• Title/Summary/Keyword: 완전일치

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Detection of turbid water generated pipe through back tracing calculation method in water distribution system (상수관망에서 역추적 계산법을 이용한 탁수 발생관 탐지)

  • Kwon, Hyuk Jae;Kim, Hyeong Gi;Han, Jin Woo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.482-482
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    • 2023
  • 상수도관은 사용년수가 경과함에 따라 노후화가 진행되며, 노후화된 상수관은 내부적으로 부식, 이물질 퇴적, 균열 등의 현상이 발생하게 되고, 이는 결국 수질문제로 연결되어, 탁수사고 발생 확률증가의 주요 원인이 되고 있다. 국내 상수도관의 경우 매설년수의 증가로 인해 내구연한이 도래한 상수관망의 비중이 점차 증가하고 있으며, 2019년 서울시 문래동 수질사고, 2019년 인천 붉은 수돗물 사고, 2022년 안양 동안구 탁수사고, 2022년 여수시 웅천 탁수사고 등 관의 노후화로인한 탁수 사고가 빈번하게 발생되고 있어 수도 사용자에게 불편함을 끼치고 있다. 현재 정수장 및 상수관망에 설치된 탁도계를 통해 수질에 대한 감시를 진행하고 있지만, 경제적인 문제로 인해 모든 상수도관에 탁도계를 설치하기에는 현실적으로 불가능하며, 제한적인 탁도계의 개수를 통해 수질에 대한 감시 및 관리를 진행하고 있는 실정이다. 이러한 상황으로 인해 탁수사고 발생 시 발생 원인분석 및 최초 발생위치 결정이 쉽지 않으며, 보수 보강을 통한 상수도관의 정상화까지 오랜 시간이 걸리게 된다. 이에 본 연구에서는 상수관망에서 탁수 발생 시 최초 발생 위치를 결정할 수 있는 기법을 개발하였으며, 이를 실제 상수도관망에 적용하여 탁수발생 파이프를 탐지하였다. 탁수사고 발생 시 실측된 수질 데이터의 부족으로 인해 임의의 파이프에서 탁수가 발생하였다고 가상의 탁수 발생시나리오를 가정하였으며, 완전혼합농도식을 통해 관망에 설치된 탁도계의 NTU(Nethelometric Paultity Unit) 농도를 계산하여 가상의 탁수발생 시나리오를 상수도관망에 적용하였다. 이후, 역추적 계산기법을 통해 파이프의 초기 NTU 농도를 변화시켜주며 관망내 설치된 탁도계의 NTU 농도를 계산하였으며, 가상 시나리오를 적용하여 계산된 탁도계의 NTU 농도와 역추적 계산법을 적용하여 계산된 탁도계의 NTU 농도의 Percentage Error를 비교/분석하여 탁수 발생 파이프를 탐지하였다. 분석결과, 가상 시나리오의 최초 탁수발생 파이프와 역추적 계산법을 적용하여 탐지한 최초 탁수발생 파이프의 위치가 일치하는 것으로 나타났다. 본 연구에서 개발된 역추적계산을 통한 탁수발생 파이프 탐지기법을 실제 관로 교체사업에 활용한다면 파이프의 개선 우선순위를 보다 명확하게 판단할 수 있으며, 더 나아가 상수도 관망의 유지관리에 활용하여 경제적이고 효율적인 상수관망 시스템관리를 할 수 있을 것으로 판단된다.

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Postoperative Imaging of Rotator Cuff Tear (회전근개 파열의 수술 후 영상)

  • Min Hee Lee;Hee Jin Park;Ji Na Kim
    • Journal of the Korean Society of Radiology
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    • v.82 no.6
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    • pp.1388-1401
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    • 2021
  • Postoperative imaging of the rotator cuff may be performed routinely, even if pain or disability develops after surgery or if there are no symptoms. Postoperative images are obtained through MRI or US, and the purpose is to confirm the integrity of the restored tendon in general. Postoperative MRI has a relatively poor diagnostic accuracy compared to that of preoperative images because various materials used in surgeries deteriorate the image quality. US can dynamically check the condition of the restored tendon and avoid artifacts from the surgical instruments used for recovery. Although imaging findings are not always consistent with the clinical symptoms or prognosis, sub-deltoid fluid retention is more important for pain and functional recovery than the thickness of the reconstructed tendon. Strain elastography can also be a useful method for predicting the prognosis.

Phase Equilibria of the System Pd-Sb-Te and Its Geological Implications (팔라듐-안티몬-테루르 계(系)의 상평형(相平衡)과 지질학적(地質學的) 의의(意義))

  • Kim, Won-Sa;Chao, George Y.
    • Economic and Environmental Geology
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    • v.26 no.3
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    • pp.327-335
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    • 1993
  • Phase relations in the system Pd-Sb-Te were investigated at $1000^{\circ}$, $800^{\circ}$, and $600^{\circ}C$, using the sealed-capsule technique; the quenched products were studied by reflected light microscopy, X-ray diffraction, and electron microprobe analysis. At $1000^{\circ}C$, the solid phases Pd, $Pd_{20}Sb_7$, $Pd_8Sb_3$, $Pd_{31}Sb_{12}$, and $Pd_5Sb_2$ are stable with a liquid phase that occupies most of the isothermal diagram. Additional solid phases at $800^{\circ}C$ are $Pd_5Sb_3$, PdSb, $Pd_8Te_3$, $Pd_7Te_3$, and a continuous $Pd_{20}Te_7-Pd_{20}Sb_7$ solid solution becomes stable. At $600^{\circ}$, $PdSb_2$, $Pd_{17}Te_4$, $Pd_9Te_4$, PdTe, $PdTe_2$, $Sb_2Te_3$, and Sb and continuous PdSb-PdTe and $PdTe-PdTe_2$ solid solutions are stable. All the solid phases exhibit solid solution, mainly by substitution between Sb and Te to an extent that varies with temperature of formation. The maximum substitution (at.%) of Te for Sb in the Pd-Sb phases is: 44.3 in $Pd_8Sb_3$, 52.0 in $Pd_{31}Sb_{12}$, 46.2 in $Pd_5Sb_2$ at $800^{\circ}C$; 15.3 in $Pd_5Sb_3$, 68.3 in $PdSb_2$ at $600^{\circ}C$. The maximum substitution (at.%) of Sb for Te in the Pd-Te phases is 34.5 in $Pd_5Sb_3$ at $800^{\circ}C$, and 41.6 in $Pd_7Te_3$, 5.2 in $Pd_{17}T_4$, 12.4 in $Pd_9Te_4$, and 19.1 in $PdTe_2$ at $600^{\circ}C$. Physical properties and X-ray data of the synthetic $Pd_9Te_4$, PdTe, $PdTe_2$, $Pd_8Sb_3$, PdSb, and $Sb_2Te_3$ correspond very well with those of telluropalladinite, kotulskite, merenskyite, mertieite II, sudburyite, and tellurantimony, respectively. Because X-ray powder diffraction data consistently reveal a 310 peak ($2.035{\AA}$), the $PdSb_2$ phase is most probably of cubic structure with space group $P2_13$. The X-ray powder pattern of a phase with PdSbTe composition, synthesized at $600^{\circ}C$, compares well with that of testibipalladite. Therefore, testibiopalladite may be a member of the $PdSb_2-Pd(Sb_{0.32}Te_{0.68})$ solid solution series which is cubic and $P2_13$ in symmetry. Thus the ideal fonnula for testibiopalladite, presently PdSbTe, must be revised to PdTe(Sb, Te). Borovskite($pd_3SbTe_4$) has not been found in the synthetic system in the temperature range $1000^{\circ}-600^{\circ}C$.

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Clinical Characeristics of Intracordal Cysts (성대낭종의 임상적 특성)

  • Hong, Ki-Hwan;Park, Jung-Hoon;Kim, Won;Kim, Chang-Hyun
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.10 no.2
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    • pp.164-169
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    • 1999
  • Background and Objectives : The intracordal cysts are more increasingly diagnosed and treated due to advanced laryngeal stroboscopy and laryngeal microsurgical technique. The intracordal cysts are frequently misdiagnosed as vocal polyp or nodule The purpose of this study is to evaluate clinical features of intracordal cysts. Materials and Methods : In the present series, 83 cases of the intracordal cysts treated with laryngeal microsurgery are reported. The intracordal cysts are diagnosed preoperatively with indirect laryngoscopy, laryngeal endoscopy, laryngeal stroboscopy and confirmed with laryngeal microsurgical findings and biopsies. Results : Intracordal cysts are 83 of 1900 patients treated with laryngeal microsurgery(4.4%)-ductal cysts are 56 cases and epidermoid cysts are 27 cases. Intracordal cysts are more frequent in women, forties and the frequent site is an anterior third of the true vocal cord. With the indirect laryngoscopic examination, the ductal cysts are frequently misdiagnosed as vocal polyps or nodules but the epidermoid cysts are relatively easily diagnosed. The etiologic factors of the intracordal cysts are suspected as voice abuse and upper respiratory infection. The degree of postoperative voice satisfaction is similar to that of the vocal polyps. Conclusion : Intracordal cysts are frequently misdiagnosed as polyps or nodules, therefore preoperative stroboscopic findings and laryngeal microsurgical findings is important. An ideal treatment is to enucleate the cysts avoiding rupture of cyst and injury of lamina propria of the vocal cord.

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Reproducibility of Adenosine Tc-99m sestaMIBI SPECT for the Diagnosis of Coronary Artery Disease (관동맥질환의 진단을 위한 아데노신 Tc-99m sestaMIBI SPECT의 재현성)

  • Lee, Duk-Young;Bae, Jin-Ho;Lee, Sang-Woo;Chun, Kyung-Ah;Yoo, Jeong-Soo;Ahn, Byeong-Cheol;Ha, Jeoung-Hee;Chae, Shung-Chull;Lee, Kyu-Bo;Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.6
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    • pp.473-480
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    • 2005
  • Purpose: Adenosine myocardial perfusion SPECT has proven to be useful in the detection of coronary artery disease, in the follow up the success of various therapeutic regimens and in assessing the prognosis of coronary artery disease. The purpose of this study is to define the reproducibility of myocardial perfusion SPECT using adenosine stress testing between two consecutive Tc-99m sestaMIBI (MIBI) SPECT studies in the same subjects. Methods: Thirty patients suspected of coronary artery disease in stable condition underwent sequential Tc-99m MIBI SPECT studies using intravenous adenosine. Gamma camera, acquisition and processing protocols used for the two tests were identical and no invasive procedures were performed between two tests. Mean interval between two tests were 4.1 days (range: 2-11 days). The left ventricular wall was divided into na segments and the degree of myocardial tracer uptake was graded with four-point scoring system by visual analysis. Images were interpretated by two independent nuclear medicine physicians and consensus was taken for final decision, if segmental score was not agreeable. Results: Hemodynamic responses to adenosine were not different between two consecutive studies. There were no serious side effects to stop infusion of adenosine and side effects profile was not different. When myocardial uptake was divided into normal and abnormal uptake, 481 of 540 segments were concordant (agreement rate 89%, Kappa index 0.74). With four-grade storing system, exact agreement was 81.3% (439 of 540 segments, tau b=0.73). One and two-grade differences were observed in 97 segments (18%) and 4 segments (0.7%) respectively, but three-grade difference was not observed in any segment. Extent and severity scores were not different between two studios. The extent and severity scores of the perfusion defect revealed excellent positive correlation between two test (r value for percentage extent and severity score is 0.982 and 0.965, p<0.001) Conclusion: Hemodynamic responses and side effects profile were not different between two consecutive adenosine stress tests in the same subjects. Adenosine Tc-99m sestaMIBI SPECT is highly reproducible, and could be used to assess temporal changes in myocardial perfusion in individual patients.

A Study of a Non-commercial 3D Planning System, Plunc for Clinical Applicability (비 상업용 3차원 치료계획시스템인 Plunc의 임상적용 가능성에 대한 연구)

  • Cho, Byung-Chul;Oh, Do-Hoon;Bae, Hoon-Sik
    • Radiation Oncology Journal
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    • v.16 no.1
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    • pp.71-79
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    • 1998
  • Purpose : The objective of this study is to introduce our installation of a non-commercial 3D Planning system, Plunc and confirm it's clinical applicability in various treatment situations. Materials and Methods : We obtained source codes of Plunc, offered by University of North Carolina and installed them on a Pentium Pro 200MHz (128MB RAM, Millenium VGA) with Linux operating system. To examine accuracy of dose distributions calculated by Plunc, we input beam data of 6MV Photon of our linear accelerator(Siemens MXE 6740) including tissue-maximum ratio, scatter-maximum ratio, attenuation coefficients and shapes of wedge filters. After then, we compared values of dose distributions(Percent depth dose; PDD, dose profiles with and without wedge filters, oblique incident beam, and dose distributions under air-gap) calculated by Plunc with measured values. Results : Plunc operated in almost real time except spending about 10 seconds in full volume dose distribution and dose-volume histogram(DVH) on the PC described above. As compared with measurements for irradiations of 90-cm 550 and 10-cm depth isocenter, the PDD curves calculated by Plunc did not exceed $1\%$ of inaccuracies except buildup region. For dose profiles with and without wedge filter, the calculated ones are accurate within $2\%$ except low-dose region outside irradiations where Plunc showed $5\%$ of dose reduction. For the oblique incident beam, it showed a good agreement except low dose region below $30\%$ of isocenter dose. In the case of dose distribution under air-gap, there was $5\%$ errors of the central-axis dose. Conclusion : By comparing photon dose calculations using the Plunc with measurements, we confirmed that Plunc showed acceptable accuracies about $2-5\%$ in typical treatment situations which was comparable to commercial planning systems using correction-based a1gorithms. Plunc does not have a function for electron beam planning up to the present. However, it is possible to implement electron dose calculation modules or more accurate photon dose calculation into the Plunc system. Plunc is shown to be useful to clear many limitations of 2D planning systems in clinics where a commercial 3D planning system is not available.

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The Drawing of Linked-arc Designs in Bronze Mirrors and The Technological Genealogy of the Three-Hans Style Bronze Mirror (연호문(連弧文)의 제도와 삼한경(三韓鏡)의 기술 계보)

  • Yi, Yangsu
    • Korean Journal of Heritage: History & Science
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    • v.54 no.1
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    • pp.164-183
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    • 2021
  • This article examines how the production technology of the Chinese bronze mirror affected the Korean Peninsula and Japan. To that end, we looked at how the drawing of linked-arc designs in bronze mirrors was done. The drawing technique is classified into three methods: Type 1 and type 2 were confirmed to have been used in China, but type 3 was used not in China, but on the Korean Peninsula and in Japan. Type 1 and type 2 are basically the same, with an identical restored diameter of the linked-arc design, and type 2 is found elsewhere in the bronze mirror, and type 1 are not. Type 3 features different diameters, and the linked-arc design does not form a complete circle. This shows that the manufacturer of the bronze mirror did not use several bumpy compasses, but rather a single one with a fixed center and protrusion, rather than one that can be easily adjusted, as it is today. That is why, of course, a pair of compasses must have been used several times. In this regard, those who produced bronze mirrors on the Korean Peninsula in the early days understood not only the Chinese techniques of the linked-arc design, but also the meaning contained within them. On the other hand, the makers of bronze mirrors in Japan did not understand the patterns and simply imitated them. From the late Yayoi period, Japan understood and produced works with the principle of drawing the linked-arc design. As a representative example, bronze mirrors excavated from the tomb of Hirabaru can be referenced. Perhaps it can be assumed that, behind these works, there was a direct transfer of technology, such as the migration of the makers of bronze mirror makers like the Do family (陶氏), whose names were found written on bronze mirrors excavated from the Hirabaru tomb.

Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology (반응표면분석법을 이용한 전도성물질의 절연코팅 프로세스의 최적화)

  • Sim, Chol-Ho
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.44-51
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    • 2016
  • The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data ($Adj-R^2=0.944$). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was $530k{\Omega}{\cdot}cm$.

A Study on Information Efficiency in Stock Selection by Various Investor Type (투자자집단별 선택적 종목거래활동의 정보효율성 검증)

  • Lee, Sung-Hoon;Lee, Jung-Jin;Lee, Jae-Hyun
    • Management & Information Systems Review
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    • v.34 no.1
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    • pp.65-80
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    • 2015
  • In previous studies concerning turnover, they argue individual stock's turnover must be identical to market portfolio's turnover under one condition where 2 funds separation theorem holds. In this kind of world, all market participants hold and trade the same portfolio and this should be only market portfolio. If one's trading portfolio's shape is different from market portfolio's, this would mean he or she has an advantage over others in information and this kind of information would be private. In accordance with this theory, we develop a metric which measures how far one's trading portfolio from market's and name it as Stock Selection by Investor(SSI). We apply this measurement to the various types of investor groups classified as individual, institutional and foreign who participate in Korea stock market. To test the validity of measure, we regress price ratio on this measurement using SUR method. As a result, individual investor group shows large number in SSI, but the coefficient in regression is not significant and economically meaningless. In case of institutional investor group, the coefficient proves to be significantly negative. We can infer from this fact that their trading is somehow far from informed trading. Stock selection activity by foreign investor groups proves to be informed trading by showing significantly positive coefficient and the magnitude of coefficient is economically meaningful, especially in sell activity.

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The Effects of Fear of Failure Factors Affecting Entrepreneurial Intentions of Startup Business Candidate (예비창업자의 실패에 대한 두려움이 창업의도에 미치는 영향)

  • Kim, Soojin;Han, Jungwha;Lee, Sangmyung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.11 no.3
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    • pp.49-61
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    • 2016
  • This study investigates the relationship between fear of failure of potential entrepreneur's psychological characteristics and entrepreneurial intentions using the mediation variables of planned behavior model. There are many existing prior research related to the entrepreneurial intentions, but they were mostly focused only entrepreneurial success factors. So in this study we focused on fear of failure of potential entrepreneur. To know the influence of the fear of failure related to entrepreneurial intention, we using the scale of PFAI (Performances Failure Appraisal Inventory). The purpose of this study is to examine an impact of fear of failure on entrepreneurial intention and add to mediating factors - attitude toward the acts, subjective norm, perceived behavior control - on the relationship between fear of failure and entrepreneurial intention. Also we examined entrepreneurial education as moderating effect in order to offset the fear of failure. In order to test research model, we collected data from 321 undergraduate students. To test the research questions and hypotheses, we employed SPSS 21.0 anf AMOS 18.0 for validity, reliability, confirmatory factor analysis, and structural model analysis. The results were as follows. First, the fear of failure negatively related to attitude toward the behavior and subjective norm. Second, attitude toward the behavior and subjective norm positively related to entrepreneurial intention in consistent with previous studies. Third, attitude toward the acts and subjective norm in TPB variables have full-mediation effects between fear of failure and intrepreneurial intention. Fourth, The moderating effects of entrepreneurial effect was not significant. The negative relationship between fear of failure and attitude toward the acts and subjective norm was even slightly stronger who have taken the entrepreneurial class group. We discuss the theoretical and managerial implications, and provide suggestions for future research.

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