• Education of Primary School Mathematics
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• v.5 no.2
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• pp.121-142
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• 2001

The goal of the National Assessment of Educational Achievement(NAEA) 2001 was to affirm the accountability of school education, to scientifically manage and elevate the quality of education at the national level, and to articulate the final design of the NAEA. It was implemented on June 28th of the year 2001. The assessment frame for NAEA includes the achievement standards, the assessment standards, the instruction for the item development, and the grading policy for mathematics subject. Most of items are multiple-choice types, but the performance-based items should be at least thirty percent of the total items, also 30% in case of mathematics. Approximately 1% of students among entire population of the Grades 6 were randomly selected. Therefore, the finally sampled examines were 8023 at Grade 6. The result of the analysis of the NAEA revealed that Grade 6 students was labelled as ‘average’ level in general (Number and Operation: average, Geometric figures: average, Patterns and Functions: excellent, Measurements: average, Letters and Expressions: average, Probability and Statistics: average). The most characteristic finding was that except for Grade 6(its average is 69.92), most secondary students obtained low test scores and its average of each grade is below 50 out of 100. Especially, the scores on the performance-based items were by and large very low. This finding implies that Korean students are not familiar with the kind of test items which requires expression of ideas and feelings and they are rather familiar with the multiple-choice items. Another interesting finding was that the students in small towns and remote areas showed significantly low scores in all four skills compared with Seoul, metropolitan cities and medium and small cities. This may be attributed from the fact that the remote areas do not have equal learning environment with regard to social and cultural experience, supply of various teaching materials, extracurricular lessons which are directly related to teaching and learning. These findings may be utilized as a reliable resource fur improving curriculum and teaching and learning in Mathematics.

• Journal of the Korean Wood Science and Technology
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• v.37 no.6
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• pp.556-565
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• 2009

Automated visual grading system of lumber needs correct input image. In order to create a correct image of domestic red pine lumber 3.6 m long feeding on a conveyer, part images were captured using area sensor and template matching algorithm was applied to merge part images. Two kinds of template matching algorithms and six kinds of template sizes were adopted in this operation. Feature extracted method appeared to have more excellent image merging performance than fixed template method. Error length was attributed to a decline of similarity related by difference of partial brightness on a part image, specific pattern and template size. The mismatch part was repetitively generated at the long grain. The best size of template for image merging was $100{\times}100$ pixels. In a further study, assignment of exact template size, preprocessing of image merging for reduction of brightness difference will be needed to improve image merging.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.827-836
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• 2021

Objective : Trigeminal neuralgia is one of the most common causes of facial pain. Our aim is to investigate the efficacy and borders of percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia. Methods : Between May 2007 and April 2017, 156 patients with trigeminal neuralgia were treated with radiofrequency thermocoagulation. These 156 patients underwent 209 procedures. In our study, we investigated the early and late results of percutaneous radiofrequency thermocoagulation under guiding fluoroscopic imaging in the treatment of trigeminal neuralgia. Barrow Neurological Institute (BNI) pain scale was used for grading the early results. In addition, Kaplan-Meier survival analysis was used to assess long-term outcomes. Of the 156 patients who underwent radiofrequency thermocoagulation for trigeminal neuralgia, 45 had additional disease. Patients with this condition were evaluated with their comorbidities. Early and late results were compared with those without comorbidity. Results : In 193 of 209 interventions BNI pain scale I to III results were obtained. Out of the 193 successful operation 136 patients (65.07%) were discharged as BNI I, 14 (6.70%) as BNI II, 43 (20.58%) as BNI III. Sixteen patients (7.65%) remained uncontrolled (BNI IV and V). While the treatment results of trigeminal neuralgia patients with comorbidity seem more successful in the early period, this difference was not observed in follow-up examinations. Conclusion : Finally, we concluded that percutaneous radiofrequency thermocoagulation of the Gasserian ganglion is a safe and effective method in the treatment of trigeminal neuralgia. However, over time, the effectiveness of the treatment decreases. Neverthless, the reapprability of this intervention gives it a distinct advantage.

• The Journal of the Korean bone and joint tumor society
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• v.20 no.1
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• pp.7-13
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• 2014

Purpose: As well as patient survival, the restoration of postoperative function such as ambulation is important in limb salvage operations for treatment of malignant bone tumors involving the proximal femur. The authors analyzed clinical outcomes of limb salvage operations using tumor prostheses for metastatic or primary malignant bone tumors in the proximal femur. Materials and Methods: From February 2005 to January 2014, 20 cases (19 patients) with malignant bone tumor involving the proximal femur with pain or complicated pathologic fracture were treated with segmental resection and limb salvage operations with tumor prostheses. Mean age was 63.1 years (range 35-86). Fourteen patients were male and six ones were female. The mean follow-up period was 20 months (1-94 months). There were 15 cases of metastatic bone tumor, 4 cases of osteosarcoma, and 1 case of multiple myeloma. The primary tumors of the metastatic bone tumors included 4 lung cancers, 3 hepatocellular carcinomas, and 3 renal cell carcinomas. Other primary tumors were breast cancer, thyroid cancer, colon cancer, prostate cancer, and malignant spindle cell tumor, each in 1 case. Modular tumor prostheses were used in all cases; (Kotz's$^{(R)}$ Modular Tumor prosthesis (Howmedica, Rutherford, New Jersey) in 3 cases, MUTARS$^{(R)}$ proximal femur system (Implantcast, Munster, Germany) in 17 cases). Perioperative pain was assessed with Visual Analogue Scales (VAS). Postoperative functional outcome was assessed with Musculoskeletal Tumor Society (MSTS) grading system. Results: Out of 20 cases (19 patients), 11 cases (10 patients) survived at the last follow-up. Average postoperative survival of the 9 deceased patients was 10.1 months (1-38 months). VAS score improved from pre-operative average of 8.40 (5-10) to 1.35 (0-3) after operation. Average postoperative MSTS function score was 19.65 (65.50%, 7-28). The associated complications were 2 local recurrences, 3 hematomas, 3 infections, 2 scrotal swellings, and 1 dislocation. There was no case of periprosthetic fracture or loosening. Conclusion: Limb salvage operation with tumor prosthesis is an appropriate treatment for early pain reduction and functional restoration in malignant bone tumors in the proximal femur with pain an/or complicated pathologic fractures.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.2
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• pp.79-86
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• 2011

Purpose: Modular tumor prosthesis is the most popular recontructive modality after resection of malignat tumor in extremity. Complications and survival of tumor prosthesis reconstruction are well-known. however, reports on the long-term outcome of tumor prosthesis in osteosarcoma patientss are scarece. Materials and Methods: In 158 cases as diagnosed as osteosarcoma from feburary 1989 to December 2006 in a single cancer center. We retrospectively reviewd 48 osteosarcoma patients who under went tumor prosthetic reconstruction. Mean follow up preiod was 75.6 months (range; 60 to 179 months). There were 28 males, 20 females and mean age was 22.4 years (range; 11-71). Pathologic subtypes were conventional central osteosarcoma in 46 cases and periosteal in 2 cases. The location of the tumor was proximal tibia (26 cases), distal femor (20 cases), femor diaphysis (1 case), and tibia diaphysis (1 case). In 41 cases built-up-type tumor prosthesis have been used and 7 cases expansion-type tumor prosthesis have been used. We used Musculoskeletal tumor society (MSTS) grading system to asses post operation function, and we analyzed survival rate of patient and tumor prosthesis and complication. Results: The overall survival rate was 77.7% and disease free survival rate was 68.9%. The survival rate of tumor prosthesis was 73%, in last follow up tumor prosthesis has been removed in 12 cases. All of them, 17 complications occurred, which included infection in 16 cases, Periprosthetic Fracture and Loosening of tumor prosthesis in 4 cases, articular instability in 4 cases. MSTS functional score was 74.1% in post operation. Conclusion: In long term follow up result, Primary tumor prosthesis -a reconstruction method after a wide extensional resecion of a bone tumor- can be a effective treatment method in asepect of survival rate, functional assesment and complication.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.6
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• pp.135-154
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• 2020

This paper analyzes the 5,521 samples of the small and medium-sized businesses(SMBs) obtained from the Korea Credit Guarantee Fund. From January 2014 to September 2019, 85% of the SMBs have 5 or fewer full-time employees. The proportion of SMBs is overwhelmed by the elderly men, and most founders are the CEO. Also, about 87% of the workplace types are rented, while 64% of the CEO's residence types are owner-occupation. 47% of the financial grade score is less than 10 points out of 100 and 80% of SMBs have less than 200 million won of the loan guarantee. In particular, the total guarantee loan amount or the days of net guarantee have significantly positive relations with the working period of the CEO in the same industry, the number of employees, the operation period of SMBs, and the corporate business type. In the case of the financial grading score which has the highest weight in overall credit rating gets higher with the higher number of employees, the longer the operation period, and the corporate business type. However, the quantified non-financial grading score has no significant relationship with other explanatory variables, except for the corporate business type. This implies that a non-financial grade score is measured by other determinants that are not observed by the Korea credit guarantee fund. The pure non-financial grade score has positive relations with the working period of the CEO. Overall, this paper would help Korean SMBs upgrade their credit ratings and expand the money supply when there is no standardized credit rating model or no publicly available evaluation criteria for SMBs. We expect this paper provides important insights for further research and policy-makers for SMBs. In particular, to address the financial needs of thin-filers such as SMBs, technology-based financial services (TechFin) would use alternative data to evaluate the financial capabilities of thin-filers and to develop new financial services.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.2
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• pp.126-133
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• 2005

Purpose: to know the treatment result of squamous cell carcinoma in extremity had poor prognosis with risk factor including burn scar and chronic osteomyelitis. Material and Methods: Between Octorber 1993 and September 2002, 20 patients with squamous cell carcinoma in extremity had no distant metastasis was got operation and followed over 36 months. Amputation was done when it was hard to get enough wide margin or neurovascular structure was involved instead of wide excision. Mean age of patients was 57.2 years old and male to female was 16 to 4. TMN staging and histologic grading were performed. Results: There were 6 metastasis (30%) in 20 cases for mean 48.3 months (36-84 months). 3 metastasis to local lymph node and 3 distant metastasis were happened at lung (in 3 cases) and thorasic vertebra (in 1 case). Survival was 18 cases at last look. 5-year survival rate was 50%. 3 local recurrence was developed at average 11 months (4-18 months). Complication was focal skin defect after wide excision and skin graft in 2 cases. The patients by wide excision got average 1.9 time operation and by amputation got average 1.3 time. Conclusion: Squamous cell carcinoma at extremity in Korea had high metastasis rate due to burn scar and chronic osteomyelitis, and it showed equal treatment result which treated by wide excision compared with amputation.

• Journal of Korean Neurosurgical Society
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• v.30 no.1
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• pp.60-65
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• 2001

Objective : The popular grading systems in use, such as Hunt-Hess grade and Fisher scale score, are based primarily on the patient's clinical conditions or computerized tomography score after aneurysmal subarachnoid hemorrhage(SAH). The author investigated whether the need for ventriculoperitoneal(VP) shunt for chronic hydrocephalus and outcome can be predicted by Hunt-Hess grade and Fisher scale. Methods : A series of 146 patients admitted to our hospital from August 1991 to July 1999, who presented with SAH and underwent craniotomy for aneurysm clipping were studied retrospectively. Chronic hydrocephalus was defined as clinically and radiographically demonstrated hydrocephalus that lasted 2 weeks or longer after initial hemorrhage which required shunting. Patients were evaluated based on following factors : Hunt-Hess grade, Fisher scale, age, sex, hypertension, aneurysm location, and intervals from aneurysm rupture to operation. Results : The overall mortality rate of the study group was 8.2%. Hunt-Hess grade(p=0.001) or Fisher scale (p=0.001) at all pretreatment times was significantly correlated with outcome. In addition, there was an increased risk of poor outcome in older age(65<). However, there were statistically no significant relationship between outcome and sex, location of aneurysm, hypertension, and interval from aneurysmal rupture to operation(p>0.05). Of 134 surviving patients, 16 patients(12%) underwent VP shunt placement secondary to chronic hydrocephalus. Hunt-Hess grade(p=0.001) is more predictive of chronic hydrocephalus than Fisher scale(p=0.146). Aneurysm location was significantly correlated with development of chronic hydrocephalus (p<0.05), without significant correlations in sex, age, hypertension. IVH, and ICH. Conclusion : This study suggests that there is a high clinical correlation between outcome and Hunt-Hess grades and Fisher scales on admission, but Hunt-Hess grade is more predictive for chronic hydrocephalus than Fisher scale. In addition, age(<65 yrs) is the significant factor for prediction of outcome. There was a trend of increasing risk for chronic hydrocephalus according to aneurymal location.

• Journal of Chest Surgery
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• v.6 no.1
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• pp.15-22
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• 1973

The definition of cancer, its diagnosis and its prognosis all depend upon description of growth. To the layman a synonym for cancer is a "growth". There are no quantitative terms for the description of growth or growth rate in clinical use. There has been no attempt to assign values that would define "rapidly" or "slowly" growing. Estimates of growth potentiality are implied in the descriptive phrases "poorly differentiated" or "well differentiated", "highly malignant" or "low grade malignancy". and in systems of grading. These qualifying terms represent a personal impression, clinically useful in prognosis, but relative in nature. They do not lend themselves to uniform application or precise measurement for purpose of comparison. Growth is related to size and time. The volume of tumor depends upon the duration of the period of growth and the rate of growth. If the interval and change in volume are known. the average growth rate can be determined. If the growth rate is determined, and assumed to be constant., the duration of a given tumor and the time of inception can be estimated. The commonest concept of the origin of cancer is that as a result of a mutation involving a single cell, succeeding divisions of cells establish a colony with the characteristics recognizable as cancer. If the growth rate of the hypothetical tumor were constant it could be described in terms of "tumor volume doubling time". In the department of thoracic surgery of St. Mary hospital in Catholic Medical College, a clinical evaluation for the growth rate, degree of malignancy, resectability and prognosis was done on a total 24 cases of primary bronchogenic carcinoma which contour was significant on the chest X-ray film as possible estimating the tumor volume doubling time. The following results were obtained: 1. In the cases of 6.0cm or more in diameter of minor size at operation the resectability rate was lower and in the cases of 60 days or more in the tumor or volume doubling time the resectability rate was higher. 2. If differentiation of cancer cells was lower graded in tissue pathology, the tumor volume was shorter and the resectability rate was lower. 3. The tumor volume doubling time of the primary bronchogenic carcinoma occured more over 60 years of age was slightly shorter than under 60 years of age. 4. The tumor size at operation was more important to evaluate the survival time and prognosis than the tumor volume doubling time because the tumor growth was not always constant, we presume.mor volume doubling time because the tumor growth was not always constant, we presume.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.96-106
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• 2004

Purpose: To determine the usefulness of limb salvage operation with recycled autogenous bone graft in musculoskeletal malignant tumors. Materials and Methods: Twenty nine cases, who underwent limb salvage operation with recycled autogenous bone graft for the treatment of musculoskeletal malignant tumor between February 1990 and January 2003, were included. There were 18 males and 11 females and the mean age was 33 years (range, 10 to 65 years). The mean follow-up period was 51.8 months (range, 18 to 117 months). The Enneking stage was IIA in 10 cases and IIB in 19 cases. The recycling method of autogenous bone was deep freezing in 6 cases, autoclaving in 11 cases, pasteurization in 7 cases and the composite of autoclaving and vascularized fibular graft in 5 cases. The union of junctional site was evaluated radiologically and the functional results was analyzed by the grading systems of the International Symposium On Limb Salvages (ISOLS). Results: The mean union time was 7.2 months (range, 3 to 15 months). The union took 5.8 months (range, 4 to 8 months) in deep freezing, 9.7 months (range, 6 to 15 months) in autoclaving, 5.9 months (range, 4 to 8 months) in pasteurization, and 5 months (range, 4 to 8 months) in the composite of autoclaving and vascularized fibular graft. The mean functional evaluation percentage was 76.8% (range, 40 to 90%). It was 65.8% (range, 40 to 85%) in deep freezing, 76.6% (range, 40 to 90%) in autoclaving, 81.6% (range, 70 to 90%) in pasteurization, and 83.4% (range, 75 to 90%) in the composite of autoclaving and vascularized fibular graft. There were 6 cases of complications including 1 case of local recurrence, lung metastasis, infection, fracture, respectively and 2 cases of nonunion. Conclusion: The limb salvage operation with recycled autogenous bone graft is a useful treatment method for the musculoskeletal malignant tumors. Particularly, autoclaving is the most reliable sterilization method. The vascularized fibular graft can compensate decreased osteoinductivity and mechanical strength of recycled bone. So, the composite of autoclaving and vascularized bone graft seems to be a favorable treatment method for high grade malignant musculoskeletal tumors.