• Title/Summary/Keyword: Misinterpretation

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Minimizing MR Gradient Artefacts on ECG Signals for Cardiac Gating based on an Adaptive Digital Filter (적응 디지털 필터 기반의 MRI Cardiac Gating을 위한 심전도 신호의 MR Gradient 잡음 최소화 방법)

  • Park, Ho-Dong;Jang, Bong-Ryeol;Lee, Kyoung-Joung
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.817-818
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    • 2006
  • In Magnetic Resonance Imaging(MRI), the QRS complex of ECG is used as a trigger signal for MRI scan. But, gradient and RF(radio frequency) artifacts which are caused to static and dynamic field in MRI scanner cause interference in the ECG. Also, the signal shape of theses artifacts can be similar to the QRS-complex, causing possible misinterpretation during patient monitoring and false gating of the MRI. In case of using general FIR or IIR band-pass filters for minimizing the artifacts, artifact-reduction-ratio is not excellent. So, an adaptive real-time digital filter is proposed for reduction of noise by gradient and RF(radio frequency) artifacts. The proposed filter for MRI-Gating is based on the noise-canceller with NLMS(Normalized Least Mean Square) algorithm. The reference signals of the adaptive noise canceller are a combination of the noisy three channel ECG signals. In conclusions, the proposed method showed the acceptable quality of ECG signal with sufficient SNR for gating the MRI and possibility of real time implementation.

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Formal Governance Mechanism and its Application in Construction Projects

  • Banihashemi, Seyed Yaser;Liu, Li
    • Journal of Construction Engineering and Project Management
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    • v.3 no.1
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    • pp.22-27
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    • 2013
  • Inter-organizational Relationships (IORs) governance is one of the emerging research areas that have been studied in different contexts (e.g. economics, strategy, organization, and management). This view, particularly, attracted rising attention from academics and practitioners in the context of construction projects, due to the complex forms of IORs in terms of inter-firm exchanges (e.g. engineering, procurement, finance, construction, and operation) in these projects. The focus of IORs governance is to control Inter-organizational relationships among two or more cooperative parties to alleviate conflict and achieve mutual gains. One of the mechanisms that have been identified in the related literature is formal governance mechanism. Although many empirical studies have been conducted using formal governance terms and indicators, there isn't yet a consensual definition of this mechanism and its components that may cause misinterpretation of research results and also impede future research. This paper makes contribution to the concept of IORs governance by clarifying the meaning of formal governance mechanism and identifying different indicators of this mechanism that have been used and identified in previous studies. This provides an innovative and useful framework to understand formal governance mechanism and its application in construction projects.

Content Analysis of the Questionnaires Used in Dietary Surveys (식생활 조사연구에 사용된 설문지의 내용 분석)

  • 김기남;김애정;박은숙;우미경;이보경;현태선
    • Korean Journal of Community Nutrition
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    • v.5 no.4
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    • pp.697-708
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    • 2000
  • The purpose of this study is to analyze the contents of the questionnaires used in dietary surveys and to evaluate each item in relation to the item construction strategy. Articles of which the contents were related to food, nutrition, diet, dietary behavior, and related areas. Published from 1997 to 1999 were searched fir and a total of 121 questionnaires were collected and analyzed. The questions in the questionnaires were classified into related areas and sub-areas. Among the keywords in the title of the articles, the term 'nutritional status'(or 'dietary intake status') was most frequently used. The terms such as dietary status, obesity, health, food habit, and dietary behavior were also frequency used. Major topics of the items in the questionnaires varied according to the life cycle of the subjects of the study. The topics most frequently asked in each lift cycle were as follows : overeating, snack, and food preference for preschool- and school-aged children ; anthropometry, weight control, and snack for middle and highschool students : meal skipping, smoking, and drinking for college students : disease, smoking, drinking, and exercise for adults : and smoking, drinking, disease and perceived health for the elderly. Inappropriate questions with complicated language, typographic and grammatic errors, unnecessary words, and negative questions were found. Therefore, care should be taken to construct each question so as to avoid possible misinterpretation. Also, a standardized questionnaire be developed for survey researchers.

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Should Workers Avoid Consumption of Chilled Fluids in a Hot and Humid Climate?

  • Brearley, Matt B.
    • Safety and Health at Work
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    • v.8 no.4
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    • pp.327-328
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    • 2017
  • Despite provision of drinking water as the most common method of occupational heat stress prevention, there remains confusion in hydration messaging to workers. During work site interactions in a hot and humid climate, workers commonly report being informed to consume tepid fluids to accelerate rehydration. When questioned on the evidence supporting such advice, workers typically cite that fluid absorption is delayed by ingestion of chilled beverages. Presumably, delayed absorption would be a product of fluid delivery from the gut to the intestines, otherwise known as gastric emptying. Regulation of gastric emptying is multifactorial, with gastric volume and beverage energy density the primary factors. If gastric emptying is temperature dependent, the impact of cooling is modest in both magnitude and duration (${\leq}5$ minutes) due to the warming of fluids upon ingestion, particularly where workers have elevated core temperature. Given that chilled beverages are most preferred by workers, and result in greater consumption than warm fluids during and following physical activity, the resultant increased consumption of chilled fluids would promote gastric emptying through superior gastric volume. Hence, advising workers to avoid cool/cold fluids during rehydration appears to be a misinterpretation of the research. More appropriate messaging to workers would include the thermal benefits of cool/cold fluid consumption in hot and humid conditions, thereby promoting autonomy to trial chilled beverages and determine personal preference. In doing so, temperature-based palatability would be maximized and increase the likelihood of workers maintaining or restoring hydration status during and after their work shift.

FORMAL GOVERNANCE MECHANISM AND ITS APPLICATION IN CONSTRUCTION PROJECTS

  • S. Yaser Banihashemi;Li Liu
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.321-327
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    • 2013
  • Inter-organizational Relationships (IORs) governance is one of the emerging research areas that have been studied in different contexts (e.g. economics, strategy, organization, and management). This view, particularly, attracted rising attention from academics and practitioners in the context of construction projects, due to the complex forms of IORs in terms of inter-firm exchanges (e.g. engineering, procurement, finance, construction, and operation) in these projects. The focus of IORs governance is to control Inter-organizational relationships among two or more cooperative parties to alleviate conflict and achieve mutual gains. One of the mechanisms that have been identified in the related literature is formal governance mechanism. Although many empirical studies have been conducted using formal governance terms and indicators, there isn't yet a consensual definition of this mechanism and its components that may cause misinterpretation of research results and also impede future research. This paper makes contribution to the concept of IORs governance by clarifying the meaning of formal governance mechanism and identifying different indicators of this mechanism that have been used and identified in previous studies. This provides an innovative and useful framework to understand formal governance mechanism and its application in construction projects.

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Comparison of Loss Function for Multi-Class Classification of Collision Events in Imbalanced Black-Box Video Data (불균형 블랙박스 동영상 데이터에서 충돌 상황의 다중 분류를 위한 손실 함수 비교)

  • Euisang Lee;Seokmin Han
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.1
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    • pp.49-54
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    • 2024
  • Data imbalance is a common issue encountered in classification problems, stemming from a significant disparity in the number of samples between classes within the dataset. Such data imbalance typically leads to problems in classification models, including overfitting, underfitting, and misinterpretation of performance metrics. Methods to address this issue include resampling, augmentation, regularization techniques, and adjustment of loss functions. In this paper, we focus on loss function adjustment, particularly comparing the performance of various configurations of loss functions (Cross Entropy, Balanced Cross Entropy, two settings of Focal Loss: 𝛼 = 1 and 𝛼 = Balanced, Asymmetric Loss) on Multi-Class black-box video data with imbalance issues. The comparison is conducted using the I3D, and R3D_18 models.

MRI-Based Stepwise Approach to Anterior Mediastinal Cystic Lesions for Diagnosis and Further Management

  • Jong Hee Kim;Jooae Choe;Hong Kwan Kim;Ho Yun Lee
    • Korean Journal of Radiology
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    • v.24 no.1
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    • pp.62-78
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    • 2023
  • As the majority of incidentally detected lesions in the anterior mediastinum is small nodules with soft tissue appearance, the differential diagnosis has typically included thymic neoplasm and prevascular lymph node, with benign cyst. Overestimation or misinterpretation of these lesions can lead to unnecessary surgery for ultimately benign conditions. Diagnosing mediastinal cysts using MRI serves as a problem-solving modality in distinguishing between surgical and nonsurgical anterior mediastinal lesions. The pitfalls of MRI evaluation for anterior mediastinal cystic lesions are as follows: first, we acknowledge the limitation of T2-weighted images for evaluating benign cystic lesions. Due to variable contents within benign cystic lesions, such as hemorrhage, T2 signal intensity may be variable. Second, owing to extensive necrosis and cystic changes, the T2 shine-through effect may be seen on diffusion-weighted images (DWI), and small solid portions might be missed on enhanced images. Therefore, both enhancement and DWI with apparent diffusion coefficient values should be considered. An algorithm will be suggested for the diagnostic evaluation of anterior mediastinal cystic lesions, and finally, a management strategy based on MRI features will be suggested.

Highlight Detection Using Photometric Stereo and Object Reconstruction Using Difference Image (측광입체시법을 이용한 하이라이트 검출과 농담 차이를 이용한 물체 복원)

  • Bae, Cheol-Min;Mun, Yeong-Sik
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.4
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    • pp.1132-1140
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    • 1997
  • In many vision tasks of the major obstacles is the specular highkight of smoth objects, which causes a misinterpretation of objects.This paper presents an dffcient algorithm for highight detection and object reconstruction, blsed on the theory of photometric stereo in which the location of highilight changes as the position of illumination source changes.Two images, referred to as base image and reference image.are sequentially taken with two different positionhs of the two images.The difference image is thresholded to detct the specular spike of the highlight.Then the specu-lar lobe around the specular spike is detected to reconstruct the object.The proposed algorithm can be applied to metals and dielectrics, regardlless of the surface chracteristics.This method can also be aplied to the case when the background is brighter than the object.

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The Interpreggtation of the Indian Stupa as Origin of Korean Pagoda (탑의 원조 인도 스투파의 형태 해석 - 인도 전역의 현장 답사를 바탕으로 -)

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.18 no.6
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    • pp.103-126
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    • 2009
  • This study aims to discover historical trends and change of form of all stupas in India with observation of field study that is as direct as possible, by classifying, analyzing, and synthesizing the stupas. Study of Indian stupa in Korea has a number of shortcomings since only introductory partial approach has been made in order to seek the origin of Korean pagoda. This study also aims to correct errors of stupa terminology in Chinese character committed by misinterpretation of Hindi language which was established by precedent Japanese scholars several decades ago. Piled-up stupas were totally destroyed by pagans, therefore their remains tell us only of structure, material, sizeand disposition. However remains of carved stone at torana and drum give us clues as to the original form of stupa and worshipping activity, as well as change to a more luxurious form. Many rock cave stupas of India show us both simple forms matching the ascetic age of early Buddhism and luxurious changes in Mahayanan era introducing us to statues of Buddha. Indians recovered the spheric form of 'anda,' a Hindi term meaning cosmic egg, from the hemispheric form of the piled-up stupa. Therefore we might discard the erratic term of 'bokbal', which means an upset vessel. Railings and parasols became main factors of stupa design. Carved railings around stupa became a sign of divinity. Serious worshipping activity made drums long or high and created multi-embossed stripes. Bases of circular drums of some cave stupas changed their shapes to rectangular or octagonal. Single parasols became multiparasols of affluent flowerlike curved stems on carved stupa. Multistoried, elongated and high parasols of Gandhara stupas are closely related to such factors as diverse changes of form in Indian subcontinent. Four-sided torana gate and ayaka column of the circular form of original stupas suggest the rectangular form of subsequent East Asian pagoda, and higher and wider base of Indian stupas became the origin of East Asian rectangular pagoda.

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Diagnostic Usefulness of Fine Needle Aspiration Cytology on Lymphadenopathy (림프절종대의 세침흡인 세포검사의 진단적 유용성 - 림프절의 세침흡인 세포검사 1,216예의 분석 -)

  • Kim, Dong-Won;Jin, So-Young;Lee, Dong-Hwa;Lee, Chan-Soo
    • The Korean Journal of Cytopathology
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    • v.8 no.1
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    • pp.11-19
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    • 1997
  • Clinical lymphadenopathies are subjected to fine needle aspiration cytology(FNAC) for diagnosing not only benign lesions but also malignant ones, as the first diagnostic procedure. While the diagnostic reliability in metastatic carcinoma is high, it is difficult to differentiate malignant lymphoma from reactive conditions. We evaluated the diagnostic reliability of FNAC in lymphadenopathy, and discuss the diagnostic limitation and its place in clinical practice in this study, Over 8 years from January 1988, FNAC of 1,216 lymphadenopathies were analyzed and among them 170 cases were compared with histopathology. The results are as follows. 1. Of ail the cases, 890 cases(73.2%) were diagnosed cytologically as benign, 312 cases(25.7%) as malignant, and 14 cases(1.1%) as unsatisfactory material. Reactive hyperplasia was diagnosed in 585 cases(65.7%) of the benign lesions, and among the malignant diseases, metastatic carcinoma was diagnosed in 248 cases(79.5%), and malignant lymphoma in 62 cases(19.9%). 2. The overall diagnostic accuracy was 89.2%, and no false positive case and 9 false negative results were observed among 170 cases which were proven by histopathology. Six cases of sampling error of false negative diagnoses included 3 of metastatic carcinomas and 3 of malignant lymphomas. The causes were difference between aspiration and biopsy site, poor fixation, or scanty cellularity with bloody smear. All 3 cases of misinterpretation error were malignant lympliomas, one of mixed type on biopsy which was diagnosed as reactive hyperplasia cytologically. In summary, FNAC technique is thought to be useful in the initial diagnosis of lymphadenopathies as well as in the follow-up of patients with known malignancy. Although the results of malignant lymphoma was less accurate than other malignant lesions, the application of strict cytologic criteria or lymphoid marker studies of aspiration material will reduce the false negative rate.

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