Studio Class를 활용한 교육 방법에 대한 사례 연구

김형석,박준석,안달,김선형,Kim Hyeong-Seok,Park Jun-Seok,Ahn Dal,Kim Sun-Hyung 한국공학교육학회 2000 공학교육연구 Vol.3 No.1

In this paper, we are trying to explain an education method using the studio class where a lecturer can teach the theoretical approach for goals of theme, simulation for the theoretical results by using commercial CAD tools, and experiments for the simulation and design results. In order to apply the education skill using studio class to electrical engineering field efficiently, the theoretical approach, simulation procedure, and experiments should be coincided with each other. In this paper, the design procedure of low pass filter for undergraduate and graduate is chosen as an example of studio class In order to show the validity of the proposed education method. By considering the example, the efficiency of the method will be discussed. 본 연구에서는 하나의 주제에 대한 교육 충실도를 높이기 위해 해석적인 수식전개에 바탕을 둔 이론 강의, 상용 소프트웨어를 이용한 수치 시뮬레이션, 그리고 계산 결과를 기초로 얻어진 설계 모델들에 대하여 제작과 실험을 통해 얻어진 결과를 수치계산 결과와 비교 검토의 세가지 접근 방법을 병행할 수 있는 장소를 일컫는 studio class를 활용한 교육방법에 대하여 전자공학교육 분야의 사례연구를 통해 설명하고자 한다. 초고주파 수동소자의 하나인 저역통과여파기에 대해 studio class 개념의 교육과정을 학부생 및 대학원생에게 적용한 결과를 하나의 사례로 들어 국내의 교육환경에 적합한 studio class 교수법에 대한 효과와 학생들의 전문지식 습득에 대한 이해도의 효율성에 대하여 고찰하고자 한다.

HepG2 세포의 산화적 손상에 대한 산삼 추출물의 보호효과 - DNA chip을 이용하여 -

김형석,박희수,권기록,Kim, Hyung-Seok,Park, Hee-Soo,Kwon, Ki-Rok 대한약침학회 2007 Journal of pharmacopuncture Vol.10 No.1

Objectives : This study was carried out to examine protective effect of wild ginseng extract on HepG2 human hepatoma cell line against tert-Butyl hydroperoxide (t-BHP)-induced oxidative damage. Methods : To evaluate protective effect of wild ginseng extract against t-BHP induced cytotoxicity, LDH level and activity of glutathione peroxidase and reductase were measured. Gene expression was also measured using DNA microarray. Results : Wild ginseng extract showed a significant protective effect against t-BHP-induced cytotoxicity in HepG2 cell line. It is not, however, related with the activities of glutathione peroxidase and glutathione reductase. Analysis of gene expression using DNA chip, demonstrated that 28 genes were up-regulated in t-BHP only group. Five genes - selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, serfiredoxin 1 homolog - may be related with the protective effect of wild ginseng extract. Conclusions : Based on the results, a protective effect of wild ginseng extract against t-BHP-induced oxidative damage in HepG2 cell line is not associated with the activities of glutathione peroxidase and glutathione reductase, but with the expression of selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, and serfiredoxin 1 homolog.

슬관절내에 발생한 심부 양성 섬유성 조직구증 - 1례 보고 -

김형석,홍기도,하성식,이영화,이효진,Kim, Hyung-Seok,Hong, Ki-Do,Ha, Sung-Sik,Lee, Young-Hwa,Lee, Hyo-Jin 대한근골격종양학회 1999 대한골관절종양학회지 Vol.5 No.3

Benign fibrous histiocytoma is characteristically composed of fibroblastic and histiocytic cells. Most commonly, this tumor occurs in the dermis and superficial subcutis, but it is uncommon in the knee. We experienced a case of deep benign fibrohistiocytoma in a 38-year-old woman who complained of palpable tender mass on the medial aspect of the right knee. MR imaging findings included a well-delineated oval mass with low signal intensity on T1-weighted and high-signal intensity of T2-weighted images, as well as a marked peripheral contrast enhancement. Histopathologically, the lesion contained a mixture of fibroblastic and histiocytic cells that were often arranged in a cartwheel or storiform pattern and accompanied by varying numbers of inflammatory cells, foam cells, and siderophages. After surgical removal of the lesion, no recurrence was observed.

수퍼 2상 스테인리스강의 열처리 조건변화에 따른 첨가원소 질소의 거동

김형석,전채홍,송권,권숙인 ( Hyung Seok Kim,C . H . Jeon,Gun Song,S . I . Kwun ) 한국열처리공학회 1997 熱處理工學會誌 Vol.10 No.1

After changing the heat treating atmosphere of nitrogen gas, argon gas and vacuum, the nitrogen contents, microstructural changes, hardness and corrosion resistance of 0.25wt.%N alloyed super duplex stainless steel have been investigated in the temperature range from 1050℃ to 1350℃. The nitrogen content showed to be increased up to 0.36wt.% after heat treating the specimen in nitrogen gas at 1200℃, while the decrement of nitrogen content in vacuum atmosphere was shown down to 0.03wt.% at 1350℃. After heat treating in the mixed gas atmosphere of argon and nitrogen at 1250℃, the surface γ phase existed as α+γ phase increased with increasing nitrogen gas content. The γ single phase appeared at the surface above 80%N₂gas, while the surface α single phase was shown below 20%N₂gas. When heat treating the specimen in nitrogen gas at 1050℃, the hardness of austenite phases increased above Hv 40 at the surface layer compared to the hardness of the core parts, while decrement of denitriding effect caused to the hardness nearly unchanged between surface and the core parts after heat treating in vacuum atmosphere. The surface γ single phase specimen showed superior corrosion resistance than the surface α single phase specimen. The surface α phase existed in the α+γ microstructure showed higher corrosion resistance after heat treating in the nitrogen gas atmosphere than the a phase heat treated in the argon gas and vacuum atmosphere.

소아 기능성 변비의 치료에 영향을 미치는 인자

김형석,홍유라,위주희,박재홍,Kim, Hyung-Seok,Hong, You-Rha,We, Ju-Hee,Park, Jae-Hong 대한소아소화기영양학회 2010 Pediatric gastroenterology, hepatology & nutrition Vol.13 No.1

목 적: 소아에서 기능성 변비는 흔히 볼 수 있는 질환이지만 임상적 경과 및 치료 반응에 대한 대단위 연구가 없는 실정이다. 이 질환의 임상적 특징과 치료에 영향을 미치는 인자들을 알아보고자 본 연구를 시행하였다. 방 법: 1998년 1월부터 2007년 12월까지 부산대학교 병원 소아과에서 변비로 치료를 받았던 500명 중 Iowa 기준에 따라 기능성 변비로 1개월 이상 치료를 받고 경과관찰이 가능하였던 240명의 환자를 대상으로 후향적조사를 하였다. 변비의 주 치료제로 락툴로스를 복용한 군(145명)과 PEG (polyethylene glycol)를 복용한 군(95명)으로 나누었다. 환자에 따라 magnesium hydroxide, psyllium, bisacodyl, domperidone, 고장성 인산염 관장액등을 병용하였다. 치료 반응은 약물 투여 후 이틀에 1회 이상 통증이 없이 배변을 하는 시점으로 하였고, 치료 반응이 3개월 이상 유지되면 약물을 감량하였다. 결 과: 1) 남자 142명(59.2%), 여자 98명(40.8%)이었고, 발병 시 연령은 18.7${\pm}$21.5개월, 진단 시 연령은 51.2${\pm}$37.9개월이었다. 발병 시 연령은 1세 이하가 94명(39.2%)으로 가장 많았다. 2) 증상 지속 기간은 32.6${\pm}$33.7개월, 치료 전 배변 빈도는 1회/4.8일이었다. 3) 동반 증상은 유분증 91명(30.4%), 복통 76명(31.6%), 혈변37명(15.4%), 식욕저하 23명(9.6%), 복부팽만 18명(7.5%), 구토 14명(5.8%)이었다. 4) 배변 빈도가 락툴로스 투여군 1회/4.6일로 PEG 투여군 1회/5.2일에 비해 짧았던 것을 제외하고 두 군 간에 차이는 없었다. 5) 치료 반응은 여자에서(p<0.001), 동반증상이 있었을 때(p<0.05), PEG 투여군에서(p=0.001) 의미 있게 빨랐으며, 치료 전 증상 지속 기간이 길수록(p<0.05), 배변 빈도가 적을수록(p<0.05) 늦었다. 6) 총 치료 기간은 성별, 증상 발생 나이, 증상 지속 기간, 배변 빈도, 동반 증상, 유분증 유무, 타병원에서의 치료, 민간 요법 시행, 치료 약물의 종류와 무관하였다. 7) 7명(락툴로스군 6명, PEG군 1명)에서 치료 후 재발이 있었으나, 2명을 제외하고 재치료로 완치되었다. 결 론: 여자, 치료 전 증상 지속 기간 및 배변 빈도가 치료 반응에 중요한 인자였고, PEG가 락툴로스에 비해 치료 반응 시간이 짧았기 때문에 1차 치료 약제로 고려해 볼 수 있겠다. 총 치료 기간에 영향을 미치는 요인은 없었으나, 조기 치료가 치료 반응 및 치료 기간을 단축할 수 있으리라 판단된다. Purpose: The aim of this study was to evaluate the clinical features and factors contributing to treatment outcome for chronic functional constipation in children. Methods: We analyzed the medical records of patients with constipation, who visited the inpatient or outpatient clinic of the Department of Pediatrics of Pusan National University Hospital, between January 1998 and December 2007. The clinical features, outcomes, and factors affecting the treatment response according to the main drug (lactulose vs. PEG 4000) were analyzed retrospectively. Results: Two hundred forty children (142 males and 98 females) were enrolled in this study. The mean age was 51.2${\pm}$37.9 months. The duration of symptoms was 32.6${\pm}$33.7 months. The accompanying symptoms were as follows: encopresis, 91 (30.4%); abdominal pain, 76 (31.6%); and blood-tinged stool, 37 (15.4%). The treatment response was achieved earlier in females (p<0.001), patients with accompanying symptoms (p<0.05), and patients treated with PEG 4000 (p=0.001). The duration of symptoms (p<0.05) and stool frequency before treatment (p<0.05) were related to a delayed treatment response. Relapse occurred in 7 children, all of whom were treated successfully later. Conclusion: Factors contributing to treatment response are female gender, accompanying symptoms, duration of symptoms, and stool frequency before treatment. PEG 4000 is superior to lactulose in response time and taken into consideration as a primary drug for the treatment of functional constipation of children. Early treatment and sufficient treatment time may also be important factors to achieve an early response and prevent relapse.

척수 압박을 동반한 제 3 요추의 골연골종 - 1례 보고 -

김형석,홍기도,하성식,이선우,Kim, Hyung-Seok,Hong, Ki-Do,Ha, Sung-Sik,Lee, Sun-Woo 대한근골격종양학회 1997 대한골관절종양학회지 Vol.3 No.1

본 서울위생병원 정형외과에서는 제 3 요추의 좌측 추궁판과 하 관절 돌기에서 발생하여 척수 압박 증상을 일으킨 골연골종 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. One of the most common benign tumors of bone is the osteochondroma which is a cartilage-capped bony projection on the surface of a bone. It may occur in any bone that has been performed from cartilage, but the most common locations are the long bone at the metaphyseal region of the most active growth cartilage, that is, the lower end of femur, the upper end of the tibia, and the upper end of the humerus. Other bones often involved are the ilium, scapula, fibula, and phalanges of hands and feet. But, the vertebral column is very rare location for osteochondroma. Only one case of osteochondroma involving the lumbar spine has been previously reported in Korea. We report an unusual case of osteochondroma arising from the left lamina and inferior articular process of the 3rd lumbar spine causing spinal cord compression.

동합금의 가공열처리법에 의한 기계적·전기적 성질

김형석,전채홍,송권,권숙인 ( Hyung Seok Kim,C . H . Jeon,Gun Song,S . I . Kwun ) 한국열처리공학회 1997 熱處理工學會誌 Vol.10 No.1

Pure copper is widely used for base material for electrical and electronic parts because of its good electrical conductivity. However, it has such a low strength that various alloying elements are added to copper to increase its strength. Nevertheless, alloying elements which exist as solid solution elements in copper matrix severely reduce the electrical conductivity. The reduction of electrical conductivity can be minimized and the strengthening can be maximized by TMT(Thermo-Mechanical Treatment) in copper alloys. In this research, the effects of TMT on mechanical and electrical properties of Cu-Ni-Al-Si-P, Cu-Ni-Al-Si-P-Zr and Cu-Ni-Si-P-Ti alloys aged at various temperatures were investigated. The Cu alloy with Ti showed the hardness of Hv 225, electrical conductivity of 59.8%IACS, tensile strength of 572MPa and elongation of 6.4%.

국내(國內) 석회석(石灰石)의 품위(品位) 향상(向上) 필요성(必要性)

김형석,Kim, Hyung-Seok 한국자원리싸이클링학회 2011 資源 리싸이클링 Vol.20 No.4

최근까지 국내에서는 노천에 부존된 고품위 석회석이 주로 채광되었기 때문에 고품위 석회석의 매장량은 감소되었다. 현재는 노천에 부존된 고품위 석회석이 고갈되어 석회석의 채굴적이 심부화되고 있다. 그러나 석회석 광체가 심부화될수록 석회석에 함유된 불순물 및 유색광물의 양이 많아져 석회석의 품위가 낮아진다. 따라서 본고에서는 국내 석회석의 광상 특성, 수당현황, 그리고 용도별 규격을 조사하고 국내외 석회석 정제기술의 현황을 분석하여 국내 석회석의 품위를 향상시키는 방안을 모색하였다. Until recently, domestic high grade limestone have mainly mined so high grade limestone deposits have reduced. Because of exhaustion of high grade limestone, mine of limestone have moved from ground to deep position, the grade of limestone become lower because the amount of impurities and colored mineral increased as mining position become deeper. This paper was described about grade improvement of limestone to make a high grade limestone and suitable quality of limestone products by analysis of ore genesis and characteristics, supply and demand situation, use patterns and application standards of domestic lime-stone.

일측성 망막아세포종과 동반된 이소성 정중선 원시신경외배엽종 - 증례보고 -

김형석,조경기,조기홍,윤수한,안영민,안영환,심철,Kim, Hyung Seok,Cho, Kyung Gi,Cho, Ki Hong,Yoon, Soo Han,Ahn, Young Min,Ahn, Young Hwan,Shim, Chul 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.5

Trilateral retinoblastoma is a syndrome involving midline intracranial malignancies in children with the heritable form of retinoblastoma. It is rare and usually lethal in spite of aggressive treatments. We report a case of trilateral retinoblastoma with review of the literature to gain further insight into this uncommon disease.

포수제(捕收劑) 종류(種類)에 따른 공작석(孔雀石)의 부유선별(浮遊選別) 특성(特性)

김형석,김완태,한인규,김상배,Kim, Hyung-Seok,Kim, Wan-Tae,Han, In-Kyu,Kim, Sang-Bae 한국자원리싸이클링학회 2010 資源 리싸이클링 Vol.19 No.4

공작석의 부선에 적합한 포수제를 규명하기 위하여 각종 포수제의 종류에 따른 공작석의 부유선별 특성을 연구하였다. 공작석의 제타전위를 측정한 결과, 공작석의 등전점은 약 pH 8.2로, 등전점 이상의 pH에서는 공작석의 표면이 음(-)으로 하전되고, 등전점 이하에서는 양(+)으로 하전됨을 확인하였다. 공작석은 음이온 포수제인 sodium oleate와 Aeropromoter 845에 의해서 pH 5~11의 범위에서 97%이상 부유되었다. 그러나 alkyl hydroxamate 및 양이온 포수제인 dodecyl trimethyl ammonium chloride와 dodecyl ethyl methyl ammonium chloride에 의해서는 pH 5 이상에서 첨가량에 관계없이 15%미만으로 부유되었다. 공작석을 $(NH_4)_2S$로 황화처리한 후 potassium amyl xanthate로 부선하였을 때, 공작석은 97%이상 부유되었다. 이때 황화처리하지 않았을 때 보다 potassium amyl xanthate의 첨가량이 1/3 정도 적어졌고, 부선시간도 단축되었다. 따라서 공작석의 부선에 적합한 포수제는 potassium amyl xanthate와 음이온 포수제인 sodium oleate 및 Aeropromoter 845이었다. In order to select the proper collector for the flotation of malachite, we had floated malachite by using various collectors. When measuring the zeta potential of malachite, we knew that the point of zero charge of malachite is found at pH 8.2 and malachite particles are negatively charged above this pH value; and positively, below this pH value. The floatability of malachite by the anionic collectors like sodium oleate and Aeropromoter 845, was about 97% in pH 5~11 range, whereas that of malachite by alkyl hydroxamate and the cationic collector like dodecyl trimethyl ammonium chloride and dodecyl ethyl methyl ammonium chloride, was below 15% above pH 5 regardless of dosage increase of collector and flotation time. The malachite sulphidised by $(NH_4)_2S$ was floated above 97% by potassium amyl xanthate. The dosage of potassium amyl xanthate decreased and the flotation period shortened to one third than when it was not sulphidised by $(NH_4)_2S$. Therefore, potassium amyl xanthate and the anionic collectors like sodium oleate and Aeropromoter 845 can be used as the collector of malachite.