• Geomechanics and Engineering
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• 제31권2호
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• pp.183-195
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• 2022

Under the effects of the near-field earthquakes, the incident angle of the incoming wave could be different. In this study, the influences of some parameters such as incident angle, basin edge, peak ground acceleration level of the bedrock motion as well as different clay types with different consistency on the amplification behavior of the shallow basins are investigated. To attain this goal, the numerical analyses of the basins filled with three different clay types are performed using a fully nonlinear method. The two dimensional models of the basins are subjected to a set of strong ground motions with different peak ground acceleration levels and three different incident angles of 30◦, 45◦ and 90◦ with respect to the horizontal axes. The results show the dominant effect of the obliquely subjected waves at most cases. The higher effect of the 45◦ incident angle on the basin response was concluded. In the other part of this study, the spectral amplification curves of the surface points were compared. It was seen that the maximum spectral amplification of different surface points occurs at different periods. Also, it is affected by the increase in the peak acceleration level of the incoming motions.

• Physical Therapy Rehabilitation Science
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• 제12권3호
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• pp.251-258
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• 2023

Objective: The practice of breathing exercises involves altering the depth and frequency of respiration. Strengthening respiratory muscles plays a crucial role in maintaining overall health and well-being. The efficiency of the respiratory system affects not only physical activity but also various physiological processes including cardiovascular health, lung function, and cognitive abilities. The study evaluated the reliability of the developed device for inspiratory/expiratory training using pressure sensors and Bluetooth connectivity with a smartphone application. Design: Design & development research Methods: The research methodology involved connecting a custom-made respiratory sensor to an IMT-PEP BIC Breath device. Various pressure conditions were measured, and statistical analyses were performed to assess reliability and consistency. Results showed high Intraclass Coefficient Correlation (ICC) values for both inspiratory and expiratory pressures, indicating strong test-retest reliability. The device was designed for ease of use and wireless monitoring through a smartphone app. Results: This study conducted at expiratory pressure confirmed the proper operation of the IMT/PEP breathing trainer at the specified pressure setting in the product. The pressure sensor demonstrated high test-retest reliability with an ICC value of 0.999 for both expiratory and inspiratory pressure measurements. Conclusions: The developed respiratory training device measured and monitored inspiratory and expiratory pressures, demonstrating its reliability for respiratory training. The system could be utilized to record training frequency and intensity, providing potential benefits for patients requiring respiratory interventions. Further research is needed to assess the full potential of the device in diverse populations and applications.

• Investigative Magnetic Resonance Imaging
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• 제24권1호
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• pp.38-45
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• 2020

Background: Differentiation of cerebellopontine angle (CPA) schwannoma from meningioma is often a difficult process to identify. Purpose: To identify imaging features for distinguishing CPA schwannoma from meningioma and to investigate the usefulness of susceptibility-weighted imaging (SWI) in differentiating them. Materials and Methods: Between March 2010 and January 2015, this study pathologically confirmed 11 meningiomas and 20 schwannomas involving CPA with preoperative SWI were retrospectively reviewed. Generally, the following MRI features were evaluated: 1) maximal diameter on axial image, 2) angle between tumor border and adjacent petrous bone, 3) presence of intratumoral dark signal intensity on SWI, 4) tumor consistency, 5) blood-fluid level, 6) involvement of internal auditory canal (IAC), 7) dural tail, and 8) involvement of adjacent intracranial space. On CT, 1) presence of dilatation of IAC, 2) intratumoral calcification, and 3) adjacent hyperostosis were evaluated. All features were compared using Chi-squared tests and Fisher's exact tests. The univariate and multivariate logistic regression analysis were performed to identify imaging features that differentiate both tumors. Results: The results noted that schwannomas more frequently demonstrated dark spots on SWI (P = 0.025), cystic consistency (P = 0.034), and globular angle (P = 0.008); schwannomas showed more dilatation of internal auditory meatus and lack of calcification (P = 0.008 and P = 0.02, respectively). However, it was shown that dural tail was more common in meningiomas (P < 0.007). In general, dark spots on SWI and dural tail remained significant in multivariate analysis (P = 0.037 and P = 0.012, respectively). In this case, the combination of two features showed a sensitivity and specificity of 80% and 100% respectively, with an area under the receiver operating characteristic curve of 0.9. Conclusion: In conclusion, dark spots on SWI were found to be helpful in differentiating CPA schwannoma from meningioma. It is noted that combining dural tail with dark spots on SWI yielded strong diagnostic value in differentiating both tumors.

• 대한치과보철학회지
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• 제42권2호
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• pp.192-209
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• 2004

Purpose : The purpose of this study was to evaluate the machining accuracy and consistency of implant/abutment/screw combination or internal connection type. Material and methods: In this study, each two randomly selected internal implant fixtures from ITI, 3i, Avana, Bicon, Friadent, Astra, and Paragon system were used. Each abutment was connected to the implant with 32Ncm torque value using a digital torque controller or tapping. All samples were cross-sectioned with grinder-polisher unit (Omnilap 2000 SBT Inc) after embeded in liquid unsaturated polyester (Epovia, Cray Valley Inc). Then optical microscopic and scanning electron microscopic(SEM) evaluations of the implant-abutment interfaces were conducted to assess quality of fit between the mating components. Results : 1) Generally, the geometry of the internal connection system provided for a precision fit of the implant/abutment into interface. 2) The most precision fit of the implant/abutment interface was provided in the case of Bicon System which has not screw. 3) The fit of the implant/abutment interface was usually good in the case of ITI, 3I and Avana system and the amount of fit of the implant/abutment interface was similar to each other. 4) The fit of the implant/abutment interface was usually good in the case of Friadent, Astra and Paragon system. The case of Astra system with the inclined contacting surface had the most Intimate contact among them. 5) Amount of intimate contact in the abutment screw thread to the mating fixture was larger in assembly with two-piece type which is separated screw from abutment such as Friadent, Astra and Paragon system than in that with one-piece type which is not seperated screw from abutment such as ITI, 3I and Avana system. 6) Amount of contact in the screw and the screw seat of abutment was larger in assembly of Friadent system than in asembly of Astra system of Paragon system. Conclusion: Although a little variation in machining accuracy and consistency was noted in the samples, important features of all internal connection systems were the deep, internal implant-abutment connections which provides intimate contact with the implant walls to resist micro-movement, resulting in a strong stable interface. From the results of this study, further research of the stress distribution according to the design of internal connection system will be required.

• 동의생리병리학회지
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• 제18권2호
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• pp.376-380
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• 2004

The purpose of this study is the develop a questionnaire for measuring Yin-Deficiency and examine the reliability and validity for its' value as a barometer for evaluating Yin-Deficiency. Questionnaire was developed according to the symptoms of Yin-Deficiency suggested in the 'Standardization of diagnostic terms and requirements of Korean Medicine', With and as a reference, each symptom has been worked on to be put on the questionnaire. Visual analogue scales(VAS) was used as a barometer for measuring frequency of manifestation of symptoms. A study was performed to measure validity and reliability of the final questionnaire for analysis. reliability of YinDQ was measured by Cronbach's alpha coefficient and test-retest method. This study utilized factor analysis and clinical validity for evaluation of validity. For the purpose of decreasing the amount of data-the number of factors, and at the same time minimize the loss of information factor analysis was performed Component factors were extracted using Principal Component Analysis. This study evaluated the clinical validity for examination of difference between the normal group and the patient group. Evaluation on the's internal consistency showed strong internal consistency with value of 0.8615. reliability from test-rest with three-week interval, followed by comparisons of the correlation coefficient and mean values of each item between the two. The Spearman correlation coefficient was 0.54-0.79. By factor analyse two factors with Eigen value of greater than 2.2 were selected. Factor 1 consists of items of 'irritable fever on the five Hearts', 'flushing of the zygomatic region in the afternoon', 'tidal fever', 'night sweats', and 'dryness on the mouth or the throat'. Factor two consists of items of 'emaciation', 'dizziness', 'insomnia', 'decreased amount of urine with yellowish color', and 'constipation'. The comparison between the patient group and the normal group showed significant differences for every ten questions. The results implies that YinDQ is a barometer with sufficient reliability and validity. The questionnaire for Yin-Deficiency may not be enough to replace the specific differential diagnosis by a doctor of Oriental medicine. Nevertheless, it can be effectively utilized as an assisting method in consultation or a method of measuring the degree of Yin-Deficiency in a group.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 1999년도 추계학술발표회 초록집
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• pp.15-15
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• 1999

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the conventional rotating barrel. vibrational barrel (vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components, The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed that the average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value, Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components, However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. $2HD{\;}+{\;}e{\;}{\rightarrow}20H{\;}+{\;}H_2$ Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure thereby resulting to bad plating condition. 1 lot of chip was divided into two equal partion. Each portion was loaded to the same barrel one after the other. Nickel plating and tin-lead plating was performed in the same station. Portion A maintained the normal barrel vibration intensity and portion B vibration intensity was increased two steps higher. All other parameters, current, solution condition were maintained constant. Generally, plating method find procedures were carried out in a best way to maintained the best plating condition. After plating, samples were taken out from each portion. molded and polished. Plating thickness was investigated for both. To check consistency of results. 2nd trial was done now using different lot of another characteristics.

• 한국도로학회논문집
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• 제17권3호
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• pp.49-58
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• 2015

PURPOSES : The use of environmentally friendly construction methods has been recently encouraged to reduce fuel consumption and the effects of global warming. For this purpose, the roller compacted concrete pavement (RCCP) construction method has been developed. RCCP is more environmentally friendly and economically efficient than general concrete by reducing the amount of CO2 generated through the application of a smaller amount of cement. RCCP has a number of advantages such as an easy construction method, low cost, high structural hydration performance, and aggregate interlocking. However, mix design standards and construction guidelines of RCCP are required for domestic application. In addition, a study on aggregate selection, which has an effect on the characteristics of RCCP, is necessary owing to a limited number of researches. Thus, the aggregate effect on the performance of RCCP in securing the required strength and workability was evaluated in consideration of domestic construction. METHODS : Sand and coarse aggregates of both 19mm and 13mm in maximum size were used in this study. Four types of aggregate gradations (s/a = 30%, 58%, and 70% for the sand and coarse aggregate of 19mm in maximum size, and s/a = 50% for a combination of the three types of aggregates) were set up to investigate the effects of the PCA band on the RCC characteristics. The conditions of s/a = 30% and 70% were evaluated to check the gradation effect outside of the recommended band. The conditions of s/a = 58% and 50% were used because they are the optimum combination of the two and three types of aggregates, respectively. RCCP gradation band was suggested gradation with a proper construction method of RCCP by synthetically comparing and analyzing the correlation of optimum water content, maximum dry density, and strength of requirements through its consistency and compaction test. RESULTS : The lower and upper limit lines are insufficient to secure a relatively strong development and workability compared to an aggregate gradation in the RCCP gradation band region. On the other hand, the line in the RCCP gradation band and the 0.45 power curve in the RCCP gradation band region were satisfactory, ensuring the required strength and workability. CONCLUSIONS : The suitable aggregate gradation on RCCP process should meet the RCCP gradation band area; however, fine particles passing through a #60 sieve do not need to be within the recommended gradation band because the influence of this region on such fine particles is small.

• 한국의료질향상학회지
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• 제3권1호
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• pp.104-124
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• 1996

Background : In these days, the health care organizations have concerned about customer-centered care in order to empower the competitiveness on the health care markets. The departments working for quality management of the hospitals have used health care quality indicators in terms of medical areas as well as service areas of the hospitals. However, there were insufficient efforts to develop the credible measurement to seek the customers' needs, their expectations and their satisfaction levels related to health care services because various kinds of challenges were in the process of scale development to measure customers' satisfaction in health care. The purpose of this study was to develop the satisfaction scale to health care services in a Korea health care organization and to test its tool with validity and reliability. Method : The concept of this tool was acceptability that one of the components of health care quality defined by Donabedian. Acceptability has the five dimensions of concept: Accessibility; Patient-Practitioner Relations; Amenities; Patient Preferences as to the effects of care; and Patient Preferences as to the costs of care. The Satisfaction Tool to Health Care Services was reviewed by expert panel with five researchers, including hospital managers and a professor related to quality management of the hospitals. As a result, the content validity index was .84 in the outpatient satisfaction tool. The inpatient satisfaction tool had .87 of the content validity index. The Satisfaction Tools to Health Care Services finally consisted of 44 items for outpatients/their families and of 60 items for inpatients/their families. Study subjects of the construct validity test were 479 outpatients/their families and 561 inpatients/their families who visited or admitted at a University hospital from July 1, 1996 through August 10, 1996. The data were examined by Factor Analysis with SPSS. Result : The items of Satisfaction tools for outpatients/their families were categorized by eleven factors with eigenvalue greater than 1.0 accounting for 64.2 percent of the variation in item scores. Also, the items of inpatient tool had eleven factors with eigenvalue greater than 1.0 accounting for 60.3 percent of the variation in item scores. The reliability of overall scale were .95 and .96 for the outpatients/their families satisfaction scores and inpatient/their families satisfaction scores. The internal consistency reliability with eleven factors was ranged from .30 to .94 for inpatients/their families. The Satisfaction Tool with eleven factors for inpatients/their families had internal consistency reliability ranged from .53 to .89. Conclusion : The Satisfaction Tools to Health Care Services focused on outpatients/their families and inpatients/their families developed in this study had a high reliability and the strong evidence of content validity and construct validity based on quality concept. Therefore, this tool would be utilized as a credible quality indicator of health care services to assess the quality problems and to monitor the quality improvement activities in Korean Health Care Organizations.

• 한국수자원학회논문집
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• 제54권5호
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• pp.301-309
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• 2021

본 연구에서는 시계열 순서의 의미가 희석될 수 있는 기존의 U-net 기반 딥러닝 강우예측 모델의 성능을 개선하고자 하였다. 이를 위해서 데이터의 연속성을 고려한 ConvLSTM2D U-Net 신경망 구조를 갖는 모델을 적용하고, RainNet 모델 및 외삽 기반의 이류모델을 이용하여 예측정확도 개선 정도를 평가하였다. 또한 신경망 기반 모델 학습과정에서의 불확실성을 개선하기 위해 단일 모델뿐만 아니라 10개의 앙상블 모델로 학습을 수행하였다. 학습된 신경망 강우예측모델은 현재를 기준으로 과거 30분 전까지의 연속된 4개의 자료를 이용하여 10분 선행 예측자료를 생성하는데 최적화되었다. 최적화된 딥러닝 강우예측모델을 이용하여 강우예측을 수행한 결과, ConvLSTM2D U-Net을 사용하였을 때 예측 오차의 크기가 가장 작고, 강우 이동 위치를 상대적으로 정확히 구현하였다. 특히, 앙상블 ConvLSTM2D U-Net이 타 예측모델에 비해 높은 CSI와 낮은 MAE를 보이며, 상대적으로 정확하게 강우를 예측하였으며, 좁은 오차범위로 안정적인 예측성능을 보여주었다. 다만, 특정 지점만을 대상으로 한 예측성능은 전체 강우 영역에 대한 예측성능에 비해 낮게 나타나, 상세한 영역의 강우예측에 대한 딥러닝 강우예측모델의 한계도 확인하였다. 본 연구를 통해 시간의 변화를 고려하기 위한 ConvLSTM2D U-Net 신경망 구조가 예측정확도를 높일 수 있었으나, 여전히 강한 강우영역이나 상세한 강우예측에는 공간 평활로 인한 합성곱 신경망 모델의 한계가 있음을 확인하였다.

• 예술인문사회 융합 멀티미디어 논문지
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• 제6권2호
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• pp.197-208
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• 2016

이 연구에서는 쓰기에 어려움이 있는 장애학생을 위한 K-HHIW의 측정학적 적합성 탐색을 위해 장애학생을 대상으로 신뢰도와 타당도 검증을 실시하였다. 연구를 위해 번안된 쓰기 자기평가 검사를 국내 특수교육 분야 전문가 40명에게 델파이 조사하였으며, 적합한 21개 문항으로 최종문항을 완성하였다. 이후 개발된 K-HHIW에 대해 장애학생과 비장애학생 350명(장애학생 116명, 비장애학생 234명)이 참여하여 내적합치도 신뢰도 계수를 산출하고, 구인 타당도 검증을 위해 확인적 요인분석을 실시하였다. 연구결과 장애학생의 전체 신뢰도지수는 .927로 비장애학생 신뢰도지수 .889에 비해 높게 나타났으며, 두 집단 모두 하위요인의 신뢰도가 .661에서 .911로 분포하여 비교적 양호한 것으로 나타났다. 또한 K-HHIW의 확인적 요인분석 결과, 장애학생의 경우 RMSEA는 .08로 적합한 수준이며 GFI, CFI, NFI는 비장애학생과 비교했을 때 다소 낮지만 적합한 수준으로 나타났다. 또한 비장애학생의 자기평가 척도의 하위요인에 있어 집중타당성 수준은 양호한 것으로 나타난 반면 장애학생의 경우 비장애학생의 비해 집중타당성 수준이 낮은 것으로 제시되었다. 마지막으로, 비장애학생의 경우 척도의 하위요인 간 어느 정도의 판별타당성이 검증된 반면 장애학생의 경우 신체수행능력과 쓰기수행 하위척도의 판별타당성은 다소 낮은 것으로 나타났다.