중 고등학교 수학교육 개선을 위한 연구

邊龍聖,金東碩,邊東壽,崔雲行,洪慶和,鄭寶鉉 弘益大學校 1991 弘大論叢 Vol.23 No.2

A great many students are working for their mathematics learning in secondary schools and nevertheless its learning effect is rather low. This phenomenon is largely due to a biased social recognition. Furthermore the educational environment including big class size and ability differences enlarge such a difficulty. This study aims at seeking an improving device to enhance learning efficiency under the circumstances. Questionaires about problem finding of teachers educational activity and mathematics teaching were distributed and collected. Data were analyzed to establish a desirable mathematics education and teaching. Devices for individualized instruction and learning tasks and evaluation methods were proposed. This recommendations are supposed to be an improving way for students' mathematics learning. In relation to this result, a further study is strongly required and adminstrative supports by government are badly needed to achieve such a goal.

EGR 쿨러의 전열 특성에 관한 이론 및 수치해석

변민수,서용권,하종률 동아대학교 2001 大學院論文集 Vol.26 No.-

EGR system reduces the NOx as the mixed gas included in the recirculated exhaust gas decreases combustion temperature. The temperature of recirculated exhaust gas is controlled with the EGR cooler in the EGR system. In this study, we studied cooling effect of the EGR cooler with different a cross-section shapes of tubes and the number of tubes. The results show that the cross-section shapes of tubes and the number of tubes slightly influence the temperature drop of the recirculated exhaust gas.

수치모형실험을 통한 콘크리트 구조물의 결함탐지에 관한 연구

김용인,변중무,손권익,서백수 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.B

In this study, First, the results of travel-time inversion (first arrival inversion using the travel-time of the first arrival) were compared with those of full-wave inversion for numerical data. Numerical experiments to find key parameters other than initial velocity model showed that the frequency of source has a great effect on the result of full-wave inversion. Finally, this research presented the corrected full-wave inversion applying the correction term to the final result of full-wave inversion. The corrected full-wave inversion depicted cavities inside concretes even when the inversion started with 20% error in an initial velocity model for cavities. However, full-wave inversion did not reveal cavities.

睡液中 Testosterone의 含量과 血淸中 High Density Lipoprotein Cholesterol의 消長이 座瘡發生에 미치는 效果

李容五,卞種秀 慶北大學校 齒科大學 1985 慶北齒大論文集 Vol.2 No.1

Sex hormone levels are possibly related to risk of heart disease through lipoprotein levels, specifically high density lipoprotein (HDL) cholesterol. HDL cholesterol is a powerful protective factor. Women have higher HDL cholesterol levels than men. Female sex hormones appear to be strongly related to HDL cholesterol; estrogen increases and progesterone decrease HDL cholesterol levels. There is some suggestion that pharmaceutical doses of testosterone will lower HDL cholesterol levels. Little is known about the relation between endogenous testosterone and HDL cholesterol levels. Acne is considered to be an androgen dependent condition and free testosterone in saliva is a useful marker of androgenicity in acne. Hence concentrations of salivary and serum testosterone, serum HDL cholesterol, total cholesterol, triglycerides and phospholipids were determined in male and female patients with varying grades of acne. Levels of salivary testosterone in male patients with acne cystica were slightly higher than those of men without acne, while men and women with acne vulgaris and women with acne cystica had normal salivary testosterone values. Levels of serum testosterone in male and female patients with acne (vulgaris or cystica) were not significantly different from those of controls. Levels of HDL cholesterol in male and female patients with acne cystica were significantly reduced as compared with levels in sex-matched controls and patients with acne vulgaris, while levels of total cholesterol, triglycerides and phospholipids in male and femal patients with acne (vulgaris or cystica) were not significnat. Salivary testosterone levels were negatively correlated with HDL cholesterol in male patients with acne, while salivary testosterone levels were positively correlated with HDL cholesterol in femal patients with acne.

위장관 출혈을 일으킨 공장의 형활근종 1예

김병수,장성종,부귀범,조운택,박찬국,김만우,변주남,김정용,전호종 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.1

Small bowel leiomyoma is a rare tumor which may occur wherever smooth muscle is present. The small bowel is the most common site and it makes up 20~30% of all benign small intestinal neoplasms. A spectrum of symptoms are common ranging from nausea, vomiting, abdominal pain, to massive intestinal bleeding. Bleeding is the most common symptom and is usually gross and recurrent. Occasionally it may be life threatening. But, the most serious problem is both the absence of specific clinical symptoms, and the difficulties shown in radiological diagnostics of the small bowel. If conventional diagnostic methods fail to reveal any positive findings for gastrointestinal bleeding, the diagnosis of intestinal leiomyoma should be suspected and an SMA angiography shoud be performed. The angiographic criteria of small bowel leiomyoma is very characteristic. We present a case of leiomyoma with considerable and prolonged gastrointestinal bleeding, which was diagnosed by angiography. A 61-year old woman was admitted with a history of melena over the last 10 days. An SMA angiography showed a hypervascular mass with a diameter of 3×3cm. A segmental resection was performed under the impression of the gastrointestinal bleeding due to leiomyoma of the small bowel. Microscopic examination of the lesion shows interlacing or whorl bundles of spindle shaped ces and no mitosis.

흡연에 의한 레진의 색상변화에 관한 실험적 연구

이용근,장광수,변호영 원광대학교 생체재료·매식연구소 1995 원광생체재료·매식 Vol.4 No.2

Extrinsic dental stain may cause considerable cosmetic problems. Cigarette smoking can stain intraoral restorations, and the extent of stain accumulation will very depending. on the chemical properties of materials, surface roughness and surface treatment. This laboratory investigation was designed to simulate clinical stain accumulation from smoking using a smoking chamber. The purpose of this study was to determine and compare the extent of stain on some dental resins caused by cigarette smoking using a color difference meter(CIELAB color scale). Four kinds of light cured composite resins. (ALF, EST, TPH, Z10), three kinds of acrylic denture base resins(VRS, VSC, PS2), enamel, and dentin were investigated. Resin specimens of 3 mm thickness were made according to the manufacturer's instructions and were finally polished with Microcloth(Buehler). Half of the specimens were thermocycled between 5-55 ℃ for 1,000 cycles. Enamel and dentin specimens were made by ground and polished until flat and polished. L, a and b value of specimens were measured using a Colorimeter (Model TC-6FX, Tokyo Denshoku Co.) All the specimens were initially exposed to the smoking chamber for 4 hours and then exposed an additional 4 hours. Conditions in the smoking chamber were 37℃ and 100% relative humidity. It was filled with cigarette smoke. After removal from the smoking chamber, the surface of each specimen was wiped with tissue paper and then L, a and b value of specimens were measured. After 4 hours of exposure, the discoloration of dentin and enamel was most prominent(p<0.05), and the color change of heat cured acrylic resin was the least followed by light cured composite resin. Thermocycling did not affect the amount of discoloration. The discoloration after 8 hours of exposure was significantly(p<0.05) greater than that after 4 hours, and the amount of discoloration was more than five times greater. In conclusion, 8 hours storage in a smoking chamber caused significant color change(ΔΕ). The stains were smallest on heat cured acrylic resin and light cured composite resin.

뇌손상 후 운동신경기능 회복 기전 : 기능적 뇌 자기공명영상의 유용성 The Usefulness of fMRI Study

장성호,한봉수,장용민,변우목,김성호,조윤우 한국뇌학회 2001 한국뇌학회지 Vol.1 No.1

목적: 본 연구는 뇌손상환자에서 기능적 뇌 자기공명영상(functional magnetic resonance imaging, fMRI)을 이용한 대뇌운동피질 뇌지도화를 시행하여, 운동신경기능 회복 기전에 대한 기능적 뇌 자기공명영상의 유용성에 대하여 연구하였다. 방법: 신경학적 증상과 병력이 없는 성인 8명과 뇌손상환자 5인을 대상으로 하였다. 뇌손상환자 중 2명은 뇌종양환자이었으며 1명은 뇌출혈, 1명은 뇌경색, 1명은 뇌낭미충증환자이었다. 기능적 자기공명영상은 1.5T MR scanner로 Blood Oxygen Level-Dependent(BOLD) 기법을 적용하였다. 운동과제는 손가락을 1-2Hz의 주기로 쥐었다 펴기를 반복하도록 하였다. 결과: fMRI를 촬영한 결과 정상인 8인, 즉 총 16개의 손중 15개의 손과 환자 5인의 이환되지 않은 손운동시 반대측 일차 운동피질 꼭지(knob)를 중심으로 일차 감각운동피질(SM1)이 활성화되었다. 정상인 중 1인의 한 손에서 반대측 SM1과 동측 일차 운동피질(primary motor cortex, M1) 및 보조운동영역이 동시에 활성화되었다. 뇌손상환자의 이환측 손운동시 환자 1에서는 일차감각피질(primary sensory cortex, S1), 환자 2와 환자 3에서는 양측 SM1, 환자 4와 환자 5에서는 반대측 SM1이 활성화되었다. 환자 1에서는 손상된 M1의 운동신경기능이 S1으로 이전된 것으로 추정되며, 환자 4와 5에서는 손의 운동신경기능이 피질척수로에 의하여 유지되고 있는 것으로 추정되었다. 그러나 환자 2와 환자 3에서 발견된 동측 운동피질 활성화는 본래 정상적으로 존재하던 운동신경 경로인지 뇌손상 후에 발생한 운동신경기능 회복 경로인지 구분할 수는 없었다. 결론: fMRI을 통한 대뇌 운동피질 지도화는 뇌손상 후 병변 주위로의 재조직되는 회복 기전과 피질척수로에 의해 운동신경기능이 유지되고 있음을 입증하는데에 유용할 것으로 생각된다. Objective: This study investigated the usefulness of functional magnetic resonance imaging (fMRI) in the research of motor recovery mechanisms in brain injured patients. Method: Eight control subjects and five brain injured patients were investigated. Out of five patients, two were with brain tumor, one cerebral hemorrhage, one cerebral infarction, and one neurocysticercosis. fMRI was performed using the blood oxygen level-dependent (BOLD) technique at 1.5 TMR scanner with a standard head coil. The motor activation task consisted of finger flexion-extension exercises in 1-2 Hz cycles. Results: fMRI showed activation of the contralateral primary sensori-motor cortex(SM1) by the hand movements of all control subjects and by the unaffected hand movements of all brain-injured patients. Activation of the supplementary motor area(SMA) by one hand movement was also seen in one control subject. Hand movements of the affected hand of the brain injured patients resulted in activation of the contralateral primary sensory cortex(S1) in patient 1, both SM1 in patients 2 and 3, and the contralateral SM1 in patients 4 and 5. Conclusions: It is concluded that fMRI is useful for the research of perilesional reorganization and sparing of the corticospinal tract during the motor recovery mechanisms after brain injury.

Cyclosporine 0.05% Ophthalmic Emulsion for Dry Eye in Korea: A Prospective, Multicenter, Open-Label, Surveillance Study

Byun, Yong-Soo,Rho, Chang Rae,Cho, Kyungjin,Choi, Jin A,Na, Kyung Sun,Joo, Choun-Ki The Korean Ophthalmological Society 2011 Korean Journal of Ophthalmology Vol.25 No.6

<P><B>Purpose</B></P><P>To assess the effectiveness and tolerability of cyclosporine ophthalmic emulsion (CsA) 0.05% in patients with moderate to severe dry eye disease in Korea.</P><P><B>Methods</B></P><P>This was a prospective, multicenter, open-label, surveillance study of 392 Korean patients with moderate to severe dry eye disease who were treated with CsA 0.05% for three months. An assessment of effectiveness was performed at baseline, and after 1, 2, and 3 months. The primary effectiveness outcomes were changes in ocular symptoms and Schirmer score. The secondary effectiveness outcomes were a change in conjunctival staining, use of artificial tears, global evaluation of treatment, and patient satisfaction. The primary safety outcome was the incidence and nature of adverse events.</P><P><B>Results</B></P><P>A total of 362 patients completed the study. After three months, all ocular symptom scores were significantly reduced compared to the baseline values, while the Schirmer scores were significantly increased relative to baseline (<I>p</I> < 0.0001). After three months, there were significant reductions from baseline in conjunctival staining (<I>p</I> < 0.01) and use of artificial tears (<I>p</I> < 0.0001). According to clinicians' global evaluations, most patients (>50%) experienced at least a 25% to 50% improvement in symptoms from baseline at each follow-up visit. The majority of patients (72.0%) were satisfied with the treatment results, and 57.2% reported having no or mild symptoms after treatment. The most common adverse events were ocular pain (11.0%).</P><P><B>Conclusions</B></P><P>Our findings indicate that CsA 0.05% is an effective and tolerable treatment for dry eye disease in Korean clinical practice.</P>

The Roles of Social Capital and Parental Financial Preparation in College Completion in the United States

Soo-yong Byun,Doo Hwan Kim 한국사회학회 2014 韓國社會學 Vol.48 No.6

Using data from the National Education Longitudinal Study of 1988-2000, this study examines how social capital shapes parental financial preparation for children’s college education and how social capital and parental financial preparation in turn affect children’s four-year college completion in the United States. Results show that social capital is significantly related to parental financial preparation for their teenagers’ college education, even after controlling for other variables. Results also show that while both social capital and parental financial preparation increase the odds of children completing college, parental financial preparation has a greater impact for children from low-income families than for children from high-income families. Together, the findings suggest that social capital matters to four-year college completion of adolescents either directly or indirectly through its influence on parental financial preparation.

Original Articles : Cyclosporine 0.05% Ophthalmic Emulsion for Dry Eye in Korea: A Prospective, Multicenter, Open-Label, Surveillance Study

( Yong Soo Byun ),( Chang Rae Rho ),( Kyung Jin Cho ),( Jin A Choi ),( Kyung Sun Na ),( Choun Ki Joo ) 대한안과학회 2011 Korean Journal of Ophthalmology Vol.25 No.6

Purpose: To assess the effectiveness and tolerability of cyclosporine ophthalmic emulsion (CsA) 0.05% in patients with moderate to severe dry eye disease in Korea. Methods: This was a prospective, multicenter, open-label, surveillance study of 392 Korean patients with moderate to severe dry eye disease who were treated with CsA 0.05% for three months. An assessment of effectiveness was performed at baseline, and after 1, 2, and 3 months. The primary effectiveness outcomes were changes in ocular symptoms and Schirmer score. The secondary effectiveness outcomes were a change in conjunctival staining, use of artificial tears, global evaluation of treatment, and patient satisfaction. The primary safety outcome was the incidence and nature of adverse events. Results: A total of 362 patients completed the study. After three months, all ocular symptom scores were significantly reduced compared to the baseline values, while the Schirmer scores were significantly increased relative to baseline (p < 0.0001). After three months, there were significant reductions from baseline in conjunctival staining (p < 0.01) and use of artificial tears (p < 0.0001). According to clinicians` global evaluations, most patients (>50%) experienced at least a 25% to 50% improvement in symptoms from baseline at each follow-up visit. The majority of patients (72.0%) were satisfied with the treatment results, and 57.2% reported having no or mild symptoms after treatment. The most common adverse events were ocular pain (11.0%). Conclusions: Our findings indicate that CsA 0.05% is an effective and tolerable treatment for dry eye disease in Korean clinical practice.