• 제목/요약/키워드: $k_0$ factor

검색결과 12,171건 처리시간 0.041초

Evaluation of multi-lane transverse reduction factor under random vehicle load

  • Yang, Xiaoyan;Gong, Jinxin;Xu, Bohan;Zhu, Jichao
    • Computers and Concrete
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    • 제19권6호
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    • pp.725-736
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    • 2017
  • This paper presents the two-, three-, and four-lane transverse reduction factor based on FEA method, probability theory, and the recently actual traffic flow data. A total of 72 composite girder bridges with various spans, number of lanes, loading mode, and bridge type are analyzed with time-varying static load FEA method by ANSYS, and the probability models of vehicle load effects at arbitrary-time point are developed. Based on these probability models, in accordance to the principle of the same exceeding probability, the multi-lane transverse reduction factor of these composite girder bridges and the relationship between the multi-lane transverse reduction factor and the span of bridge are determined. Finally, the multi-lane transverse reduction factor obtained is compared with those from AASHTO LRFD, BS5400, JTG D60 or Eurocode. The results show that the vehicle load effect at arbitrary-time point follows lognormal distribution. The two-, three-, and four-lane transverse reduction factors calculated by using FEA method and probability respectively range between 0.781 and 1.027, 0.616 and 0.795, 0.468 and 0.645. Furthermore, a correlation between the FEA and AASHTO LRFD, BS5400, JTG D60 or Eurocode transverse reduction factors is made for composite girder bridges. For the two-, three-, and four-lane bridge cases, the Eurocode code underestimated the FEA transverse reduction factors by 27%, 25% and 13%, respectively. This underestimation is more pronounced in short-span bridges. The AASHTO LRFD, BS5400 and JTG D60 codes overestimated the FEA transverse reduction factors. The FEA results highlight the importance of considering span length in determining the multi-lane transverse reduction factors when designing two-lane or more composite girder bridges. This paper will assist bridge engineers in quantifying the adjustment factors used in analyzing and designing multi-lane composite girder bridges.

농도실측 및 연료 성분조성에 의한 중소형 RPF 소각시설의 온실가스 배출계수 개발 (The Development of Emission Factors of Greenhouse Gas from Middle and Small-Scaled RPF Incineration Facility by Concentration Measurement and Fuel Composition)

  • 나경호;송일석;최시림;유재인;박익범;김진길
    • 한국대기환경학회지
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    • 제28권4호
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    • pp.423-434
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    • 2012
  • This study was carried out to develop for the emission factor of greenhouse gas (GHG) from medium and smallscaled incineration facility using RPF which is considering as a part of renewable energy in UNFCC. The actual concentration of the exhaust gas and the fuel composition of RPF were measured for the calculation of GHG emission factor in RPF incinerators, and were compared with the IPCC guideline. The $CO_2$ and $N_2O$ emission factors by the actual concentration of exhaust gas were $2.3575{\pm}1.0070tCO_2/tRPF$ and $0.0014{\pm}0.0014tN_2O/tRPF$ respectively. Also, $CO_2$ emission factor by the RPF composition was $2.7057{\pm}0.0540tCO_2/tRPF$. The GHG emission factor per energy by the actual concentration was $83.0867{\pm}26.0346tCO_2e/TJ$ which showed higher consistency with the GHG emission factor ($80.3967tCO_2e/TJ$) of waste plastic in the IPCC guideline (2006b). The $CO_2$ and $N_2O$ emission factor calculated in this study is considered as a meaningful data for GHG emission factor of RPF incineration facility because of not being developed in ROK.

수치 정밀토양에 기초한 전국 토양유실량의 평가를 위한 USLE/RUSLE 인자의 산정 (USLE/RUSLE Factors for National Scale Soil Loss Estimation Based on the Digital Detailed Soil Map)

  • 정강호;김원태;허승오;하상건;정필균;정영상
    • 한국토양비료학회지
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    • 제37권4호
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    • pp.199-206
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    • 2004
  • 국가 전체의 토양유실량을 산정하기 위하여 범용토양유실예측공식 (USLE)과 개정 범용토양유실예측공식(RUSLE)의 각 인자를 재평가하였다. 정 외 (198,B)과 박 외 (2000)의 연구결과를 거리역산가중치법으로 계산하여 전국 150개 시군의 강우유출인자 (R)를 평가하였고, 한국토양총설 (1992), Taxonomical Classification of Korean Soils (2000), 농업환경변동조사사업 보고서 (2003)에 수록되어 있는 정보를 이용하여 390개 토양통, 1321개 토양상에 대한 토양침식성인자 (K)를 산출하였다. 지형인자 (LS)는 1 25,000 토양도를 이용하여 경사도, 경사장, 토지이용에 따른 대표 값을 산정하였으며 식생피복인자 (C)와 침식조절인자 (P)는 지난 27년간 농업과학기술원 토양보전분야의 연구결과를 종합하여 정리하였다 강우유출인자는 시군에 따라 2322-6408 MJ mm $ha^{-1}$ $yr^{-1}$ $hr^{-1}$이었으며 전체평균은 4276 MJ mm ha $yr^{-1}$ $hr^{-1}$이었다. 우리나라의 평균 토양침식성인자는 0.027 MT $r^{-1}$ $MJ^{-1}$ $mm^{-1}$이었으며 강 상류 및 내륙에 위치한 충북. 경북, 강원 등에서 낮았고, 경기, 충남, 전남등에서 높았다 토지이용별로 보면 논이 0.034 MT hr $MJ^{-1}$ $mm^{-1}$로 가장 컸고 밭, 임지, 초지가 각각 0.026, 0.019, 0.020 MT hr $MJ^{-1}$ $mm^{-1}$이었다. 밭의 작물인자는 0.06-0.45였으며 초지는 0.003이었다. 침식조절인자는 토양보전농법에 따라 0.01-0.85로 평가되었다.

갑상선 질환에서 표피성장인자 수용체 발현 (The Expression of Epidermal Growth Factor Receptor in Thyroid Diseases)

  • 민병철;이용진;차성재;박용검;지경천;임현묵;박성일;박성준
    • 대한두경부종양학회지
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    • 제15권2호
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    • pp.156-161
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    • 1999
  • Objectives: The epidermal growth factor receptor(EGFR) family has been increasingly recognized as an important component in the control of normal cell proliferation and the pathogenesis of cancer. To confirm the usefulness of epidermal growth factor receptor as a tumor marker, we initiated this study. Materials and Methods: EGFR was measured by immunohistochemical staining using EGFR antibody. It was performed on section from paraffin blocks of 65 thyroid tissue including 33 paillary carcinoma, 11 follicular carcinoma, 11 nodular hyperplasia, 5 follicular adenoma and 5 normal thyroid tissue. We evaluated morphologic characteristic of various thyroid neoplasms, and the relationship between EGFR and other prognostic factors in papillary thyroid carcinomas. Results: The expression of EGFR was commonly found in neoplasms of thyroid, with trend for stronger staining in the more malignant tumor(p=0.000). Also the expression of EGFR in papillary thyroid cancer related to tumor characters including tumor size(p=0.042), extent(p=0.024) and prognostic features including AMES scores(p=0.019). The strong EGFR staining in papillary carcinoma was significantly associated with tumor recurrence(p=0.003). Conclusions: EGFR may have a role in the regulation of normal and neoplastic thyroid cell growth. EGFR status may help predict the clinical course of patients with malignant thyroid neoplasms. However, the study of more cases will be needed for significance of the information about the EGFR as an independent prognostic factor.

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불임증(不姙症) 환자(患者)의 통계적(統計的) 고찰(考察);서울대학교병원(大學校病院) 불임상담실(不姙相談室) 1872 예(例)의 분석(分析) (An Analysis of Infertility Patients)

  • 장윤석;이진용;문신용;김정구;최승헌;임용택
    • Clinical and Experimental Reproductive Medicine
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    • 제12권1호
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    • pp.47-70
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    • 1985
  • This study was presented of the 1,872 cases of infertile couples who visited and examined at the sterility clinic of Department of Obstetrics & Gynecology, Seoul National University Hospital from Sept., 1980 to Dec., 1983. Age, duration of infertility, past medical history, and other general factors were analyzed, and the factors responsible for infertility were classified and discussed. Mode of treatment, outcome of pregnancy, pregnancy rate responsible for each factor were also presented. The results were as follows: 1) The infertility was primary in 1,128, or 60.3% and secondary in 744, or 39.7%. 2) The age between 26 and 30 years of age comprised about one half of the total patients. 3) The duration of infertility between 1 and 4 years comprised about three quarters of the total patients, and the mean duration was 3.8 years. 4) The most common medical history in primary infertility was tuberculous disease, and that in secondary infertility was history of previous laparotomy. 5) About two thirds of antecedent pregnancies were abortion. 6) The major etiologic factor of infertility were male factor in 12.3%, tubal factor in 38.8%, ovulatory failure in 25.4%, uterine factor in 8.8%, cervical factor in 5.2%, peritoneal factor in 9.5%, and no demonstrable cause in 11.3%. 7) The types of male factor were azoospermia in 61.6%, oligospermia in 25.8%, low motility in 11.6%, and other abnormality in 1.0%. 8) The types of ovulatory failure were ovarian failure in 7.4%, hypothalamo-pituitary failure in 8.1 %, hypothalamo-pituitary dysfunction (including Polycystic ovarian syndrome) in 30.2%, and hyperprolactinemia in 22.4%. 9) The types of uterine factor were endometrial tuberculosis in 27.5%, uterine synechia in 33.8%, uterine anomaly in 19.7%, myoma and polyp in 9.1 %, and luteal phase defect in 9.9%. 10) The types of peritoneal factor were pelvic adhesion in 80.9% and endometriosis in 19.6%. 11) Surgeries were done in 408 patients, and they were salpingolysis, lysis of extraadnexal adhesion, salpingostomy, fimbrioplasty, ovarian wedge resection for polycystic ovarian disease, tubo-tubal anastomosis, and tubo-uterine implantation in orders. 12) 243 pregnancies were achieved during the infertility work-up, of which livebirth was 46.5%, ectopic pregnancy was 7.4%, spontaneous abortion was 7.8%, and on-going pregnancy or lost to follow-up was 36.2%. 13) Pregnancy rates in various factors were male factor in 18.7%, ovulatory factor in 31.7%, tubal factor in 24.2%, uterine factor in 34.6%, cervical factor in 19.0%, peritoneal factor in 29.0%, combined factors in 10.5%, and unexplained infertility in 37.1%. Pregnancy rate in whole patients was 25.2%.

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PZN 치환에 따른 적층 압전변압기용 PMN-PZT 세라믹의 압전 및 유전 특성 (Piezoelectric and dielectric properties of PMN-PZN ceramics for multilayer piezoelectric transformer with PZN substitution)

  • 이창배;류주현;백동수;임인호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.59-61
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    • 2005
  • In this paper, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, $Pb[(Mn_{1/3},Nb_{2/3})_{0.07}(Zn_{1/3}Nb_{2/3})_a(Zr_{0.48}Ti_{0.52})_{1-0.07-a}O_3]$ ceramics were manufactured with the variations of PZN from 2 to 14mol% and their dielectric and piezoelectric properties were investigated. Sintering temperature was varied from 910 to $1000^{\circ}C$. At 8mol% PZN substituted specimen sintered at $970^{\circ}C$, electromechanical coupling factor(kp), mechanical quality factor(Qm), dielectric constant and peizoelectric constant($d_{33}$) showed the optimal values of 0.536, 1803, 1551 and 328[pC/N), respectively, for multilayer piezoelectric transformer application.

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특급 호텔 레스토랑 서비스 제공자의 위생 관리 평가 (The Evaluation of Service Employees' Sanitary Management in Hotels)

  • 유양자;이정기;최영심
    • 한국식품조리과학회지
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    • 제22권5호통권95호
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    • pp.565-572
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    • 2006
  • The purpose of this study was to evaluate the sanitary management of hotel employees in Seoul. The results were summarized as follows : The total mean of sanitary management perception by factor was 3.91${\pm}$0.62, in which personal sanitation, property management, environment and facility factors were, in order, 3.99${\pm}$0.82, 3.91${\pm}$0.75, 3.90${\pm}$0.86 and 3.85${\pm}$0.82, respectively. This study showed that there was a significant difference in the perception of sanitary management among environment, facility and property management by age based on general characteristics. While there were no differences by hiring type, there was a significant difference among environment, facility and property management with personal sanitation factor according to the employee’s career path. There was also a significant difference between property management and personal sanitation factor according to hotel management style. In addition, a significant difference was observed among environment facility and property management with personal sanitation factor according to work place. In conclusion, it is imperative to continue educational programs for sanitary management by career, work place and management style in order to improve sanitary management of hotel employees’.

Cobalt 치환된 칩인덕터용 NiZnCu Ferrite의 자기적 특성 연구 (Effect of Cobalt Substitution on the Magnetic Properties of NiZnCu Ferrite for Multilayer Chip Inductors)

  • 안성용;김익섭;손수환;송소연;한진우;최강룡
    • 한국자기학회지
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    • 제20권5호
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    • pp.182-186
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    • 2010
  • Cobalt가 치환된 NiZnCu ferrite의 소결 및 자기적 성질에 미치는 영향에 대해 연구 하였다. 칩인덕터용 $Ni_{0.36-x}Co_xZn_{0.44}Cu_{0.22}Fe_{1.98}O_4(0{\leq}x{\leq}0.04)$를 고상반응법으로 제조하였다. 소결조제를 사용하지 않고 $880{\sim}920^{\circ}C$에서 공기중 2시간 열처리 하였으며 초투자율, 품질계수 Q, 밀도, 수축율, 포화자화, 및 보자력을 측정하였다. Cobalt가 치환된 NiZnCu ferrite는 품질계수 Q를 증가시켰으며 칩인덕터용으로 사용 가능함을 알 수 있었다. 품질계수 Q는 치환량이 x = 0.01까지 증가한 후 x = 0.01 이후로 급격히 감소하였다. Cobalt의 치환량이 증가함에 따라 초투자율 및 밀도값은 감소하였다. $900^{\circ}C$에서 소성된 $Ni_{0.35}Co_{0.01}Zn_{0.44}Cu_{0.22}Fe_{1.98}O_4$ 토로이달 core 샘플의 경우 1 MHz에서 측정 시 초투자율값은 130이었고 품질계수 Q값은 230으로 나타났다.

Iron Oxide가 (K0.5Na0.5)(Nb0.96Sb0.04)O3 세라믹스의 유전 및 압전특성에 미치는 영향 (Effect of Iron Oxide on the Dielectric and Piezoelectric Properties of (K0.5Na0.5)(Nb0.96Sb0.04)O3Ceramics)

  • 서병호;류주현
    • 한국전기전자재료학회논문지
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    • 제23권8호
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    • pp.617-621
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    • 2010
  • ($K_{0.5}Na_{0.5}$)($Nb_{0.96}Sb_{0.04}$)$O_3$+1.2 mol% $K_4CuNb_8O_{23}$ ceramics doped with iron oxide ($Fe_2O_3$) were prepared by a conventional mixed oxide method. And then, their piezoelectric and dielectric properties were investigated as a function of $Fe_2O_3$ addition. X-ray diffraction studies reveal that $Fe^{3+}$ diffuses into the NKN lattices to form a solid solution with a pure perovskite structure at room temperature. At the sintering temperature of $1,060^{\circ}C$, when 0.2 mol% $Fe_2O_3$ was doped, the piezoelectric constant ($d_{33}$), electromechanical coupling factor (Kp), and mechanical quality factor ($Q_m$) showed the excellent values of 131.67 pC/N, 0.436, and 696.36, respectively. Results show that $Fe_2O_3$ deped ($K_{0.5}Na_{0.5}$)($Nb_{0.96}Sb_{0.04}$)$O_3$+1.2 mol% $K_4CuNb_8O_{23}$ lead-free piezoelectric ceramics are a promising lead free material for piezoelectric transformer applications.

유아를 둔 주부들의 유기농 식품 구매 인식 및 결정요인 (Survey on Recognition and Purchase Decision Factors related to Organic Food in Housewives with Young Children)

  • 김병희;최근영;강근옥
    • 동아시아식생활학회지
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    • 제26권2호
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    • pp.152-162
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    • 2016
  • This study surveyed recognition and purchase decision factors related organic food in housewives with young children. The most common reason for purchasing was "environmental-friendly" with 47.6%. When checking food labels, "nutritional ingredients" was the most considered (29.5%). Preference levels for organic food were in the following order: grains (26.8%) > vegetables (23.7%) > dairy (16.9%) > root and tuber crops (14.0%) > fruits (6.0%). For awareness of quality of organic food, the highest awareness factor was "safer than normal food" at $3.91{\pm}0.72$. For awareness of confidence in organic food, the highest awareness factor was "good for health" at $4.11{\pm}0.68$. For awareness of satisfaction of organic food, the highest awareness factor was "origin labeling" at $4.02{\pm}0.76$. Regarding awareness of purchasing intention of organic food, the highest awareness factor was "I will purchase organic food as possible as I can" at $4.02{\pm}0.79$. In the correlation analysis, confidence and satisfaction displayed the highest correlation (0.640), and there were other significant correlations between value/purchasing intention (0.586), confidence/purchasing intention (0.560), and satisfaction/purchasing intention (0.575). Further, the analysis showed that among value, quality, and price, only value had direct influence on the purchasing intention.