;Yu, Gwon-Jong;Ahn, Hyung-Keun;Han, Deuk-Young
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.45-50
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    • 2011
  • The efficiency of solar cell was about 4[%] in initial stage of photovoltaic industry, but it has quite a lot of efficiency through technology advances. Today, the efficiency of c-Si solar cells is about 17 to 19[%] and the efficiency of PV modules is about 14 to 15 [%]. We called that electrical losses occurred in the Conversion of solar cells to PV modules are CTM loss(Cell To Module loss), the CTM loss typically has a value of about3~5[%]. The more efficiency of solar cell increase, differences are larger because the efficiency decrease owing to physical or technical problems occurred in the Conversion of solar cells to PV modules. In this study, the power loss factors occurred in the Conversion of solar cells to PV modules are analyzed and it is proposed that how to reduce losses of the PV module. The types of power loss factor are (1)losses of front glass and encapsulant(generally EVA sheet), (2)losses by sorting miss, (3)losses by interconnection, (4)losses by the field aging of PV modules. In further study, experimental and evaluation will be conducted to make demonstrate for proposed solutions.

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Impact of Aerobic Exercise and Acupuncture Treatment on Obese Patients; A Retrospective Case-Controlled Study

  • Sezgin, Yilmaz;Kaplan, Askin Keskin
    • Journal of Pharmacopuncture
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    • v.24 no.2
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    • pp.54-58
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    • 2021
  • Objectives: The purpose of this study is to investigate the effects of aerobic exercise and acupuncture treatment in obese patients. Methods: The effects of exercise in obese patients receiving acupuncture therapy were investigated in this retrospective, case-controlled study in which subjects complying with exercise were enrolled in the case and non-compliers were enrolled in the control group. Results: There was a statically significant weight loss in both the study case group (94.39 ± 20.36; 88.91 ± 19.00; n = 22; p = 0.001) and the control group (103.18 ± 21.92; 99.56 ± 21.92; n = 34; p = 0.001) after 3 months. Weight loss occurred in all 22 patients in the case group. In the control group, while weight loss occurred in 27 of the 34 patients, weight gain occurred in three patients. Conclusion: In conclusion, the addition of modalities such as acupuncture, exercise and diet may provide effective improvement in weight control.

Effect of Carbon Addition and Influence of Heat-treatment Temperature on Electromagnetic Wave Absorbing Properties of $Ni_{0.5}Cu_{0.1}Zn_{0.4}Fe_2O_4$-Rubber Composite ($Ni_{0.5}Cu_{0.1}Zn_{0.4}Fe_2O_4$ Ferrite-Rubber Composite의 전파흡수특성에 미치는 열처리 온도의 영향 및 Carbon 첨가효과)

  • 윤국태;이찬규;박연준
    • Journal of the Korean Magnetics Society
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    • v.11 no.1
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    • pp.14-20
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    • 2001
  • The structure, shape, size, and magnetic properties of Ni$_{0.5}$Cu$_{0.1}$Zn$_{0.4}$Fe$_2$O$_4$ have been investigated as a function of annealing temperatures. In order to control the microwave absorbing properties of ferrite-rubber composite and the complex losses (magnetic loss and conduction loss), the effect of carbon addition was also studied. It was found that the coercive force decreased with increasing heat-treatment temperatures. Relative complex permeability and reflection loss were measured by the network analyzer. As a result, the natural resonance occurred in the low frequency tinge, and the matching frequency of the ferrite-rubber composite prepared at 130$0^{\circ}C$ was found to be lower. As heat-treatment temperatures were increased, the magnetic loss ($\mu$$_{r}$", $\mu$$_{r}$′) and the dielectric loss ($\varepsilon$$_{r}$"/$\varepsilon$$_{r}$′) were increased. It was caused that the absorption characteristics of the absorber were improved. The conduction loss and magnetic loss were expected to be occurred together because two matching frequencies were shown with carbon addition. It was confirmed that the matching frequency of the microwave absorber could be controlled by controlling heat-treatment temperatures and carbon additions.ons.tions.

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Causual Analysis on Soil Loss of Safety Class Oryun Tunnel Area in Landslide Hazard Map (산사태 위험지도에서 안전등급지역인 오륜터널 일대의 토사유실 원인분석)

  • Kim, Tae Woo;Kang, In Joon;Choi, Hyun;Lee, Byung Gul
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.1
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    • pp.17-24
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    • 2016
  • At present, summer cloudburst and local torrential rainfalls have increased in this country, because of climatic change. Therefore, studies on prevention of soil loss have been actively proceeded, and Korea Forest Service has offered landslide hazard map. Landslide hazard map divides risks into 5 classes, by giving weight with 9 kinds of elements. In August 25 2014, soil loss occurred in the whole Oryun Tunnel, Geumjeong-gu, Busan, because of local torrential heavy rain. As a result of comparing with landslide hazard map, the area where soil loss occurred in reality is a safety zone on hazard map. Rainfall, soil map, geological map, forest type map, gradient, drainage network, watershed, basin shape, and efflux of the whole Oryun Tunnel where soil loss occurred were analyzed. As a result of an analysis, it is judged that soil, forest type, much efflux and peak discharge, degree of water network and basin shape of a place where landslide occurred are causes of soil loss. It is judged that efflux, peak discharge, and basin shape by the localized rainfall that is not considered in landslide hazard map of them are the biggest causes of soil loss. It is judged that efflux, peak discharge, degree of water network and basin shape by the rainfall are important through a study on a causual analysis on soil loss in the whole Oryun Tunnel where is one of occurrence area where a lot of propertywere lost by the record local torrential rainfalls. A localized torrential downpour should be prepared by considering these elements on judgement of a landslide hazard area.

Effect of Sodium Chloride on Weight Loss of AA1100 Aluminum Alloy and SGACD Zinc coated Steel Lap Joint

  • Maulidin, Achmad;Kimapong, Kittipong
    • International Journal of Advanced Culture Technology
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    • v.3 no.1
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    • pp.39-45
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    • 2015
  • This research aims to study an effect of sodium chloride solution concentration on the corrosion rate of AA1100 aluminium alloy and SGACD zinc coated steel lap joint with a test duration of 30 days and a test temperature of $45^{\circ}$. The summarized results are as follows. Increase of the NaCl solution concentration increased the weight loss of Al, corrosion rate of Al, weight loss of Fe and also decreased the corrosion rate of Fe. Increase of the test duration affected to increase the weight loss and corrosion rate of Al and also decrease the weight loss and corrosion rate of Fe. The corrosion that was formed in a lap joint consisted of the uniform corrosion on the surface of the metals and the galvanic corrosion in the lap area of the joint. The maximum weight loss of AA 1100 aluminium and SGACD zinc coated steel that was occurred in the sodium chloride with 3.25% was 2.203% and 3.208%, respectively.. The maximum corrosion rate of AA 1100 aluminium and SGACD zinc coated steel that was occurred in 4.00% and 3.5% sodium chloride solution was 0.156 mm/year and 0.479 mm/year, respectively.

Comparison about TCP and Snoop protocol on wired and wireless integrated network (유무선 혼합망에서 TCP와 Snoop 프로토콜 비교에 관한 연구)

  • Kim, Chang Hee
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.2
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    • pp.141-156
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    • 2009
  • As the TCP is the protocol designed for the wired network that packet loss probability is very low, because TCP transmitter takes it for granted that the packet loss by the wireless network characteristics is occurred by the network congestion and lowers the transmitter's transmission rate, the performance is degraded. The Snoop Protocol was designed for the wired network by putting the Snoop agent module on the BS(Base Station) that connect the wire network to the wireless network to complement the TCP problem. The Snoop agent cash the packets being transferred to the wireless terminal and recover the loss by resending locally for the error occurred in the wireless link. The Snoop agent blocks the unnecessary congestion control by preventing the dupack (duplicate acknowledgement)for the retransmitted packet from sending to the sender and hiding the loss in the wireless link from the sender. We evaluated the performance in the wired/wireless network and in various TCP versions using the TCP designed for the wired network and the Snoop designed for the wireless network and evaluated the performance of the wired/wireless hybrid network in the wireless link environment that the continuous packet loss occur.

SUPPRESSION OF HYDROGEN CONSUMING BACTERIA IN ANAEROBIC HYDROGEN FERMENTATION

  • Park, Woo-Shin;Jang, Nam-J.;Hyun, Seung-H.;Kim, In-S.
    • Environmental Engineering Research
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    • v.10 no.4
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    • pp.181-190
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    • 2005
  • Severe loss or hydrogen occurred in most anaerobic hydrogen fermentation reactors. Several selected methods were applied to suppress the consumption of hydrogen and increase the potential of production. As the first trial, pH shock was applied. The pH of reactor was dropped nearly to 3.0 by stopping alkalinity supply and on]y feeding glucose (5 g/L-d). As the pH was increase to $4.8{\pm}0.2,$ the degradation pathway was derived to solventogenesis resulting in disappearance of hydrogen in the headspace. In the aspect of bacterial community, methanogens weren't detected after 22 and 35 day, respectively. Even though, however, there was no methanogenic bacterium detected with fluorescence in-situ hybridization (FISH) method, hydrogen loss still occurred in the reactor showing a continuous increase of acetate when the pH was increased to $5.5{\pm}0.2$. This result was suggesting the possibility of the survival of spore fanning acetogenic bacteria enduring the severely acidic pH. As an alternative and additive method, nitrate was added in a batch experiment. It resulted in the increase of maximum hydrogen fraction from 29 (blank) to 61 % $(500\;mg\;NO_3/L)$. However, unfortunately, the loss of hydrogen occurred right after the depletion of nitrate by denitrification. In order to prevent the loss entangled with acetate formation, $CO_2$ scavenging in the headspace was applied to the hydrogen fermentation with heat-treated sludge since it was the primer of acetogenesis. As the $CO_2$ scavenging was applied, the maximum fraction of hydrogen was enhanced from 68 % to 87 %. And the loss of hydrogen could be protected effectively.

Evaluation of Cyst Loss in Standard Procedural Steps for Detecting of Giardia lamblia and Cryptosporidium parvum in Water

  • Kim, Kyung-Ju;Jung, Hyang-Hee;Lee, Ki-Say
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.4
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    • pp.368-371
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    • 2006
  • The standard procedure outlined by the United States Environmental Protection Agency (US EPA) in Method 1623 for analyzing Giardia lamblia cysts and Cryptosporidium parvum oocysts in water samples consists of filtration, elution, centrifugal concentration, immunomagnetic separation (IMS), and immunofluorescence assay (IFA) followed by microscopic examination. In this study, the extent of (oo)cyst loss in each step of this procedure was evaluated by comparing recovery yields in segmented analyses: (i) IMS + IFA, (ii) concentration + IMS + IFA, and (iii) filtration/elution + concentration + IMS + IFA. The complete (oo)cyst recovery by the full procedure was $52{\sim}57%$. The (oo) cyst loss in the IMS step was only $0{\sim}6%$, implying that IMS is a fairly reliable method for (oo)cyst purification. Centrifugal concentration of the eluted sample and pellet collection before IMS resulted in a loss of $8{\sim}14%$ of the (oo)cysts. The largest (oo)cyst loss occurred in the elution step, with $68{\sim}71%$ of the total loss. The permeated loss of (oo)cysts was negligible during filtration of the water sample with a $1.0-{\mu}m$ pore polyethersulfone (PES) capsule. These results demonstrated that the largest fraction of (oo)cyst loss in this procedure occurred due to poor elution from the filter matrix. Improvements in the elution methodology are therefore required to enhance the overall recovery yield and the reliability of the detection of these parasitic protozoa.

Clinical Experiences with the Scapular Fascial Free Flap

  • Park, Il Ho;Chung, Chul Hoon;Chang, Yong Joon;Kim, Jae Hyun
    • Archives of Plastic Surgery
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    • v.43 no.5
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    • pp.438-445
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    • 2016
  • Background The goal of reconstruction is to provide coverage of exposed vital structures with well-vascularized tissue for optimal restoration of form and function. Here, we present our clinical experience with the use of the scapular fascial free flap to correct facial asymmetry and to reconstruct soft tissue defects of the extremities. Methods We used a scapular fascial free flap in 12 cases for soft tissue coverage of the extremities or facial soft tissue augmentation. Results The flaps ranged in size from $3{\times}12$ to $13{\times}23$ cm. No cases of total loss of the flap occurred. Partial loss of the flap occurred in 1 patient, who was treated with a turnover flap using the adjacent scapular fascial flap and a skin graft. Partial loss of the skin graft occurred in 4 patients due to infection or hematoma beneath the graft, and these patients underwent another skin graft. Four cases of seroma at the donor site occurred, and these cases were treated with conservative management or capsulectomy and quilting sutures. Conclusions The scapular fascial free flap has many advantages, including a durable surface for restoration of form and contours, a large size with a constant pedicle, adequate surface for tendon gliding, and minimal donor-site scarring. We conclude that despite the occurrence of a small number of complications, the scapular fascial free flap should be considered to be a viable option for soft tissue coverage of the extremities and facial soft tissue augmentation.

A Study On Status of Remodeling in Newly Built Apartments and Its Improvements (신축 공동주택의 리모델링 실태와 개선방안에 관한 연구)

  • Kim, Jae-Yeob;Lee, Ji-Young;Kim, Dae-Won
    • Journal of the Korea Institute of Building Construction
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    • v.6 no.4 s.22
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    • pp.103-108
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    • 2006
  • Currently, due to remodeling of newly built apartment, national resource loss and personal economic loss are being occurred and construction wastes are making more environmental issues. This study aims to devise reduction in cost and economic loss coming from remodeling by selecting general house size of apartment, carrying out surveys and investigating current status of remodeling before and after moving into newly built apartments.