• 종양간호연구
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• 제12권1호
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• pp.20-26
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• 2012

Purpose: The purpose of this study was to identify the stress and the coping strategies in breast cancer patients and their spouses. Methods: The stress level was measured by the Stress Questionnaire of Andersson & Albertsson (2000). The coping strategies were measured by the modified Lazarus & Folkman's Ways of Coping Questionnaire. The data were collected by a survey sampling 49 couples from one hospital in Seoul. The data were analyzed by t-test, ANOVA and paired t-test. Results: There was no significant differences between the stress level of breast cancer patients and their spouses. The problem-focused coping of breast cancer patients was significant higher than their spouses. The cancer patients and their spouses used problem-focused coping mode more than emotion-focused coping mode. In the problem-focused coping mode, breast cancer patients used two coping strategies - 'seeking information' and 'cognitive reconstruction' - significantly more than their spouses. In emotion-focused coping mode, the breast cancer patients used one coping strategy, 'emotional expression', significantly more than the their spouses. Conclusion: Further study needs to attempt to develop nursing interventions that could improve positive coping strategies.

• Structural Monitoring and Maintenance
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• 제4권2호
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• pp.115-131
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• 2017

Classical flutter of wind turbine blades indicates a type of aeroelastic instability with fully attached boundary layer where a torsional blade mode couples to a flapwise bending mode, resulting in a mutual rapid growth of the amplitudes. In this paper the monitoring problem of onset of flutter is investigated from a detection point of view. The criterion is stated in terms of the exceeding of a defined envelope process of a specific maximum torsional vibration threshold. At a certain instant of time, a limited part of the previously measured torsional vibration signal at the tip of blade is decomposed through the Empirical Mode Decomposition (EMD) method, and the 1st Intrinsic Mode Function (IMF) is assumed to represent the response in the flutter mode. Next, an envelope time series of the indicated modal response is obtained in terms of a Hilbert transform. Finally, a flutter onset criterion is proposed, based on the indicated envelope process. The proposed online flutter monitoring method provided a practical and direct way to detect onset of flutter during operation. The algorithm has been illustrated by a 907-DOFs aeroelastic model for wind turbines, where the tower and the drive train is modelled by 7 DOFs, and each blade by means of 50 3-D Bernoulli-Euler beam elements.

• 통합자연과학논문집
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• 제1권2호
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• pp.79-83
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• 2008

As a new standard for performance measurement, NEMA NU2-2001 was presented recently. In this study, I investigated the spatial resolution, sensitivity, scatter fraction, and noise equivalent count ratio (NECR) in order to know the information of physical characteristics and system performance of GE discovery ST using this new standard. Bismuth germinate crystals ($6{\times}6$ array, $6.3mm{\times}6.3mm{\times}30mm$) were used in discovery ST (energy window:375-650 keV, coincidence window:11.7 nsec). To measure the sensitivity, five aluminum sleeves (Data Spectrum Corp., Chapel Hill, NC., USA, thickness:1.25 mm)-NEMA sensitivity phantom- filled with F-18 solution were used. Successive measurements in 2D and 3D acquisition mode were made with a line source at the center of transaxial field of view and 10 cm off from the center until the count was over 500,000. Spatial resolution was estimated using a point source (F-18, 0.1 mCi) at different locations in the FOV. Scatter fraction and NECR was tested using a NEMA scatter phantom. Dynamic data were acquired for 7 half-lives using F-18 solution. And true to background ratio was averaged at last three frames when the random rate was as small as ignorable for the calculation of scatter fraction. We anticipate this overall evaluated results could be used for the quality assurance and optimized image acquisition for clinical research.

• 지구물리와물리탐사
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• 제15권4호
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• pp.155-162
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• 2012

기반암의 상부 토양층에 협재하는 속도이상층이 레일리파 위상속도와 수직변위의 스펙트럼 진폭에 미치는 영향을 분석하기 위하여 Thomsen-Haskell 방법을 사용하였다. 기본모델은 횡파속도(${\nu}_s$) 300 m/s의 토양층이 9 m 두께로 ${\nu}_s$가 1000 m/s인 반무한 기반암 위에 쌓여 있다. 토양층 내에 두께 1, 2, 3 m, S파속도 150, 225, 375, 450 m/s인 삽입층은 지표부터 깊이 1 m 간격으로 놓여있다. 레일리파 위상속도($C_R$)는 4 ~ 30 Hz 주파수 구간에서 계산하였다. 삽입층 모델은 두께가 1 m일 때, 기본모델과 삽입모델의 위상속도 차이인 ${\Delta}C_R$에 민감하게 반응하는 주파수 대역은 8 ~ 20 Hz이며, 이 주파수 대역은 삽입층의 두께가 증가할수록 넓어진다. 1차 고차모드의 저주파 차단주파수 바로 위의 주파수 구간을 제외하면, 모든 모델에서 기본모드의 스펙트럼 진폭이 1차 고f차모드보다 크다.

• 비파괴검사학회지
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• 제18권1호
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• pp.33-41
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• 1998

유리모세관의 파괴시에 방출되는 탄성파를 이용하여 유리평판의 진앙점에 위치한 PZT변환기의 응답특성을 연구하였다. PZT변환기는 일정한 면적을 가지고 두께가 다른 PZT 세라믹 (Edo사의 EC-65)을 사용하여 제작하였다. 공기 경계층을 갖는 유리평판에서 힘의 크기가 1 N이고 상승시간이 280ns인 경사 점하중이 인가된 경우에 대하여 진앙점에서 수직 성분의 변위와 속도를 이론적으로 계산하였다. PZT변환기의 과도응답은 이론적으로 계산된 수직 성분의 속도가 입사하여 PZT세라믹의 전극과 만날 때 펄스형태로 나타난다고 생각할 수 있다. PZT변환기의 응답은 PZT세라믹의 직경 대 두께의 비가 약 0.33 이하인 경우에는 두께진동모드에만 의존하고, 그 이상의 경우에는 두께진동모드와 다른 저주파수의 진동 모드의 중첩에 의해서 일어난다고 생각된다. 첫 펄스의 반폭치시간은 인가된 파괴하중과 PZT변환기의 공진주파수에 무관하게 약 280ns로서 일정하였고, 음향방출 발생원의 상승시간으로 생각할 수 있었다. 첫 펄스의 최대진폭은 PZT변환기에 입사하는 수직 성분의 속도와 PZT세라믹의 축전용량에 비례하였다. 그러므로, 동일한 PZT변환기에 대하여 음향방출 발생원의 상승시간과 크기는 첫 펄스의 반폭치시간과 최대 진폭으로 평가할 수 있다.

• 한국전기전자재료학회논문지
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• 제13권12호
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• pp.1025-1031
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• 2000

An ultrasonic linear motors consist of a slider and an ultrasonic vibrator which generates an elliptical oscillations. The ultrasonic linear motors mainly consist of an ultrasonic vibrator which generates elliptical oscillations. The ultrasonic linear motor fabricated in this paper was the use of the 1st longitudinal(L1) and 4th bending vibrations(B4). In order to low driving voltage and improve the life time of the ultrasonic motor, we used stacked piezoceramics. Stacked piezoceramics are adhered to aluminum elastic material. The finite element method was used to optimize dimension of ultrasonic vibrator and direction of vibratory displacement. As a result of estimating the characteristics of the ultrasonic linear motor, no-load velocity was 0.204[m/s] when applied voltage was 70[ $V_{rms}$] in resonance frequency.y.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권1호
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• pp.28-37
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• 2017

Purpose: This paper proposes a procedure that may infer and identify interaction failures in a module. Methods: In design FMEA, we defined an interaction model between components and proposed a method for selecting a single component by using the standard specification classification table and four methods for choosing the related components. We also introduced the function tree for function and requirement characteristic analysis and proposed utilization of standard stress lists and 1st and 2nd stress analysis tables to determine the effect the stress analysis has on interactions. Finally, the interaction mechanism diagram was proposed and used to infer the failure mechanism. Process FMEA also established procedures in a similar way. Results: We established a procedure for predicting the failure mode due to interaction between components based on Company A's multi-step FMEA procedure. Conclusion: By applying the proposed interaction FMEA procedure to the development model, we were able to confirm the effect of the new derivation on the failure mode of interaction, which was not predicted by the existing FMEA.

• 대한기계학회논문집
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• 제16권10호
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• pp.1900-1907
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• 1992

본 연구에서는 원형평판의 경계조건을 일부분은 고정단으로 일부분은 자유단 으로 구성하여 자유단각 .alpha.(Fig.4 참조)를 0˚, 30˚, 60˚, 90˚, 120˚, 150˚, 180˚로 변화시킴에 따른 진동모드를 시간평균 홀로그래픽 간섭계(time-average holographic interferometry)를 이용해 분석하고 자유단의 변화에 따른 고유진동수의 비를 비교하였고, 레이저 도플러 유속계(LDV)를 변형한 레이저 도플러 진동계(laser doppler vibrometer)로 원형평판의 진동변위와 시간평균 홀로그래픽 간섭계로 구한 진 동변위를 비교하였다.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.329-332
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• 2012

Background Ankyloglossia or tongue-tie is a congenital anomaly characterized by an abnormally short lingual frenum. Its prevalence in the newborn population is approximately 4%. Its mode of inheritance has been studied in some articles, but no conclusion has been established. Also, no relevant report has been published in Korea. This study was conducted to elucidate the genetic inheritance of ankyloglossia via pedigree analysis. Methods In this study, 149 patients with no other congenital anomaly who underwent frenuloplasty between March 2001 and March 2010 were studied. Pedigrees were made via pre- or post-operative history taking, and patients with uncertain histories were excluded. In the patient group that showed a hereditary nature, the male-to-female ratio, inheritance rate, and pattern of inheritance were investigated. Results One hundred (67.11%) of the patients were male and 49 (32.89%) were female (male-female ratio=2.04:1). Ninety-one (61.07%) patients reported no other relative with ankyloglossia, and 58 (38.93%) patients had a relative with this disease. The inheritance rate was 20.69% in the 58 cases with a hereditary nature. In the group with no family history of ankyloglossia, the male-female ratio was 3.79:1, which significantly differed from that of the group with a family history of ankyloglossia. X-chromosome mediated inheritance and variation in the gene expression was revealed in the pedigree drawn for the groups with hereditary ankyloglossia. Conclusions Ankyloglossia has a significant hereditary nature. Our data suggest X-linked inheritance. This study with 149 patients, the first in Korea, showed X-linked inheritance in patients with a sole anomaly.

• Investigative Magnetic Resonance Imaging
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• 제4권2호
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• pp.94-99
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• 2000

목적 : 국한적 수분억제 생체내 양성자 자기공명분광학을 사용하여 만성 알코을 중독자와 정상 건강인의 뇌대사물질의 비율을 비교평가하였다. 대상 및 방법 : 만성 알코을 중독자 10명,정상 건강인 10명의 좌측 소뇌와 basal ganglia의 관심부위 $2{\times}2{\times}2{\;}\textrm{cm}^3$를 각각 선택하여 STEAM펄스시퀀스를 이용하였다 Creatine (Cr)을 기준으로 Marquart알고리즘을 이용하여 각 대사물질의 비율을 산출하였다. 결과 만성 알코을 중독자의 특징적인 소견은 정상인과 비교하여 볼 때 N-acetyl aspartate (NAA)/Cr비율이 감소하였다. 그러나 Choline (Cho)/Cr등 다른 대사비율은 정상인과 유이한 차이를 발견할수 없었다. NAA/Cr비율은 임상평가와 상당한 상호관계가 있는 것으로 나타났다. 결론 : 본 예비실험 결과는 만성 알코을 중독자의 NAA/Cr의 비율 감소를 토대로 환자 소뇌의 신경세포 소실을 추정할 수 있었다. NAA/Cr비율은 향후 만성 알코을 중독자의 임상평가를 추정할수 있는 대사표준으로 사용될 수 있음을 시사해주고 있다. 따라서 생체내 양성자 자기공명분광법은 양성자 비율을 토대로 만성 알코을 중독자의 임상평가에 유용한 방법으로 사용될 수 있으리라 사료된다.