• Title/Summary/Keyword: 과대평가

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Evaluation of Methane Generation Rate Constant(k) by Estimating Greenhouse Gas Emission in Small Scale Landfill (소규모 매립지에 대한 메탄발생속도상수(k) 산출 및 온실가스 발생량 평가)

  • Lee, Wonjae;Kang, Byungwook;Cho, Byungyeol;Lee, Sangwoo;Yeon, Ikjun
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.5
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    • pp.5-11
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    • 2014
  • In this study, greenhouse gas emission for small scale landfill (H and Y landfill) was investigated to deduce special the methane generation rate constant(k). To achieve the purpose, the data of physical composition was collected and amount of LFG emission was calculated by using FOD method suggested in 2006 IPCC GL. Also, amount of LFG emission was directly measured in the active landfill sites. By comparing the results, the methane generation rate constant(k), which was used as input variable in FOD method suggested in 2006 IPCC GL, was deduced. From the results on the physical composition, it was shown that the ranges of DOC per year in H (1997~2011) and Y (1994~2011) landfill sites were 13.16 %~23.79 % ($16.52{\pm}3.84%$) and 7.24 %~34.67 % ($14.56{\pm}7.30%$), respectively. The DOC results showed the differences with the suggested values (= 18 %) in 2006 IPCC GL. The average values of methane generation rate constant(k) from each landfill site were $0.0413yr^{-1}$ and $0.0117yr^{-1}$. The results of methane generation rate constant(k) was shown big difference with 2006 IPCC GL defualt value (k = 0.09). It was confirmed that calculation results of greenhouse gas emission using default value in 2006 IPCC GL show excessive output.

Comparison of Actigraphic Performance between $ActiWatch^{(R)}$ and $SleepWatch^{(R)}$:Focused on Sleep Parameters Utilizing Nocturnal Polysomnography as the Standard (활동기록기($ActiWatch^{(R)}$$SleepWatch^{(R)}$) 성능 비교 연구:야간수면다원기록을 표준으로 한 수면변인을 중심으로)

  • Shin, Hong-Beom;Lee, Ju-Young;Lee, Yu-Jin;Kim, Kwang-Jin;Lee, Eun-Young;Han, Jong-Hee;Im, Mee-Hyang;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.12 no.1
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    • pp.27-31
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    • 2005
  • Objectives: We attempted to compare the performance of 2 commercially available actigraphies with focus on sleep parameters, using polysomnography as standard comparison tool. Methods: Fourteen normal volunteers (5 males and 9 females, mean age of $28{\pm}4.6\;years$) participated in this study. All the participants went through one night of polysomnography, simultaneously wearing 2 different kinds of actigraphies on each wrist. Polysomnographic and actigraphic data were stored, downloaded, and processed according to standard protocols and then statistically compared. Results: Both $ActiWatch^{(R)}$ and $SleepWatch^{(R)}$ tended to overestimate the total sleep time, compared to the polysomnography. $SleepWatch^{(R)}$ tended to underestimate the sleep latency. The two actigraphs and the polysomnograph did not show significant difference of sleep efficiency, when compared with one another. In addition, all of the sleep parameters from the instruments showed linear correlations except in $SleepWatch^{(R)}'s$ sleep latency. The sleep parameters from the two actigraphs did not show much noteworthy difference, and linear relationships were found between the sleep parameters from the two actigraphs. There was no significant distinction in the results of the two different actigraphs. Conclusion: The results of two actigraphies can be used interchangeably since the sleep parameters of the two different actigraphies do not show significant differences statistically. Overall, it is not legitimate to use actigraphy as a substitute for polysomnography. However, since sleep parameters except sleep latency show linear correlations, actigraphy might possibly be used to follow up patients after polysomnography.

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A Reliability Analysis of Shallow Foundations using a Single-Mode Performance Function (단일형 거동함수에 의한 얕은 기초의 신뢰도 해석 -임해퇴적층의 토성자료를 중심으로-)

  • 김용필;임병조
    • Geotechnical Engineering
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    • v.2 no.1
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    • pp.27-44
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    • 1986
  • The measured soil data are analyzed to the descriptive statistics and classified into the four models of uncorrelated-normal (UNNO), uncorrelated-nonnormal (VNNN), correlatedonnormal(CONN), and correlated-nonnormal(CONN) . This paper presents the comparisons of reliability index and check points using the advanced first-order second-moment method with respect to the four models as well as BASIC Program. A sin91e-mode Performance function is consisted of the basic design variables of bearing capacity and settlements on shallow foundations and input the above analyzed soil informations. The main conclusions obtained in this study are summarized as follows: 1. In the bearing capacity mode, cohesion and bearing-capacity factors by C-U test are accepted for normal and lognormal distribution, respectively, and negatively low correlated to each other. Since the reliability index of the CONN model is the lowest one of the four model, which could be recommended a reliability.based design, whereas the other model might overestimate the geotechnical conditions. 2. In the case of settlements mode, the virgin compression ratio and preccnsolidation pressure are fitted for normal and lognormal distribution, respectively. Constraining settlements to the lower ones computed by deterministic method, The CONN model is the lowest reliability of the four models.

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Analysis of Urban Heat Island (UHI) Alleviating Effect of Urban Parks and Green Space in Seoul Using Deep Neural Network (DNN) Model (심층신경망 모형을 이용한 서울시 도시공원 및 녹지공간의 열섬저감효과 분석)

  • Kim, Byeong-chan;Kang, Jae-woo;Park, Chan;Kim, Hyun-jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.4
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    • pp.19-28
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    • 2020
  • The Urban Heat Island (UHI) Effect has intensified due to urbanization and heat management at the urban level is treated as an important issue. Green space improvement projects and environmental policies are being implemented as a way to alleviate Urban Heat Islands. Several studies have been conducted to analyze the correlation between urban green areas and heat with linear regression models. However, linear regression models have limitations explaining the correlation between heat and the multitude of variables as heat is a result of a combination of non-linear factors. This study evaluated the Heat Island alleviating effects in Seoul during the summer by using a deep neural network model methodology, which has strengths in areas where it is difficult to analyze data with existing statistical analysis methods due to variable factors and a large amount of data. Wide-area data was acquired using Landsat 8. Seoul was divided into a grid (30m × 30m) and the heat island reduction variables were enter in each grid space to create a data structure that is needed for the construction of a deep neural network using ArcGIS 10.7 and Python3.7 with Keras. This deep neural network was used to analyze the correlation between land surface temperature and the variables. We confirmed that the deep neural network model has high explanatory accuracy. It was found that the cooling effect by NDVI was the greatest, and cooling effects due to the park size and green space proximity were also shown. Previous studies showed that the cooling effects related to park size was 2℃-3℃, and the proximity effect was found to lower the temperature 0.3℃-2.3℃. There is a possibility of overestimation of the results of previous studies. The results of this study can provide objective information for the justification and more effective formation of new urban green areas to alleviate the Urban Heat Island phenomenon in the future.

Electro chemical characteristics of $(MnX)O_2$ electrode prepared by thermal decomposition method (열분해법으로 제조된 $(MnX)O_2$ 전극의 전기화학적 특성)

  • Kim, Hyun-Sik;Lee, Hae-Yon;Huh, Jeoung-Sub;Kim, Jong-Ryung;Lee, Dong-Yoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.348-351
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    • 2003
  • 산소 과전압이 낮은 $MnO_2$를 촉매로 사용하여 반도체 산화물계의 산소선택성 전극을 제조하고 산화물 coating층의 미세구조와 전기화학적 특성을 분석하였다. Ti 기판에 열분해 법을 이용하여 $MnO_2$ 피막을 형성하였고, 또한 PVDF : $MnO_2$의 함량비를 1 : 1에서 1 : 40까지 정량적으로 변화시키고 DMF의 함량을 각각의 고정된 PVDF : $MnO_2$의 함량비에서 변화시켜 Pb전극에 1.5 mm/sec의 속도로 5회 dipping하여 $MnO_2$ 피막층을 형성 하였다. $450^{\circ}C$에서 1시간 열분해하여 약 $1\;{\mu}m$$MnO_2$ 피막층이 형성되었으나 Ti 기판과의 접착력이 약하여 피막자체에 대한 전기화학적 특성을 관찰할 수 없었다. PVDF : DMF = 4 : 96인 경우 pb 전극의 피막층이 얇기 때문에 박리현상이 일어났으며 이는 산화물 용제의 낮은 점도 때문인 것으로 판단된다. 또한 PVDF : DMF = 10 : 90의 경우는 5회 dipping 하여 약 $150\;{\mu}m$의 피막층을 형성하였다. PVDF : $MnO_2$의 함량비가 1:1에서 1:6 까지는 DMF의 함량에 무관하게 전극 특성이 나타나지 않았지만 $MnO_2$의 양이 상대적으로 증가하면 cycle이 증가하더라도 거의 일정한 전류 값을 갖고 $MnO_2$와 PVDF의 비가 20:1 이상의 조성에서는 균일한 CV 특성을 나타냈다. 이는 $MnO_2$가 효과적으로 촉매 작용을 한 것으로 판단되며 anodic polarization에 의한 산소 발생 과전압도 약 1.4V 정도로 감소되었다.동등한 MSIL 코드를 생성하도록 시스템을 컴파일러 기법을 이용하여 모듈별로 구성하였다.적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만들기, 일반화가 가능한 문제 등으로 보고, 수학적 창의성 중 특히 확산적 사고에 초점을 맞추어 개방형 문제가 확산적 사고의 요소인 유창성, 독창성, 유연성 등에 각각 어떤 영향을 미치는지 20주의 프로그램을 개발, 진행하여 그 효과를 검증하고자

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Surgical Results for Treating Postpneumonectomy Empyema with BPF by Using an Omental Pedicled Flap and Thoracoplasty (전폐절제술 후 기관지 흉막루를 동반한 농흉에서 유경성 대망 이식편과 흉곽성형술을 이용한 수술적 치료에 대한 임상 고찰)

  • Jeong, Seong-Cheol;Kim, Mi-Jung;Song, Chang-Min;Kim, Woo-Shik;Shin, Yong-Chul;Kim, Byung-Yul
    • Journal of Chest Surgery
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    • v.40 no.6 s.275
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    • pp.420-427
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    • 2007
  • Background: Postpneumonectomy empyema (PPE) due to bronchopleural fistula (BPF) can be a surgical challenge for surgeons. We analyzed the follow-up outcomes after performing omentopexy and thoracoplasty for the treatment of PPE with BPF after pneumonectomy. Material and Mehod: Between December 1991 and January 2006, 9 patients underwent BPF closure using an omental pedicled flap for the treatment of PPE with BPF after pneumonectomy. There were 7 males and 2 females (mean age: $45.9{\pm}9$ years). The patients were followed up for a mean of 58 months (median: 28 months, range: $6{\sim}169$). When we performed omentopexy, the surgical procedures for empyema were thoracoplasy for 8 patients and the Clagett procedure for 1 patient. Thoracoplasty was performed for the latter patient due to recurrence of empyema, Result: For the 8 patients who were treated by omentopexy and thoracoplasty, there was 1 operation-related death due to sepsis. During follow up, 1 patient, who was treated by omentopexy and a Clagett procedure, died of acute hepatitis 40 months postoperatively. The early mortality was 11.1% (8/9). Of the 8 patients, including the 1 late death patient, successful closure of the BPF were achieved in all patients (8/9) and the empyema was cured in 7 patients (7/8). Conclusion: The BPF closure using an omental pedicled flap was an effective method for treating PPE with BPF due to 75-destroyed lung, and thoracoplasty with simultaneous omentopexy was effective and safe for removing dead space if the patient was young and in a good general condition.

Validation of the physical activity classification table for Korean youth and assessment of total energy expenditure, estimated energy requirement and physical activity in Korean children and adolescents (한국 소아청소년을 위한 신체활동분류표의 타당도 평가 및 이를 이용한 일일 총에너지소비량, 에너지필요추정량과 신체활동 평가)

  • Ji-Yeon Gwak;Myung-Hee Kim;Jonghoon Park;Kazuko Ishikawa-Takata;Eun-Kyung Kim
    • Journal of Nutrition and Health
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    • v.56 no.1
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    • pp.35-53
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    • 2023
  • Purpose: The purpose of the first part of this study was to evaluate the validity of the physical activity classification table for youth (Youth-PACT). The second part of this study was aimed at comparing the estimated energy requirement (EER) with the total energy expenditure (TEE) and evaluating the physical activity patterns of Korean children and adolescents. Methods: The subjects of the first part of the study were 17 children aged 10 to 12 years, and their total energy expenditure (TEEDLW) was measured using the double labeled water (DLW) method. A total of 166 children and adolescents aged 6-18 years participated in the second part of this study. Their resting energy expenditure (REE) was measured using indirect calorimetry and the TEEYouth-PACT and physical activity level were calculated by applying the Youth-PACT to the physical activity diary prepared by the subjects. Results: In the first part of this study, there were no significant differences between the TEEDLW and the TEEYouth-PACT. The TEEYouth-PACT accurately predicted TEEDLW in 37.5% of the subjects. In the second part of the study, the rates at which EER accurately predicted TEE YouthPACT and overestimated TEE Youth-PACT were 29.6% and 47.3%, respectively. The time spent based on intensity of physical activity and the physical activity categories which were obtained using Youth-PACT showed different patterns according to sex and age group. Age showed significant positive correlations with REE, TEE, and the time spent in sedentary behavior, but age was significantly negatively correlated with REE/body weight, TEE/body weight, and the time spent in low-intensity and high-intensity activities. Conclusion: The results of this study showed that the Youth-PACT can be used to evaluate the TEE and PAL of children and adolescents. However, further studies are needed to validate the TEEYouth-PACT and to set the EER for children and adolescents.

Behavioral Mechanism of Hybrid Model of Soil-nailing and Compression Anchor (쏘일네일링과 앵커가 결합된 하이브리드 공법의 거동 메커니즘)

  • Seo, Hyung-Joon;Kim, Hyun-Rae;Jeong, Nam-Soo;Lee, In-Mo
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.117-133
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    • 2010
  • A hybrid system of soil-nailing and compression anchor is proposed in this paper; the system is composed of an anchor bar (installed at the tip) with two PC strands and a steel bar. After drilling a hole, installing proposed hybrid systems, and filling the hole with grouting material, prestress is applied to the anchor bar to restrict the deformation at the head and/or to prevent shallow slope failures. However, since the elongation rate of PC strand is much larger than that of steel bar, yield at the steel bar will occur much earlier than at the PC strand. It means that the yield load of the hybrid system will be overestimated if we simply add yield loads of the two - anchor bar and PC strands. It might be needed to try to match the yielding time of the two materials by applying the prestress to the anchor bar. It means that the main purpose of applying prestress to the anchor bar should be two-fold: to restrict the deformation at the nail head; and more importantly, to maximize the design load of the hybrid system by utilizing load transfer mechanism that transfers the prestress applied at the tip to the head through anchor bar. In order to study the load transfer mechanism in a systematic way, in-situ pullout tests were performed with the following conditions: soil-nailing only; hybrid system with the variation of prestress stresses from 0 kN to 196 kN. It was found that the prestress applied to the anchor system will induce the compressive stress to the steel bar; it will result in decrease in the slope of load-displacement curve of the steel bar. Then, the elongation at which the steel bar will reach yield stress might become similar to that of PC strands. By taking advantage of prestress to match elongations at yield, the pullout design load of the hybrid system can be increased up to twice that of the soil-nailing system.

Rumen Fermentation was Changed by Feed Inoculation Method in In Vitro (사료 접종 방법에 의한 in vitro 반추위 발효 상성 변화)

  • Yoo, Dae-Kyum;Moon, Joon-Beom;Kim, Han-Been;Yang, Sung-Jae;Park, Joong-Kook;Lee, Se-Young;Seo, Ja-Kyeom
    • ANNALS OF ANIMAL RESOURCE SCIENCES
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    • v.30 no.3
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    • pp.111-120
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    • 2019
  • The objective of this study was to investigate the effect of different feed inoculation method on rumen fermentation in an in vitro. Three experimental treatments were used: control (CON, direct dispersion of feed (2 g) in rumen fluid), combinations of direct dispersion (1 g) and nylon bag (DNB, pore size: 50 ㎛, 1 g), and nylon bag (NB, 2 g). An in vitro fermentation experiment was carried out using strained rumen fluid for 48 h incubation time and timothy was used as a substrate. At the end of the incubation, in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), pH, volatile fatty acids (VFA), ammonia nitrogen (NH3-N), and microbial community were evaluated and gas production was estimated at 3, 6, 12, 24, 48 h incubation periods. Gas production was higher in CON than DNB and NB at 6 and 12 h incubation time (p<0.01). There were no differences in final gas production, pH, NH3-N concentration, total VFA production, and VFA profiles among treatments. The IVDMD was lowest in CON (p<0.01) but the IVNDFD was not differed by feed distribution methods. There were no significant differences in general bacteria and fungi. Protozoa count was highest in NB treatment among treatments (p<0.01). The abundance of cellulolytic bacteria, Ruminococcus flavefaciens and Fibrobacter succinogenes, was highest in the CON among treatments (p<0.01).

A Study on the Method for Quantifying CO2 Contents in Decarbonated Slag Materials by Differential Thermal Gravimetric Analysis (DTG 분석법을 활용한 슬래그류 비탄산염 재료의 CO2 정량 측정방법 연구)

  • Jae-Won Choi;Byoung-Know You;Yong-Sik Chu;Min-Cheol Han
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.12 no.1
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    • pp.8-16
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    • 2024
  • Limestone (CaCO3, calcium carbonate), which is used as a raw material in the portland cement and steel industry, emits CO2 through decarbonation by high temperatures in the manufacturing process. To reduce CO2 emissions by the use of raw materials like limestone, it has been proposed to replace limestone with various industrial by-products that contain CaO but less or none of the carbonated minerals, that cause CO2 emissions. Loss of Ignition (LOI), Thermogravimetric analysis (TG), and Infrared Spectroscopy (IR) are used to quantitative the amount of CO2 emission by using these industrial by-products, but CO2 emissions can be either over or underestimated depending on the characteristics of by-product materials. In this study, we estimated CO2 contents by LOI, TG, IR and DTG(Differential Thermogravimetric analysis) of calcite(CaCO3) and samples that contain CO2 in the form of carbonate and whose weight increases by oxidation at high temperatures. The test results showed for CaCO3 samples, all test methods have a sufficient level of reliability. On the other hand, for the CO2 content of the sample whose weight increases at high temperature, LOI and TG did not properly estimate the CO2 content of the sample, and IR tended to overestimate compared to the predicted value, but the estimated result by DTG was close to the predicted valu e. From these resu lts, in the case of samples that contain less than a few percent of CO2 and whose weight increases during the temperature that carbonate minerals decompose, estimating the CO2 content using DTG is a more reasonable way than LOI, TG, and IR.