• Title/Summary/Keyword: a model validity

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Validity of Inter-Particle Models for the Mass-Transfer Kinetics of a Fin-Tube-Type Adsorption Bed (핀-튜브형 흡착탑 해석시 입자간 물질전달 모델의 타당성 검증)

  • Ahn, Sang Hyeok;Hong, Sang Woo;Kwon, Oh Kyung;Chung, Jae Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.12
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    • pp.660-667
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    • 2013
  • This study presents a numerical investigation of the heat and mass transfer kinetics of a fin-tube-type adsorption bed using a two-dimensional numerical model with silica-gel and water as the adsorbent and refrigerant pair. The performance is strongly affected by the heat and mass transfer in the adsorption bed, but the details of the mass transfer kinetics remain unclear. The validity of inter-particle models used to simulate mass-transfer kinetics were examined, such as a constant pressure model and non-constant pressure model, and the valid ranges of the diffusion ratio for each model are proposed. The COP and SCP have been numerically calculated as the performance indexes according to the diffusion ratio. The constant pressure model, which is commonly used in previous research, was found to be valid only in a limited range of diffusion ratio.

모바일 애플리케이션 마켓(앱스토어)의 수용의도 영향요인에 관한 연구

  • Bae, Jae-Gwon
    • Proceedings of the Korea Database Society Conference
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    • 2010.06a
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    • pp.223-234
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    • 2010
  • This study is aimed at proposing a new research model in which application store intention to acceptance influence factors (i.e.. facilitating condition, mobile computing self-efficacy, service compatibility, and system quality) affect TAM (i.e., perceived usefulness and perceived ease of use) positively, leading to application store intention to acceptance eventually. This study developed a research model to explain the use of Apple's App Store, and collected 228 survey responses from the undergraduate students who had experiences with such application store services as game and personal information management application download. To prove the validity of the proposed research model, PLS analysis is applied with valid 228 questionnaires. By employing PLS technique, the measurement reliability and validity of research variables are tested and the path analysis is conducted to do the hypothesis testing. In brief, the finding of this study suggests that application store intention to acceptance influence factors affect TAM positively, and application store intention to acceptance as well.

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Impact ionization for GaAs using full band monte carlo simulation (Full 밴드 몬테칼로 시뮬레이션을 이용한 GaAs 임팩트이온화에 관한 연구)

  • 정학기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.11
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    • pp.112-119
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    • 1996
  • Impact ionization model in GaAs has been presented by modified keldysh formula with two sets of power exponent of 7.8 and 5.6 in study. Impact ionization rate is derived from fermil's golden rule and ful lenergy band stucture based on empirical pseudopotential method. Impact ionization rates show anisotropic property in low energy region (<3eV), but isotropic in high energy region (3>eV). Full band monte calo simulator is coded for investigating the validity of the GaAs impact ionization model, and validity is checked by comparing impact ionization coefficients with experimental values and ones in anisotropic model. Valley transitions to energy alteration are explained by investigating electron motion in brillouin zone for full band model to electric field variation.

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Validity of the Korean Version of the Schema Mode Inventory (SMI)

  • Song, Younghee;Lee, Eunhee
    • International Journal of Advanced Culture Technology
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    • v.8 no.1
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    • pp.248-256
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    • 2020
  • This study investigated whether the schema modes have validity in Korean adults. We examined the validity and reliability of the Schema Mode Inventory (SMI) in a Korean adult sample (N = 768; Mean age = 22.29 years; range = 19-55 years; 69.3% Males). Psychometric properties, such as factor structure, internal reliability, as well as intercorrelations among subscales were assessed. Confirmatory factor analyses yield satisfying fits for a 61-item Korean Schema Mode Inventory. Thirteen Schema Mode Inventory scales were found to have adequate reliability of the original 14 schema factors. Furthermore, the SMI scales differentiated between depressed and non-depressed participants as theoretically predicted. These findings imply that the SMI is a sound instrument to measure the schema mode model in a Korean setting for assessment prior to schema therapy.

A Validity Study on the Vocabulary Grade Levels Test for Korean Elementary Students

  • Shin, Yousun
    • English Language & Literature Teaching
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    • v.18 no.2
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    • pp.125-147
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    • 2012
  • The primary goal of the study was to provide some preliminary validity evidence for the Vocabulary Grade Levels Test (Busan Metropolitan City Office of Education, 2009), which is designed to measure the receptive vocabulary knowledge of learners in L2. For the purpose of the current study, 327 participants at the elementary school participated in the study and were asked to take two different vocabulary tests. Namely, a Vocabulary Size Test (Nation, 2001) and a Vocabulary Grade Levels Test. The data were analyzed using correlation in order to discover the relationship between these two types of tests. Following this, the Rasch analysis was conducted to examine the reliability and validity of the measurement in question. The data analysis showed that both grade separation reliability and item separation reliability were high, indicating that the Vocabulary Grade Levels Test well discriminates learners with a wide range of proficiency levels. The findings of the study are discussed, along with further improvements in order to ascertain the validity of this particular vocabulary test.

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Reliability and Validity of the Korean Version of the Coping and Adaptation Processing Scale-Short-Form in Cancer Patients

  • Song, Chi Eun;Kim, Hye Young;So, Hyang Sook;Kim, Hyun Kyung
    • Journal of Korean Academy of Nursing
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    • v.48 no.3
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    • pp.375-388
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    • 2018
  • Purpose: This study was conducted to assess the reliability and validity of the Korean version of the Coping and Adaptation Processing Scale-Short- Form in patients with cancer. Methods: The original scale was translated into Korean using Brislin's translation model. The Korean Short-Form and the Functional Assessment Cancer Therapy-General were administered to 164 Korean patients with cancer using convenience sampling method. The collected data were analyzed using SPSS 23.0 and AMOS 23.0. Construct validity, criterion validity, test-retest reliability, and internal consistency reliability of the Korean Coping and Adaptation Processing Scale-Short-Form were evaluated. Results: Exploratory factor analysis supported the construct validity with a four-factor solution that explained 60.6% of the total variance. Factor loadings of the 15 items on the four subscales ranged .52~.86. The four-subscale model was validated by confirmatory factor analysis (Normed ${\chi}^2=1.38$ (p=.013), GFI=.92, SRMR=.02, RMSEA=.05, TLI=.94, and CFI=.95), and criterion validity was demonstrated with the Functional Assessment Cancer Therapy-General. Cronbach's alpha for internal consistency of the total scale was .83 and ranged .68~.81 for all subscales, demonstrating sufficient test-retest reliability. Conclusion: The Korean version showed satisfactory construct and criterion validity, as well as internal consistency and test-retest reliability.

Investigation of the Validity of the Image Model for the Analysis of Spherical Wave Reflection

  • Suh, Jin-Sung;Cheung, Wan-Sup
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.3E
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    • pp.27-34
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    • 1998
  • The validity of the image model is investigated both analytically and experimentally in a half space with an infinite single reflecting surface present. This paper exploits the Sommerfeld integral that represents the exact solution for the reflected field in the half space. The solution is shown to be obtained by direct numerical integration which yields more accurate and stable results. The predicted results from the image model are compared to those from the direct numerical integration of the Sommerfeld integral. It is also experimentally demonstrated that the image model gives acceptably accurate results. It is of significance that this paper reveals analytical and experimental validation of using the image model except near-grazing incidence.

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An improved kirchhoff approximation for radar scattering from rough surfaces (거친 표면 레이다 산란 해석을 위한 개선된 Kirchhoff 근사 방법)

  • Oh, Yisok
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.1
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    • pp.45-52
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    • 1995
  • A new Kirchhoff approximation(KA) method was proposed for microwave scttering from randomly rough surfaces. Using the spectral representation of delta function and its sifting theorem, a new KA was formulated directly without any further approximation, and this formulated was used to compute exact backscttering coefficients. The validity of the KA was verified by a numerical method, and this new KA technique was used to evaluate the existing approximated KkA methods; i.t., the zeroth-order and the first-order approximated physical optics(PO) models. It was shown that the first-order approximated PO model has small error than the zeroth-order approximated PO model at low incidence angles and the opposite happens at higher incidence angles. This new KA model can be used to compute exact scattering coefficients in the validity regions of KA and to evaluate other theoretical and numerical models for scattering from randomly rough surfaces.

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Adapting the Community Readiness Model and Validating a Community Readiness Tool for Childhood Obesity Prevention Programs in Iran

  • Mahdieh Niknam;Nasrin Omidvar;Parisa Amiri;Hassan Eini-Zinab;Naser Kalantari
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.1
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    • pp.77-87
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    • 2023
  • Objectives: It is critical to assess community readiness (CR) when implementing childhood obesity prevention programs to ensure their eventual success and sustainability. Multiple tools have been developed based on various conceptions of readiness. One of the most widely used and flexible tools is based on the community readiness model (CRM). This study aimed to adapt the CRM and assess the validity of a community readiness tool (CRT) for childhood obesity prevention programs in Iran. Methods: A Delphi study that included 26 individuals with expertise in 8 different subject areas was conducted to adapt the CRM into a theoretical framework for developing a CRT. After linguistic validation was conducted for a 35-question CR interview guide, the modified interview guide was evaluated for its content and face validity. The quantitative and qualitative analyses were performed using Stata version 13 and MAXQDA 2010, respectively. Results: The Delphi panelists confirmed the necessity/appropriateness and adequacy of all 6 CRM dimensions. The Persian version of the interview guide was then modified based on the qualitative results of the Delphi study, and 2 more questions were added to the community climate dimension of the original CRT. All questions in the modified version had acceptable content and face validity. The final CR interview guide included 37 questions across 6 CRM dimensions. Conclusions: By adapting the CRM and confirming linguistic, content, and face validity, the present study devised a CRT for childhood obesity prevention programs that can be used in relevant studies in Iran.

Validation Study of the Korean Version of the Jefferson Scale of Empathy-Health Professions Students for Measuring Empathy in Undergraduate Nursing Students (간호대학생 대상 한국판 의료계열 학생용 제퍼슨 공감 척도의 신뢰도 및 타당도 검증)

  • Kim, Jisoon;Ahn, Sukhee
    • The Journal of Korean Academic Society of Nursing Education
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    • v.24 no.3
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    • pp.259-268
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    • 2018
  • Purpose: This study was to validate the Korean version of the Jefferson Scale of Empathy-Health Professions Students (K-JSE-HPS) in undergraduate nursing students. Methods: With a survey design, a total of 293 junior and senior nursing students were recruited and data were collected using a self-administered study questionnaire to measure their levels of empathy use the K-JSE-HPS. Using SPSS/WIN 22.0 and AMOS 22.0, data analysis was conducted with confirmatory factor analysis, criterion validity, and reliability. Results: For construct validity, confirmatory factor analysis showed an acceptable model fit (Goodness of Fit Index was 0.88) along with confirming convergent and discriminant validity (construct reliability was 0.70). For criterion validity, the scale was significantly related with the Interpersonal Reaction Index. For reliability, Cronbach's ${\alpha}$ coefficient for the scale was 0.87 and for the subscales were 0.84, 0.78, and 0.69, respectively. Conclusion: The findings show satisfactory construct and criterion validity and reliability of the Korean version of the JSE-HPS for measuring empathy in undergraduate nursing students.