Earticle

CZTS 태양전지는 Cu, Zn, Sn, Se, S으로 구성된 흡수층을 사용하는 박막 태양전지로, In, Ga이 사용되는 CIGS 태양전지보다 저렴하며 Pb, Cd이 사용된 페로브스카이트, CdTe 태양전지보다 친환경적이다. 본 연구에서 우리는 유연기판인 Mo foil 위에 제작된 유연 CZTS 태양전지를 지정된 곡률만큼 휘게 하는 bending test를 진행 하였다. 태양전지에 압축응력이 가해지는 inner benidng과 인장응력이 가해지는 outer bending의 방향에서 실험은 진행되었으며, 50 mmR의 곡률 반경으로 진행된 1,000 회의 굽힘 횟수 동안 태양전지의 효율은 최고 12.7%까지 감소하였으며, 두 방향 모두에서 효율 감소의 가장 큰 원인은 병렬저항의 큰 감소로 나타났다.

The CZTS solar cell is a thin film solar cell using an absorption layer composed of Cu, Zn, Sn, Se, and S, and is cheaper than a CIGS solar cell using In and Ga and more eco-friendly than a perovskite and CdTe solar cell using Pb and Cd. In this study, we conducted a bending test for flexible CZTS solar cells. Experiments were conducted in the direction of inner benidng with compressive stress and outer bending with tensile stress, and during the number of bending 1,000 times with a radius of curvature of 50 mmR, the efficiency of the solar cell decreased by up to 12.7%, and the biggest cause of efficiency reduction in both directions was a large decrease in parallel resistance.

The most important role of air defense system is to attack the air target of enemy to defend the important military unit or facilities. In order to attack the target as soon as it is detected, fast and precise fire signal transfer using the fire control stick is very important. However, it was found that firing is not conducted in the test for fire control stick. In order to find the reason of such problem and improve life cycle of fire control stick, the test was conducted and it was found that chattering occurred and this led to malfunction of signal transfer from control stick to fire control unit of air defense system. In order to draw resolution for this problem, two contact plate made of beryllium copper is suggested to add to the control stick to enhance the contact and reduce chattering effect. The four fire switch prototypes were tested for 100,000 times and it showed its reliability of use.

Background Wearable gait analysis devices are increasingly used in clinical practice to evaluate spatiotemporal gait parameters. StepLab is one such device; however, research on its reliability for gait analysis remains limited. Purpose This study aimed to evaluate the test?retest reliability of spatiotemporal gait parameters measured using the StepLab IMU-based wearable device in healthy young adults. Study design Cross-sectional study Methods Forty healthy participants (20 females and 20 males; mean age 21.7±3.44 years) completed three 10-meter walk trials at a comfortable, self-selected pace. The same protocol was repeated one week later to assess measurement consistency. Gait parameters, including gait speed, swing duration, stance duration, cycle time, cadence, stride length, and step length, were analyzed. Test?retest reliability was determined using intraclass correlation coefficients (ICC 3,2). Bland?Altman analysis and standard error of measurement (SEM) were additionally calculated. Results All spatiotemporal gait parameters demonstrated good to excellent test?retest reliability, with ICC values ranging from 0.84 to 0.99 and small SEM estimates across variables. Bland?Altman analysis revealed minimal mean differences and narrow limits of agreement, indicating high measurement consistency between sessions. Conclusions The StepLab device demonstrated good to excellent test?retest reliability for spatiotemporal gait parameters in healthy young adults under controlled indoor conditions. However, caution is warranted when interpreting these findings due to the homogeneous sample and the short 10-meter walking distance. Future studies should examine reliability in clinical and elderly populations, assess longer walking tasks, and validate StepLab against gold-standard gait analysis systems before broader clinical application.

Objective : Lifestyle is one of the vital determinants for health and quality of life for older adults. This study aimed to assess the psychometric properties of the Yonsei Lifestyle Profile (YLP) in community-dwelling older adults. Methods : The instrument psychometric properties were assessed in a sample of community-dwelling older adults in South Korea. A total of 156 older adults completed the YLP. Internal consistency was analyzed using Cronbach’s alpha (α) reliability coefficient. Test-retest reliability using an Intraclass Correlation Coefficient (ICC) was assessed based on scores attained two weeks apart. Results : Sixty items were developed based on the comprehensive literature review and Delphi studies. The total scale of the YLP was .83, which reflects high internal reliability. The alpha values of the YLP subscales ranged from .80 to .74 for all participants. Regarding the test-retest reliability, the ICC was .97 for the total scores of the YLP, ranging from poor to good (.47~.99) for the YLP subscales. Thus, it was confirmed that the YLP has adequate test-retest reliability statistics. Conclusions : The YLP developed to measure the multidimensional lifestyle factors of older adults is a valid instrument to apply in community-dwelling older adults. The YLP questionnaire can be used in clinical practice when health-care practitioners evaluate their client’s lifestyle.

Objective To evaluate the test-retest reliability of supraspinatus cross-sectional area measurement by ultrasonography. Method Both shoulders of 11 normal subjects (22 shoulders in total) were included in this study. The supraspinatus muscle was examined with the arm alongside the body in the coronal oblique and sagittal oblique planes. Th e occupational ratio of the supraspinatus fossa was measured. To calculate the occupational ratio, the Y view of MRI was reproduced with sonography by locating the suprascapular notch in the coronal oblique plane (in the plane of the scapula) and then rotating the transducer 90˚ to that plane. Th e cross-sectional area was measured using the tracing and ellipse tool. Th e second measurement was performed 7 days after the initial measurement. Results The Pearson correlation coefficient and intraclass correlation coefficient between the first and the second occupational ratio measurements were 0.43 and 0.44, respectively, for the tracing method, and 0.53 and 0.47, respectively, for the ellipsoidal method. The difference between the first and second occupational ratio measurement was 4.1±3.9% (0.1-13.2%) for the tracing method, and 4.5±3.4% (0.01-10.5%) for the ellipsoidal method. Th e maximum difference was 13.2%. Th e occupational ratio was 86.2±5.3% (70.6-95.8%) for the tracing method and 85.0±5.2% (69.3-96.1%) for the ellipsoidal method. Conclusion Supraspinatus occupational ratio by sonography is a low to moderately reliable intrarater method. However, the maximum diff erence was not signifi cant. Th e main reason for its low to moderate reliability was the narrow value range. Therefore, the study method should be re-evaluated in stroke patients and in patients with rotator cuff disease. Knowledge of the anatomy is a prerequisite to attain intrarater reliability.

ABSTRACT Background The strength of iliopsoas muscle is frequently measured to evaluate the performance of hip flexion in the clinical setting. However, little research into the test- retest reliability of iliopsoas muscle strength in subjects with lumbar extension syndrome (LES) in supine position has been reported. Purpose The purpose was to compare the test-retest reliability of iliopsoas strength measurement in supine position with break and make test in subjects with LES. The iliopsoas muscle is very important in the hip joint structures. The reliable measurement is essential to evaluate the performance of hip flexion. Study design Reliability study. Methods Twenty subjects were enrolled in this study. The strength of iliopsoas muscle was measured in supine position, with using a smart KEMA tensiometer system for make test, using a hand held dynamometer for break test. The intra class correlation coefficients (ICC 3, 1) were used to determine test-retest reliability of iliopsoas muscle strength. Results Test-retest reliability of iliopsoas muscle strength measurements in make test was significantly greater compared with break test (p<0.05). The value of ICC with make test was greater than make test (0.86 for make test, 0.71 for break test). Additionally, the coefficients of variation (4.5% for make test, 18.3% for break test) was better in the supine position with make test. Conclusions The measurement of iliopsoas muscle strength in make test can be more reliable than break test in subjects with LES in supine position. The make test in supine position can be recommended for reliable measurement of iliopsoas muscle in subjects with LES.

ABSTRACT Background Hamstring tightness is a major cause of low back pain (LBP). The active knee extension (AKE) test is frequently used to measure hamstring tightness in supine-positioned subjects. In patients with musculoskeletal pain, it is important to maintain the axis of rotation for accurate range of motion assessment. Purpose The purpose of this study was to investigate the intrarater test-retest reliability of an AKE test with belt-guided inferior gliding of the hip, which was designed to minimize excessive anterior-superior gliding of the hip in LBP patients with hamstring tightness. We also compared the range of AKE with versus without inferior gliding of the hip in this study population. Study design Reliability study. Methods Thirty-eight patients with LBP and hamstring tightness were recruited to this study. Hamstring tightness was measured in a supine AKE test, with and without inferior gliding of the hip, using the Smart KEMA device. Test?retest reliability was assessed by the intraclass correlation coefficient (ICC). Significant differences in the range of AKE between the groups were detected using a paired sample t-test. Results The hamstring flexibility tests with and without inferior gliding of the hip exhibited good to excellent test-retest reliability (ICC=0.89 for both). The range of AKE with inferior gliding of the hip was significantly less than that of AKE without inferior gliding of the hip. Conclusions Assessment of hamstring flexibility via an AKE test with inferior gliding of the hip is reliable when applied to patients with LBP; the range of AKE was lower in this test compared to those that do not incorporate inferior gliding of the hip.

Background Shortened levator scapula (LS) is a major cause of neck and shoulder pain and reduced motor function. Therefore, measuring LS muscle length is a key element in evaluating patients with shoulder dysfunction. Purpose The purpose of this study was to evaluate the intra- and inter-rater reliability of a newly designed levator scapular length test (LSLT). Study design Intra- and inter-tester repeated measures. Methods We recruited 28 participants in this study. Subjects were divided into two groups: normal scapula length and shortened scapula length. The LS index (LSI) and LSLT were applied twice by one examiner and once by a different examiner. The intraclass correlation coefficient was used to assess intra- and inter-rater reliability of the LSI and LSLT. Pearson’s correlation coefficient was used to evaluate the correlation between the tests. Results The intra-rater reliability scores of LSI and LSLT were 0.95 and 0.98, and the inter-rater test reliability scores were 0.96 and 0.98, respectively. The correlation coefficient was 0.63, indicating a moderate relationship between tests. Conclusions These findings suggest that LSLT is a reliable method for measuring LS length in clinical practice.

Background A short extensor digitorum longus (EDL) is associated with limited ankle dorsiflex-ion, toe deformities (such as hammer toe and claw toe), and diabetic plantar ulcers. Therefore, measurement of EDL is important for the evaluation of patients with foot dysfunction. Purpose The aim of this study was to evaluate the intra- and inter-rater reliability of the muscle length test for EDL. Study design Repeated measures for intra- and inter-test reliability. Methods Thirty participants were recruited. Two physical therapists evaluated EDL length based on the difference in passive ankle plantar flexion angle between relaxed and flexed toe positions. Each examiner measured it in each participant three times. The intraclass correlation coefficient was used to assess the intra- and inter-rater reliability of the muscle length test for EDL. Results The intra- and inter-rater reliability values were 0.83 and 0.75, respectively. The standard error of measurement was 1.93° and the minimum detectable change was 5.35°. Conclusions The muscle length test is a reliable method for measuring EDL length in clinical practice.

Background: In clinical setting, the cervical range of motion (ROM) is commonly used to identify movement impairment and assess function of neck. For assessing and improving the cervical ROM and proprioception, we developed the device using the digital goniometer with inertial measurement unit. Purpose: The purpose of this study was to determine the intra-rater reliability and validity of cervical ROM measurement using the digital goniometer and Cervcial Range-of-Motion (CROM) device. Study design: Cross-sectional study. Methods: Fifteen healthy subjects without neck pain were participated in this study. The measure-ments of flexion, extension, side-bending (right/left), and rotation (right/left) were made with CROM device and digital goniometer in sitting. Two trials of cervical ROM measurement (6 movements) were performed for each subject. Validity and intra-rater reliability were determined using Spearman correlation coefficient and intra-class correlation coefficient (ICC3,1) for digital goniometer and CROM, respectively. Results: The digital goniometer demonstrated good (Spearman ρ=0.88?0.98, p<0.01) validity for CROM. The intra-rater reliability was demonstrated for cervical flexion (ICC3,1=0.99), extension (ICC3,1=0.99), right (ICC3,1=0.99) and left (ICC3,1=0.99) lateral flexion, right (ICC3,1=0.99) and left (ICC3,1=0.99) rotation. Conclusions: The digital goniometer was found to be reliable and valid for measuring cervical ROM in three planes for normal subjects. However, before using the digital goniometer as an outcome measure in clinical settings, studies should be performed on subjects with neck pain.

Objective To determine the reliability and validity of hand-held dynamometer (HHD) depending on its fixation in measuring isometric knee extensor strength by comparing the results with an isokinetic dynamometer.Methods Twenty-seven healthy female volunteers participated in this study. The subjects were tested in seated and supine position using three measurement methods: isometric knee extension by isokinetic dynamometer, non-fixed HHD, and fixed HHD. During the measurement, the knee joints of subjects were fixed at a 35o angle from the extended position. The fixed HHD measurement was conducted with the HHD fixed to distal tibia with a Velcro strap; non-fixed HHD was performed with a hand-held method without Velcro fixation. All the measurements were repeated three times and among them, the maximum values of peak torque were used for the analysis. Results The data from the fixed HHD method showed higher validity than the non-fixed method compared with the results of the isokinetic dynamometer. Pearson correlation coefficients (r) between fixed HHD and isokinetic dynamometer method were statistically significant (supine-right: r=0.806, p<0.05; seating-right: r=0.473, p<0.05; supine-left: r=0.524, p<0.05), whereas Pearson correlation coefficients between non-fixed dynamometer and isokinetic dynamometer methods were not statistically significant, except for the result of the supine position of the left leg (r=0.384, p<0.05). Both fixed and non-fixed HHD methods showed excellent inter-rater reliability. However, the fixed HHD method showed a higher reliability than the non-fixed HHD method by considering the intraclass correlation coefficient (fixed HHD, 0.952-0.984; non-fixed HHD, 0.940-0.963). Conclusion Fixation of HHD during measurement in the supine position increases the reliability and validity in measuring the quadriceps strength.

Objective To develop and standardize the Limb and Oral Apraxia Test (LOAT) for Korean patients and investigate its reliability, validity, and clinical usefulness for patients with stroke. Methods We developed the LOAT according to a cognitive neuropsychological model of limb and oral praxis. The test included meaningless, intransitive, transitive, and oral praxis composed of 72 items (56 items on limb praxis and 16 items on oral praxis; maximum score 216). We standardized the LOAT in a nationwide sample of 324 healthy adults. Intra-rater and inter-rater reliability and concurrent validity tests were performed in patients with stroke. We prospectively applied the LOAT in 80 patients and analyzed the incidence of apraxia. We also compared the clinical characteristics between the apraxia and non-apraxia groups. Results The internal consistency was high (Cronbach’s alpha=0.952). The inter-rater and intra-rater reliability and concurrent validity were also high (r=0.924?0.992, 0.961?0.999, and 0.830, respectively; p<0.001). The mean total, limb, and oral scores were not significantly different according to age and education (p>0.05). Among the 80 patients with stroke, 19 (23.8%) had limb apraxia and 21 (26.3%) had oral apraxia. Left hemispheric lesions and aphasia were significantly more frequently observed in the limb/oral apraxia group than in the non-apraxia group (p<0.001). Conclusion The LOAT is a newly developed comprehensive test for limb and oral apraxia for Korean patients with stroke. It has high internal consistency, reliability, and validity and is a useful apraxia test for patients with stroke.

Objective : This study aimed to verify the validity and reliability of the Upper Extremity Performance Test for the Elderly (TEMPA) by modifying its items 새 exhibit cultural differences. Methods : This study included 171 healthy adults and older adults and 41 individuals with impaired upper extremity function. Content validity, discriminant validity, test-retest reliability, and inter-rater reliability were analyzed. Results : The following items, exhibiting cultural differences, were modified: “open a lock and take the top off a pillbox”and“write and affix a postage stamp.” The discriminant validity results indicated that participants with normal upper extremity function performed better than those with impaired in the upper extremity function (p<.001). The test-retest reliability of the execution speed (intraclass correlation coefficient; ICC) was .71–.94, functional rating (kappa) was 1.0, and task analysis (ICC) was 1.0. The inter-rater reliability of the speed of execution was 1.0, functional rating was .79–1.0, and task analysis was .94–1.0. Conclusion : TEMPA has moderate to high level of reliability and is an assessment tool that can clearly distinguish individuals with upper extremity impairment from those without impairment

The purpose was to examine the test-retest reliability of the Rolimeter measurement procedure in the acute time phase, following a substan-tial knee trauma. In total, 15 participants with acute knee trauma were examined by one single observer at three different time-points with the Rolimeter using a maximum force. The selected time-points were: baseline (0–7 days after the trauma), midpoint (3–4 weeks after the trau-ma), and endpoint (3–4 weeks after the trauma). The anterior-posterior displacement was recorded where the endpoint evaluation was used as the reference value. The mean anterior laxity scores remained con-stant over the measurement time-points for both knees, with an anterior laxity that was 2.7 mm higher (on average) in the injured than the nonin-jured knee (9.5 mm vs. 6.8 mm). The mean difference (i.e., bias) between laxity scores, for the injured knee, measured at endpoint versus base-line was 0.2±1.0 mm and -0.2±1.1 mm when measured at endpoint ver-sus midpoint, with average typical errors of 0.7 and 0.8 mm and intra-class correlations that were very strong (both r=~0.93). For the same comparisons on the noninjured knee, systematic bias was close to zero (0.1±0.3 and -0.1±0.3 mm, respectively), and both the intra-class cor-relations were almost perfect (r=~0.99). The current study implicates that repeated Rolimeter measurements are relatively reliable for quanti-fying anterior knee laxity during the acute time-phases following knee trauma. Hence, the Rolimeter, in combination with manual tests, seems to be a valuable tool for identifying anterior cruciate ligament injuries.

This study presents a comprehensive procedure for the low cycle fatigue test of ultrasonically welded (UW) coated conductor (CC) lap-joints. The entire process is examined in detail, from the robust fabrication of the UW REBCO CC joints to the reliability testing under a low number of repeated cycle fatigue conditions. A continuous Ic measurement system enables real-time monitoring of Ic variations throughout the fatigue tests. The study aims to provide a step-by-step procedure that involves joint fabrication, electromechanical property (EMP) tests under uniaxial tension for stress level determination, and subsequent low-cycle fatigue tests. The joints are fabricated using a hybrid method that combines UW with adding In-Sn soldering, achieving a flux-free hybrid welding approach (UW-HW flux-free). The selected conditions for the low cycle fatigue tests include a stress ratio of R=0.1 and a frequency of 0.02 Hz. The results reveal some insights into the fatigue behavior, irreversible changes, and cumulative damage in the CC joints.

Purpose: The purpose of this methodological study was to examine the validity and reliability of a translated Korean version of The Oncology Patients’ Perception of the Quality of Nursing Care Scale. Methods: The translated scale was pilot tested and then administered to 360 patients with cancer. Exploratory and confirmatory factor analyses were utilized to assess the factor structure. Internal consistency reliability was determined using coefficient ?. Results: Two of the 40 items were deleted with a principal component method of exploratory factor analysis becausethey did not meet the factor-loading criterion. The 38 items were again analyzed and, four factors were validated (KMO=.96, Bartlett x2=10809.81, df=780, p<.001). The four factors accounted for 60.9% of the variance. Factor loadings of the scale on the four subscales ranged from .65 to .91. The scale showed reliable internal consistency with a Cronbach's ?, total 38 items (?=.96) in four subscales: individualization (18 items, ?=.96), proficiency (10, .91), responsiveness (7, .90), and coordination (3, .80). Conclusion: The findings of this study demonstrate that the scale has satisfactory construct validity and reliability to measure quality of cancer nursing care from the patient’s perspective in Korea.

이 연구는 다수의 소검사로 이루어진 검사에서의 요인구조 추출 및 신뢰도에 대한 것이다. 여기서 소검사라고 하면 검사제작, 시행, 또는 채점에서 하나의 단위로 취급되는 문항군으로서 이 글에서는 제작단계에 중점을 둔다. 제작시 형태로 보면, 모의(시뮬레이션)과제, 시나리오 또는 큰 문단이 있고 그 아래 한 묶음의 채점항목 또는 문항군이 있는 형식을 의미한다. 이러한 검사의 자료에서는 각 소검사내의 국지적 관련성이 높아지고, 검사 전체로서 측정오차의 독립성 및 국지적 독립성(local independence)이 위배되어 요인분석의 실시 및 신뢰도 산출에 어려움이 있다. 이러한 검사 자료는 과제나 시나리오가 고정효과인지 무선효과인지에 따라 요인해석도 다르고 신뢰도의 정의도 다르다. 요인구조의 추출을 위해서는 제작시 무엇을 잴 것인지의 설계에 기초한 확인적 요인분석이 유용하며 신뢰도의 산출을 위해서는 고전검사이론에서 가정하는 오차의 독립성이 위반되는 것을 허용하며, 나아가 문항간 국지적 의존성까지 감안하는 신뢰도 산출 방식이 필요하다.

When a test comprises of multiple testlets, it is very difficult to estimate factor structure and reliability of the data collected by the test. A testlet is defined by a scenario or passage and response alternatives following it. A testlet-based test suffers difficulties of estimating factor structure because the method factors are confounded with substance factors and of estimating reliability because the measurement errors are not independent and local independence is severely challenged. In the present study, we propose an approach of applying a series of confirmatory factor analysis to analyze the data prepared in the form of multitrait-multimethod data. The approach varies depending on whether the situation effect is fixed or random. In the specification search, we adopt correlated uniqueness model to avoid estimation problems when both trait factor(s) and method factor(s) exist in a model. The final model can be transformed to a correlated uniqueness model or a method factor model depending on whether situation effect is of random effect or fixed effect. In this process, we can estimate item reliability and in turn test reliability.

Objective: To verify the interrater and intrarater reliability of Korean Wolf Motor Function Test (K-WMFT) for assessing upper extremity function after stroke. Method: Twenty patients with chronic hemiparesis after stroke participated in the study. The Wolf Motor Function Test consists of 15 functional tasks. Performances were timed and rated by functional ability scale. The K-WMFT were administered to the subjects by an occupational therapist. All test sessions were videotaped and scored by 2 physiatrists and another occupational therapist to examine interrater reliability. They were reevaluated at a later time by thesame occupational therapist to examine intrarater reliability. Results: Intraclass correlation coefficient of the performance time of K-WMFT was 0.94 and that of the functional ability scale of K-WMFT was 0.99. Intrarater correlation coefficient of the performance time of K-WMFT was 1.00 and that of the functional ability scale of K-WMFT was 0.97. Conclusion: The interrater and intrarater reliability of K- WMFT were verified. K-WMFT can be used as a reliable tool to measure upper extremity function of the stroke patients in Korea.

우리나라는 비약적인 산업기술발전을 통해 선진국 진입을 눈앞에 두고 있지만, 제조 물책임법(PL법) 대응방안 및 고객신뢰성 확보 미흡으로 인해 선진국 진입에 어려움을 겪고 있다. 특히 안정성 및 신뢰성이 확보되지 않은 부품소재의 경우 조립업체의 사용 기피가 생기며 부품소재의 국산화 이후 시장 진출 시 소비자가 최초의 사용자가 되기 를 꺼려한다는 점이 대두 되고 있다. 이는 우리나라의 원천 기술의 수입의존도를 심화 시켜 결국 국가경쟁력 약화를 가져오는 악순환의 반복을 가져오는 원인 되고 있으며, 이를 극복하기 위해서는 신뢰성확보가 시급한 시점이다. 본 논문에서는 신뢰성 확보를 위해 신뢰성 시험의 연구동향을 분석 할 것이며, 이를 통해 신뢰성 향상 및 효과적인 활용방안을 모색 하고자 한다.