• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2433-2442
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• 2014

In this paper, an efficiency grade standard for imaging equipments using electrophotograph printing such as a printer, copier, fax, and MFD (Multi Function Device) is studied. By emphasizing domestic standby power reduction program's problem, and proposing the necessity of efficiency management, the efficiency standard is developed by reliable data registered in domestic standby power reducing program. To find an efficiency indication for grade, correlation analysis is used and as a result, printing speed has the biggest correlation coefficient. By applying the efficiency indication for grade, the proposed certification standard is established in 1st to 5th level products and super-high-efficiency product (energy frontier) which is better than 1st to 5th level products. If these efficiency standards are chosen by government policies, it is expected to save 65 billion won reduction of energy cost per year.

• Journal of Korean Neurosurgical Society
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• v.30 no.7
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• pp.842-848
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• 2001

Objectives : The mortality rate of subarachnoid hemorrhage(SAH) has been reduced recently due to refinement of microsurgical technique and improved perioperative management. Also, many survivors of SAH show excellent neurological recoveries. However, we found that a high proportion of the survivors do not fully regain their premorbid status in cognitive and memory function. Object of this study is to evaluate which factors might influence on cognitive and memory impairment in ruptured aneurysmal SAH patients. Methods : In this prospective study, a series of 66 patients with aneurysmal subarachnoid hemorrhage(SAH) from 1996 to 1998, most of whom had a "good" or "fair" neurological outcome, were assessed with various tests of cognition and memory function. All patients underwent clipping operation by pterional approach. Right side approach was performed in 16 case and left 21 cases. K-WAIS(Korean-Wechsler Adult Intelligence Scale) was used as method of cognition and memory function test. The time interval between SAH and assessment varied between 4 months and 8 months, averaging 6.2 months. Statistical analyses were carried out for each test score to see whether aneurysm site(A-com : non A-com), route of approach, age and sex, vasospasm, Hunt-Hess grade and Fisher CT group at admission, Glasgow Outcome Scale(GOS) at discharge affect cognitive and memory function. Results : Aneurysm site was not shown to be associated with performance on any test, and the initial grade (Hunt-Hess grade, Fisher CT group) of SAH and vasospasm had only minimal predictive values. The grade at discharge( GOS) was proved to be the best predictor of impairment of cognition and memory function within 1 year after operation. Conclusion : The authors conclude that the diffuse effects of SAH are more important than focal neuropathology in relation to cognitive impairment in this group of patients.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.15-20
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• 2017

Objective : Diagnosing tumor progression and pseudoprogression remains challenging for many clinicians. Accurate recognition of these findings remains paramount given necessity of prompt treatment. However, no consensus has been reached on the optimal technique to discriminate tumor progression. We sought to investigate the role of magnetic resonance perfusion (MRP) to evaluate tumor progression in glioma patients. Methods : An institutional retrospective review of glioma patients undergoing MRP with concurrent clinical follow up visit was performed. MRP was evaluated in its ability to predict tumor progression, defined clinically or radiographically, at concurrent clinical visit and at follow up visit. The data was then analyzed based on glioma grade and subtype. Resusts : A total of 337 scans and associated clinical visits were reviewed from 64 patients. Sensitivity, specificity, positive and negative predictive value were reported for each tumor subtype and grade. The sensitivity and specificity for high-grade glioma were 60.8% and 87.8% respectively, compared to low-grade glioma which were 85.7% and 89.0% respectively. The value of MRP to assess future tumor progression within 90 days was 46.9% (sensitivity) and 85.0% (specificity). Conclusion : Based on our retrospective review, we concluded that adjunct imaging modalities such as MRP are necessary to help diagnose clinical disease progression. However, there is no clear role for stand-alone surveillance MRP imaging in glioma patients especially to predict future tumor progression. It is best used as an adjunctive measure in patients in whom progression is suspected either clinically or radiographically.

• Journal of Korean Neurosurgical Society
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• v.60 no.4
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• pp.465-470
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• 2017

Objective : Magnetic resonance imaging (MRI) grading systems using sagittal images are useful for evaluation of lumbar foraminal stenosis. We evaluated whether such a grading system is useful as a diagnostic tool for surgery. Methods : Between July 2014 and June 2015, 99 consecutive patients underwent unilateral lumbar foraminotomy for lumbar foraminal stenosis. Surgically confirmed foraminal stenosis and the contralateral, asymptomatic neuroforamen were assessed based on a 4-point MRI grading system. Two experienced researchers independently evaluated the MR sagittal images. Interobserver agreement and intraobserver agreement were analyzed using ${\kappa}$ statistics. Results : The mean age of patients (54 women, 45 men) was 62.5 years. A total of 101 levels (202 neuroforamens) were evaluated. MRI grades for operated neuroforamens were as follows : Grade 0 in 0.99%, Grade 1 in 5.28%, Grade 2 in 14.85%, and Grade 3 in 78.88%. Interobserver agreement was moderate for operated neuroforamens (${\kappa}=0.511$) and good for asymptomatic neuroforamens (${\kappa}=0.696$). Intraobserver agreement by reader 1 for operated neuroforamens was good (${\kappa}=0.776$) and that for asymptomatic neuroforamens was very good (${\kappa}=0.831$). In terms of lumbar level, interobserver agreement for L5-S1 (${\kappa}=0.313$, fair) was relatively lower than the other level (${\kappa}=0.804$, very good). Conclusion : MRI grading system for lumbar foraminal stenosis is thought to be useful as a diagnostic tool for surgery in the lumbar spine; however, it is less reliable for symptomatic L5-S1 foraminal stenosis than for other levels. Thus, various clinical factors as well as the MRI grading system are required for surgical decision-making.

• Land and Housing Review
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• v.11 no.4
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• pp.93-98
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• 2020

This study examined the particulate removal performance of three different types of air filters inside a heat exchanger. Of interest was the ability of each filter type in reducing the transmission of outdoor particulate matter of PM10 from entering an apartment while the heat exchanger was in operation. The study tested one commonly used medium filter (E11 grade) and two HEPA filters (H13 grade) of different thicknesses. Two different concentrations of particulate matter were used in the experiment to address different ambient air quality conditions in Korea, 32.75 ㎍/㎥ and 67.26 ㎍/㎥. Study results indicated that under the particulate matter concentration of 32.75 ㎍/㎥, all three filters were capable of removing more than 95% of the fine dust. However at a particulate matter concentration of 67.26 ㎍/㎥, the medium E11 grade filter was only able to remove about 90% of the particulates whereas the HEPA H13 grade filters were able to remove 95% or more of the particulates. The thicker HEPA filter (40T) was also more effective in removing particulates than the thinner HEPA filter (20T) by about 1.6 to 3 percentage points. Based on the findings of this study, it is recommended that HEPA filters of 20T thickness or greater be used during the high air pollution seasons of winter and spring in Korea while medium filters can be used during the other seasons to reduce outdoor air pollution transmission indoors.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.499-506
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• 2022

Objective : We conducted this study with the aim of predicting the biological behavior of meningiomas, and determining the benefits of associating histological subtype and grade with the expression of proliferative markers and tumor suppressor proteins. Methods : The study included 29 patients with primary intracranial and intraspinal meningioma diagnosed in the pathology laboratory of Konya City Hospital between January 2014 and December 2020. Clinicopathological characteristics of the patients including parameters such as age and gender were obtained from the hospital records. Histopathological findings were obtained by re-evaluating the preparations stained with Hematoxylin-Eosin, which were extracted from the archive, and by evaluating new sections obtained from paraffin blocks of patients stained with Ki67, p53, and p57 immunohistochemical stains. Results : A moderate correlation was found between tumor size and Ki67 proliferation index (PI) (p=0.003, r=0.530). There was no significant difference between grade I and grade II tumors in terms of p53 (p=0.184) and p57 (p=0.487) expressions. There were higher levels of Ki67 PI in grade II tumors. The histological subtypes of the tumor had no significant difference with Ki67 PI (p=0.018), p53 (p=0.662), and p57 (p=0.368) expressions. Conclusion : In order to obtain more definitive results, there is a need for studies, which are conducted with a greater number of patients and in multiple centers, and in which a long prospective follow-up is planned. The combination of histological, surgical, and imaging markers could make a more sensitive tool for predicting recurrence, and this could also be tested in future studies.

• Journal of Korean Elementary Science Education
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• v.26 no.1
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• pp.12-23
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• 2007

The purpose of this study was to research the effects of students' evaluation results on teachers' teaching activities. The subjects were 431 elementary school students of 4th, 5th and 6th grade, and 14 teachers of 7 schools located in Seoul, Cheongju, and Daejeon city. The experimental design included pre and post-tests with the control group. Our results found that most of the students had positive thoughts towards science classes. In particular, activities where the teachers provided support in the conduct of experiments and the learning atmosphere generally were evaluated higher than other activities. However, unrestricted experiments were evaluated lower by the students. The feedback from the students' evaluation results of their teachers affected the teachers' teaching activities statistically. The teachers' support during experiments, unrestricted activity during experiments, and evaluation activities were changed positively following the students' feedback. However, the loaming atmosphere and unrestricted activity during experiments were observed to change negatively when the teachers were not given the students' feedback.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.311-317
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• 2007

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.513-521
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• 2010

Most of universities have carried out course evaluation to apply the performance appraisal for professor. But, course evaluation depends on characteristics of each class such as class size, type of lecture, evaluator's grade and so on. As the results, such characteristics of each class lead to serious bias which makes lecturers distrust the course evaluation results. Hence, we propose a equating method for the course evaluation by regression analysis which use stepwise variable selection. And we compare proposed method with the other method by Cho et al. (2009) with respect to efficiencies. Also we give the example to which the method is applied.

• Journal of the Korean Home Economics Association
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• v.34 no.3
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• pp.245-257
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• 1996

The purpose of this study was to investigate the influences of children's perception of maternal acceptance-rejection and self-evaluation on learned helplessness. The Subjects were 371 fifth and sixth grade children. The helplessness scale, PAQ, PARQ were used. The data was analyzed by factor analysis, MANOVA, ANOVA and path analysis which was made through multiple regression analysis. The results were as follows: 1. The children's perceived maternal acceptance was significantly different depending on their parent's education level. In children's perceived parental rejection, there were gender differences. 2. In the children's self-evaluation, there were an interaction effect determined by the child's sex and the mother's education level, and a main effect of mother's education level. 3. Children's learned helplessness was significantly different depending on their mother's education level. 4. Children's perceived maternal acceptance(β=-0.36, p<.01) and rejection (β=0.17, p<.01) had a direct impact on their self-evaluation. Their self-evaluation(β=0.54, p<.01) and perceived maternal rejection(β=0.16, p<.01) had a direct impact on learned helplessness, but perceived maternal acceptance didn't have a direct impact on learned helplessness.