Numerical analysis has been carried out to predict the thermal characteristics for a LED lens in mold core system. These thermal characteristics inside the lens are largely affected by geometry, material, and initial conditions of the mold core and lens system. Local temperature and heat flux variation inside the lens are compared for several initial temperatures. Maximum temperature inside the lens was decreased rapidly from the beginning of cooling process up to about 10 seconds. There was also large variation of the heat flux at the upper and lower surfaces of the lens with initial temperature distribution. And the heat flux from the thin lower surface of the lens was relatively higher than the opposite-side thick region. In addition, overall heat transfer rate from the lens through the mold core has similar transient distribution from the beginning. These results can be applied as basic heat transfer data for the LED lens design and manufacturing process in the mold core system.

The purpose of this study was to establish reliability and validity of the Northwick Park Neck Pain Questionnaire (NPQ) translated into Korean for neck pain patients. Sixty-two subjects (35 males, 27 females) with neck pain enrolled in the study. They completed a standardized self-administered questionnaire that included pain intensity, sleeping, sensory at night, duration of symptoms, carrying, reading and watching television, working, social activities, and driving. Reliability was determined by intraclass correlation coefficient (ICC) and Cronbach's alpha by internal consistency. Validity was examined by correlating the NPQ scores to the Visual Analog Scale (VAS) score. Test-retest reliability of the translated versions of the NPQ was good ICC(2,1)=.83 (95%CI=.85~.95). Cronbach's alpha value for NPQ was found to be .87 and this was statistically significant (p<.05). The criterion-related validity coefficients was .75 (p<.01). We concluded that the Korean version NPQ was shown to be a reliable and valid instrument for the assessment of neck pain.

This study compared the effect of therapeutic exercise with conservative treatment in women with chronic neck pain. Subjects were allocated to control, neck isometric exercise, and cervical stabilization exercise groups consisting of 29, 32, and 31 patients, respectively. The conservative treatment for the control group consisted of hot packs, ultrasound, interferential current therapy, and intermittent cervical traction. The neck isometric exercise group performed a neck isometric exercise and the cervical stabilization exercise group performed a cervical stabilization exercise. To compare the three groups, the levels of perceived pain, neck disability, and psychological depression were assessed on admission, at discharge, and one month after discharge. On admission and at discharge, the pain and neck disability scores did not differ significantly among the groups. However, one month after discharge, both the neck isometric and cervical stabilization exercise groups had significantly improved perceived pain levels as compared to control (p<.05). The improvement in the degree of neck disability was most significant in the cervical stabilization exercise group (p<.05). On comparing the changes in the variables at the three assessments for each group, there was a significant difference between the control and cervical stabilization exercise groups (p<.05). The findings indicate that therapeutic exercises, especially cervical stabilization exercises, are more effective for improving pain and neck disability than conservative treatment.

The self-report measure is a useful tool for evaluating self-recognized disability and difficulty in daily living activities. Although many studies and clinics used the Neck Pain and Disability Scale (NPDS) for measuring neck pain and functional impairment, there has not been much adaptation of this for use with Korean patients. The purpose of this study was to establish the reliability and validity of NPDS among Korean neck pain patients. Fifty-five subjects (32 males, 23 females) with neck pain enrolled in this study. They completed standardized self-administered questionnaires. The NPDS measures pain intensity; its interference with vocational, emotional, recreational, social, and functional aspects of living; and the presence and extent of associated factors. Reliability was determined by the intraclass correlation coefficient (ICC) and Cronbach's alpha for internal consistency. Validity was examined by correlating the NPDS scores to the Visual Analog Scale (VAS) score. The test-retest reliability of the translated versions of the NPDS was good ICC (2,1)=.86 (95%CI .76~.92). Cronbach's alpha value for NPDS was found to be .93, and this was statistically significant (p<.05). The criterion-related validity coefficient was .79 (p<.Oll. We conclude that the Korean version of NPDS has been shown to be a reliable and valid instrument for the assessment of neck pain. Successful linguistic and cultural translation will admit appropriate cross-cultural comparison for clinical analysis. Therefore, this study can be expected to be used as an adequate evaluation scale for neck pain related studies and treatments.

The purpose of this study was to determine reliability and validity of the Neck Disability Index (NDI) now in use for the first time in neck pain patients of Korea. Fifty subjects (26 males and24 female) with neck pain enrolled in the study. They completed a standardized self-administered questionnaire that include pain intensity, personal care, lifting, reading, headaches, concentration, work, driving, sleeping and recreation. Reliability was determined by intra-class correlation coefficient (ICC) and Cronbach's alpha by internal consistency. Validity was examined by correlating the NDI scores to the Visual Analog Scale (VAS) score. The Test-retest reliability of the translated versions of the NDI was good ICC (2,1) = .90 (95%CI .85 .95). Cronbach's alpha value for NDI was found to be .95 and this was statistically significant (p<.05). The criterion-related validity coefficients was .72 (p<.01). We conclude that the Korean version of NDI has shown to be a reliable and valid instrument for the assessment of neck pain.