• Title/Summary/Keyword: indeterminate

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An Analytical Study for the Stair Joints Constructed with Prefabricated Form System (선시공 조립식 거푸집 공법을 이용한 계단 접합부의 접합방식에 따른 해석적 연구)

  • Lee, Eun-Jin;Jin, Byung-Chang;Chang, Kug-Kwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.301-304
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    • 2008
  • The stair joints constructed with prefabricated system are general method doing structure design at hinge. If you regarded joints to come in contact with a flight of stairs and a slope of stairs as hinge, the moment performance of joints is not in the least moment, so as the bending moment of the stair case is increased, the reinforcement increase. Also the use is decreased because increasing the joint damage of the vibration & fatigue load. No less the reason constructed with pin the stair joints because the construction efficiency of field work is useable. Recently, they are considering the construction efficiency, while the semi-rigid detail for bending performance of joints is proposed, but for now they don't reflect the detail. Therefore, we proposed that reflecting the method at design semi-rigid joints. We compared the moment performance with the stair joints designed at the rigid joints, semi-rigid joints and pin joints. The nonlinear behavior of staircase core statically indeterminate structure. The result of research is that a bending stiffness modulus bring to reflect the semi-rigid performance, the performance of the semi-rigid joint is better than pin joints, and that is judged the system better seismic and vibration performance because have excellent ductility more than rigid joint.

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Direct Inelastic Strut-Tie Model Using Secant Stiffness (할선강성을 이용한 직접 비탄성 스트럿-타이 모델)

  • Park Hong-Gun;Kim Yun-Gon;Eom Tae-Sung
    • Journal of the Korea Concrete Institute
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    • v.17 no.2 s.86
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    • pp.201-212
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    • 2005
  • A new strut-tie model using secant stiffness, Direct Inelastic Strut-Tie Model, was developed. Since basically the proposed design method uses linear analysis, it is convenient and stable in numerical analysis. At the same time, the proposed design method can accurately estimate the inelastic strength and ductility demands of struts and ties because it can analyzes the inelastic behavior of structure using iterative calculations for secant stiffness. In the present study, the procedure of the proposed design method was established, and a computer program incorporating the proposed method was developed. Design examples using the proposed method were presented, and its advantages were highlighted by the comparison with the traditional strut-tie model. The Direct Inelastic Strut-Tie Model, as an integrated analysis/design method, can directly address the design strategy intended by the engineer to prevent development of macro-cracks and brittle failure of struts. Since the proposed model can analyze the inelastic deformation, indeterminate strut-tie model can be used. Also, since the proposed model controls the local deformations of struts and ties, it can be used as a performance-based design method for various design criteria.

The Predictors and Clinical Impact of Positive Resection Margins on Frozen Section in Gastric Cancer Surgery

  • Kim, Se-Yeong;Hwang, Yoon-Sun;Sohn, Tae-Sung;Oh, Seung-Jong;Choi, Min-Gew;Noh, Jae-Hyung;Bae, Jae-Moon;Kim, Sung
    • Journal of Gastric Cancer
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    • v.12 no.2
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    • pp.113-119
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    • 2012
  • Purpose: The aim of this study is to compare the characteristics of tumor and prognosis, depending on the status of resection margin involvement, on the frozen section diagnosis in gastric cancer. Materials and Methods: This study was conducted retrospectively, in 83 margin-positive patients on the frozen section diagnosis, who underwent gastrectomy from July 1995 to September 2006. The control group was selected by matching the age, gender, TNM stage and status of adjuvant chemoradiotherapy, among those who had shown clear resection margins. The characteristics of tumor and patient survival are investigated, and they were analyzed between the two groups. Results: The tumor size was significantly larger in the study group than that of the control group (P=0.037). There was significant difference between the two groups in location of the tumors (P=0.003). Multivariate analysis indicated that only the location and Lauren's classification are independent factors, which affected the resection margin involvement. Median survival was $41.0{\pm}11.5$ months in the study group and $93.0{\pm}30.3$ months in the control group (P=0.049). In the survival analysis, it was investigated that TNM stage and the resection margin involvement of the frozen section diagnosis were the critical variables. Conclusions: When the tumor is located at the middle or the upper third, or the Lauren's indeterminate type, they are highly likely to show the resection margin involvement on the frozen section diagnosis, and it can, therefore, have negative effects on the prognosis. It is considered as good to perform more extensive resection as possible, during the initial resection.

Mycelial Growth and Fairy-Ring Formation of Tricholoma matsutake from Matsutake-Infected Pine Trees (송이 감염묘로부터 송이균의 생장과 균환 형성)

  • Ka, Kang-Hyeon;Hur, Tae-Chul;Park, Hyun;Kim, Hee-Su;Bak, Won-Chull
    • The Korean Journal of Mycology
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    • v.38 no.1
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    • pp.16-20
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    • 2010
  • Transplantation of matsutake-infected pine tree into a pine forest has great potential as an artificial cultivation method of Tricholoma matsutake. Matsutake-infected pine trees had previously transplanted by this research group into the experimental area from 2001 to 2004 and its survival rate determined in 2006 was 20%. For the survived samples, the characteristics of mycelial growth and the development of fairy-ring formation of T. matsutake have been evaluated until 2009. It was found that size of the indeterminate ring showed significant differences among the individual trees and varied from $4\;cm\;{\times}\;4\;cm$ to $52\;cm\;{\times}\;35\;cm$. The variation was possibly resulted from the differences in production area of the matsutake-infected pine tree and those in site characteristics of the transplanted spots. For the characteristics of mycelial growth, it grew in the shape of a cudgel or an acute-angled 'V' in early stage, and then the shape became more wider and changed into an obtuse-angled 'V' as time passed. We expect that matsutake mushrooms may occur from the fairy-rings of some of these matsutake-infected pine trees in the autumn of 2010.

Transbronchial Lung Cryobiopsy for Diagnosing Interstitial Lung Disease: A Retrospective Single-Center Experience

  • Park, Jin Han;Jang, Ji Hoon;Kim, Hyun Kuk;Jang, Hang-Jea;Lee, Sunggun;Kim, SeongHo;Kim, Ji Yeon;Choi, Hee Eun;Han, Ji-yeon;Kim, Da Som;Kang, Min Kyun;Kang, Eunsu;Kim, Il Hwan;Lee, Jae Ha
    • Tuberculosis and Respiratory Diseases
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    • v.85 no.4
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    • pp.341-348
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    • 2022
  • Background: An accurate diagnosis in patients with interstitial lung diseases (ILDs) by multidisciplinary discussion (MDD) based on histopathologic information is essential for optimal treatment. Transbronchial lung cryobiopsy (TBLC) has increasingly been used as a diagnostic alternative to surgical lung biopsy. This study aimed to evaluate the appropriate methods of TBLC in patients with ILD in Korea. Methods: A total of 27 patients who underwent TBLC were included. TBLC procedure details and clinical MDD diagnosis using TBLC histopathologic information were retrospectively analyzed. Results: All procedures were performed under general anesthesia with the fluoroscopic guidance in the operation room using flexible bronchoscopy and endobronchial balloon blocker. The median procedure duration was less than 30 minutes, and the median number of biopsies per participant was 2. Most of the bleeding after TBLC was not severe, and the rate of pneumothorax was 25.9%. The most common histopathologic pattern was alternative (48.2%), followed by indeterminate (33.3%) and usual interstitial pneumonia (UIP)/probable UIP (18.5%). In the MDD after TBLC, the most common diagnosis was idiopathic pulmonary fibrosis (33.3%), followed by smoking-related ILD (25.9%), nonspecific interstitial pneumonia (18.6%), unclassifiable-ILD (14.8%), and others (7.4%). Conclusion: This first single-center experience showed that TBLC using a flexible bronchoscopy and endobronchial balloon blocker with the fluoroscopic guidance under general anesthesia may be a safe and adequate diagnostic method for ILD patients in Korea. The diagnostic yield of MDD was 85.2%. Further studies are needed to evaluate the diagnostic yield and confidence of TBLC.

Useful Ultrasound Findings of Pediatric Patients with Equivocal Results of Appendicitis: Analysis Based on a Structured Report Form (애매한 초음파 결과를 보인 소아 환자에서 충수돌기염을 감별하는데 유용한 초음파 소견: 구조화 판독문에 기초한 분석)

  • Jiyoung Choi;Hyuk Jung Kim;Suk Ki Jang;Hyun Jin Kim;Jae Woo Yeon
    • Journal of the Korean Society of Radiology
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    • v.82 no.1
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    • pp.182-193
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    • 2021
  • Purpose To identify the features that can be used for differentiating appendicitis from non-appendicitis in pediatric patients with equivocal ultrasound (US) results. Materials and Methods A total of 53 pediatric patients (≤ 18 years old) with equivocal results on US examination for suspected appendicitis between November 2012 and October 2017 were included. US evaluation was conducted based on information retrieved from a predefined structured report form. Then, the likelihood of appendicitis was prospectively classified into five categories. The equivocal results were considered as grade 3 (indeterminate) and grade 4 (probably appendicitis). Results Of the 53 patients, 25 (47.2%) and 28 (52.8%) were classified into grade 3 and 4 groups, respectively. Among the individual US findings, increased vascularity of the appendiceal wall and peri-appendiceal fat infiltration were independent findings associated with the diagnosis of appendicitis (p = 0.005, p = 0.045, respectively) in the multivariate logistic regression analysis and showed the highest diagnostic accuracy (69.8% and 62.3%, respectively). Conclusion Increased vascularity within the appendiceal wall and peri-appendiceal fat infiltration were significant predictors of appendicitis in patients with equivocal US findings.

Comparison Between Contrast-Enhanced Computed Tomography and Contrast-Enhanced Magnetic Resonance Imaging With Magnetic Resonance Cholangiopancreatography for Resectability Assessment in Extrahepatic Cholangiocarcinoma

  • Jeongin Yoo;Jeong Min Lee;Hyo-Jin Kang;Jae Seok Bae;Sun Kyung Jeon;Jeong Hee Yoon
    • Korean Journal of Radiology
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    • v.24 no.10
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    • pp.983-995
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    • 2023
  • Objective: To compare the diagnostic performance and interobserver agreement between contrast-enhanced computed tomography (CECT) and contrast-enhanced magnetic resonance imaging (CE-MRI) with magnetic resonance cholangiopancreatography (MRCP) for evaluating the resectability in patients with extrahepatic cholangiocarcinoma (eCCA). Materials and Methods: This retrospective study included treatment-naïve patients with pathologically confirmed eCCA, who underwent both CECT and CE-MRI with MRCP using extracellular contrast media between January 2015 and December 2020. Among the 214 patients (146 males; mean age ± standard deviation, 68 ± 9 years) included, 121 (56.5%) had perihilar cholangiocarcinoma. R0 resection was achieved in 108 of the 153 (70.6%) patients who underwent curative-intent surgery. Four fellowship-trained radiologists independently reviewed the findings of both CECT and CE-MRI with MRCP to assess the local tumor extent and distant metastasis for determining resectability. The pooled area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of CECT and CE-MRI with MRCP were compared using clinical, surgical, and pathological findings as reference standards. The interobserver agreement of resectability was evaluated using Fleiss kappa (κ). Results: No significant differences were observed between CECT and CE-MRI with MRCP in the pooled AUC (0.753 vs. 0.767), sensitivity (84.7% [366/432] vs. 90.3% [390/432]), and specificity (52.6% [223/424] vs. 51.4% [218/424]) (P > 0.05 for all). The AUC for determining resectability was higher when CECT and CE-MRI with MRCP were reviewed together than when CECT was reviewed alone in patients with discrepancies between the imaging modalities or with indeterminate resectability (0.798 [0.754-0.841] vs. 0.753 [0.697-0.808], P = 0.014). The interobserver agreement for overall resectability was fair for both CECT (κ = 0.323) and CE-MRI with MRCP (κ = 0.320), without a significant difference (P = 0.884). Conclusion: CECT and CE-MRI with MRCP showed no significant differences in the diagnostic performance and interobserver agreement in determining the resectability in patients with eCCA.

Validation of CT-Based Risk Stratification System for Lymph Node Metastasis in Patients With Thyroid Cancer

  • Yun Hwa Roh;Sae Rom Chung;Jung Hwan Baek;Young Jun Choi;Tae-Yon Sung;Dong Eun Song;Tae Yong Kim;Jeong Hyun Lee
    • Korean Journal of Radiology
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    • v.24 no.10
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    • pp.1028-1037
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    • 2023
  • Objective: To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines. Materials and Methods: A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests. Results: The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593-14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719-65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07-420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%-100%) and positive predictive value (PPV) (91.8%-100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS. Conclusion: Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

A Study on the Characteristics of Oil-water Separation in Non-point Source Control Facility by Coalescence Mechanism of Spiral Buoyant Media (나선형 부유 고분자 여재의 Coalescence 특성을 이용한 비점오염원 저감시설의 유수분리특성 연구)

  • Kang, Sung-Won;Kim, Seog-Ku;Kim, Young-Im;Yun, Sang-Leen;Kim, Soo-Hae;Kim, Mee-Kyung
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.8
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    • pp.950-955
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    • 2007
  • Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.

Interpretation of Landscape Elements in Borimsa Temple after 17th Century (17세기 이후 장흥 보림사(長興 寶林寺)의 경관요소 해석)

  • Kim, Kyu-Won;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.1
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    • pp.110-118
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    • 2015
  • Borimsa Temple in Jangheung, one of the Goosanseonmoon of Shilla Dynasty, calls for a study in the field of landscape architecture because it has very significant elements in cultural and ecological landscaping aspects. This study examined the changes in landscaping elements of Borimsa Temple since the 17th century in order to newly recognize cultural landscaping value of space composition elements for traditional temple and to verify landscape architectural position. For research method, literatures such as Sajeonggi (事蹟記), Joongchanggi, a surveyed map by Fujishima Gaijiro in 1928 and Joseon Gojeogdobo (朝鮮古蹟圖譜) and modern documents including Borimsa Temple Precision Ground Survey Report and photographic records of National Archives of Korea and provincial governments were examined together with a field survey in order to trace changes in landscape elements such as buildings within the temple site, pond and temple forest. The results are as the following: First, for geographical locations of Borimsa Temple, it is located in an auspicious location and Shipyuknahansang and Cheonbul were placed in a supplementary purpose according to the contents of Bojoseonsatapbi. Compared to Namhwaseonsa Temple in China, it has a similar environmental composition but the fact that buildings were placed on platforms is a distinctive difference. Second, architectural landscape of Borimsa Temple went through the Japanese colonial era and Korean War and still going through changes today. Thus, there shall be some appropriate measures such as to establish an archive of past landscape data. Third, the contents of Borimsa Temple Sajeonggi suggests that the pond of Borimsa Temple had been in a indeterminate form with stones on the outer edge. Its name could have been Yongcheon (湧泉) according to the contents of Joongchanggi. Also, the current landscape, in comparison with past photographs, is a result of changes from surface raise occurred by ground reinforcement within the temple site. Fourth, Jangsaengpyoju (長生標柱) mentioned in Bojoseonsatapbi and Borimsa Temple Sajeonggi was thought to be the dried juniper tree in front of Daewoongbojeon, which can be found in past photographic documents but, it is now assumed to be Seokbihyeong (石碑形) considering the Gukjangsaeng and Hwangjangsaeng of Dogapsa Temple of the similar time period. Moreover, Hongsalmoon mentioned in Joongchanggi was established by King's order after the Manchu war of 1636 in praising of Buddhist monks those who had volunteered to fight for the country. Fifth, it is apparent in Borimsa Temple Joongchanggi that geomancy was a consideration in landscaping process of Borimsa Temple, and the record indicates that pine trees, bo trees and persimmon trees were planted. Sixth, tea tree forest was verified of its historical root that is Seongchailyeo from Unified Shilla through passing down of Jeong Yak-yong's Goojeunggoopo method and relevant documents of Seon Master Choui and Yi Yu-won. Seventh, nutmeg tree forest suggests that nutmegs were used in national ceremonies and for medical uses. The nutmeg tree forest was also verified of its role as Naehwasoorimdae (a forest built to prevent fire from spreading) through aerial photographs and placement of a forest reserve.