초등학교 과학 수업에서 개념도 활용의 효과

강석진,이유영,고한중,전경문,노태희 한국초등과학교육학회 2004 초등과학교육 Vol.23 No.1

In this study, we investigated the effects of using concept mapping as an instructional tool on 4th graders' achievement, science learning motivation, and attitude toward science classes. T재 classes (38 students) from an elementary school were respectively assigned to a control group and a treatment group. Students were taught about "expansion of matter by heat" and "heat transfer". These topics were chosen because they require students to understand more concepts as well as relationships among them. A science learning motivation test and an attitude toward science classes test were administered as pretests. A researcher-made achievement test, the science learning motivation test, and the attitude toward science classes test were administered as posttests. The results indicated that using concept mapping in 4th-grade science classes was not significantly effective in improving students' achievement though a statistically significant positive effect was found in the subcategory of knowledge. No statistically significant effect of using concept mapping was found in the scores of the science learning motivation test and the attitude toward science classes test. Educational implications are discussed.

A Pulsed Dynamic Load Modulation Technique for High-Efficiency Linear Transmitters

Moon-Suk Jeon,Jung-Lin Woo,Sunghwan Park,Youngwoo Kwon IEEE 2015 IEEE transactions on microwave theory and techniqu Vol.63 No.9

<P>A pulsed dynamic load modulation (PDLM) technique is introduced for a high-efficiency linear transmitter for wideband modulation signals with a large peak-to-average power ratio. By combining the dynamic load modulation technique with the class-S amplifier concept, the pulse-width-modulated envelope signal is applied to the switchable-load matching circuit so that the power amplifier (PA) can operate near optimum efficiencies in the backed-off power region. A comprehensive analysis is presented to prove the circuit concept using the simplified theory, followed by the full circuit simulations using harmonic-balance analysis. The effect of nonideal terminations at the intrinsic device plane is also analyzed to understand the potential issues in the practical implementation. The proof-of-concept circuits are designed and fabricated using a silicon-on-insulator CMOS process, where a two-stage PA, a load switch, a pulse-width modulation circuit, and a switch driver are implemented in two separate chips. The fabricated PDLM PA operating at 837 MHz shows continuous-wave efficiencies in excess of 44% across the 6-dB power back-off region from the saturated output power. A power-added efficiency as high as 43.4% is achieved at the output power of 24.8 dBm using 10-MHz-bandwidth 16 quadrature amplitude modulation long-term evolution (LTE) signals. Unlike the case of the envelope-tracking techniques, the PDLM PA of this work maintains the overall efficiencies as the LTE signal bandwidth increases. The PDLM PA of this work can provide a potential solution for high-efficiency PAs for future mobile terminals using wideband modulation signals.</P>

DMBA 유도 햄스터 협낭암 발생과정에서 방사선 조사가 증식세포핵항원(PCNA)의 발현과 apoptosis 유발에 미치는 영향

전인성,허민석,최항문,이삼선,최순철 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.3

Purpose : This study was carried out to investigate the effect of irradiation on the expression of proliferating cell nuclear antigen (PCNA) and apoptosis induction during the carcinogenesis in hamster buccal pouch. Materials and methods : Three months old Syrian golden hamsters were divided into control and 2 experimental groups, Hamsters in control group were left untreated on buccal pouchs. Twenty four hamsters were treated with 0.5% DMBA tri-weekly on the right buccal pouch. Forty eight hamsters were treated with 0.5% DMBA tri-weekly and irradiated with the dose of 5 Gy and 10 Gy at 6,9, 12, 15 weeks after DMBA application. Resected buccal pouches were sectioned and examined for potential expression pattern of PCNA and apoptosis. Results : The PCNA index was increased with the stages of buccal pouch epithelium carcinogenesis except the hyperplasia stage in control group (p< 0.05). The irradiation did not effect on the PCNA index in the dysplasia and the carcinoma in situ stage, but in the hyperplasia stage, the PCNA index was increased with 10 Gy radiation and decreased in the carcinoma stage (p< 0.05). The apoptotic index was significantly decreased from the carcinoma in situ stage and the lowest in the carcinoma stage, The apoptotic index was significantly decreased in the hyperplasia and dysplasia stage with the 5 Gy irradiation and significantly increased only in the carcinoma stage with the 10 Gy irradiation (p< 0.05). Conclusion : The PCNA and apoptotic index were varied according to the irradiation period and dosage in each carcinogenesis stage. (Korean J Oral Maxillofac Radiol 2000; 30: 207-216)

Enhanced Sintering Behavior and Electrical Properties of Single Phase BiFeO₃ Prepared by Attrition Milling and Conventional Sintering

Jeon, Nari,Moon, Kyoung-Seok,Rout, Dibyranjan,Kang, Suk-Joong L. The Korean Ceramic Society 2012 한국세라믹학회지 Vol.49 No.6

Dense and single phase $BiFeO_3$ (BFO) ceramics were prepared using attrition milled calcined (coarse) powders of an average particle size of ${\approx}3{\mu}m$ by conventional sintering process. A relative density of ${\approx}96%$ with average grain size $7.3{\mu}m$ was obtained when the powder compacts were sintered at $850^{\circ}C$ even for a shorter duration of 10 min. In contrast, densification barely occurred at $800^{\circ}C$ for up to 12 h rather the microstruce showed the growth of abnormal grains. The grain growth behavior at different temperatures is discussed in terms of nonlinear growth rates with respect to the driving force. The sample sintered at $850^{\circ}C$ for 12 h showed enhanced electrical properties with leakage current density of $4{\times}10^{-7}A/cm^2$ at 1 kV/cm, remnant polarization $2P_r$ of $8{\mu}C/cm^2$ at 20 kV/cm, and minimal dissipation factor (tan ${\delta}$) of ~0.025 at $10^6$ Hz. These values are comparable to the previously reported values obtained using unconventional sintering techniques such as spark plasma sintering and rapid liquid phase sintering.

Paenibacillus sacheonensis sp. nov., a xylanolytic and cellulolytic bacterium isolated from tidal flat sediment.

Moon, Jeong Chan,Jung, Young Jun,Jung, Ji Hyun,Jung, Hyun Suk,Cheong, Young Ryun,Jeon, Che Ok,Lee, Kyun Oh,Lee, Sang Yeol Society for General Microbiology 2011 International journal of systematic and evolutiona Vol.61 No.11

<P>A Gram-negative-staining, rod-shaped bacterium, designated strain SY01(T), was isolated from tidal flat sediment from Sacheon Bay, South Korea. Strain SY01(T) was characterized with respect to its phenotypic and phylogenetic characteristics. The novel strain was spore-forming, motile, catalase-negative and oxidase-positive. Optimal growth of the strain occurred at 30 C and pH 7.0. The DNA G+C content was 56.1 mol%. The predominant menaquinone was MK-7. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and several unknown lipids were detected in the polar lipid profile. Anteiso-C(15 : 0) (47.2 %), iso-C(15 : 0) (18.9 %) and iso-C(16 : 0) (10.5 %) were the major cellular fatty acids of strain SY01(T). The highest 16S rRNA gene sequence similarities were found with Paenibacillus phyllosphaerae PALXIL04(T) (95.9 %), Paenibacillus tarimensis SA-7-6(T) (94.6 %) and Paenibacillus mendelii C/2(T) (94.4 %). Based on the phylogenetic, chemotaxonomic and physiological characteristics presented in this study, strain SY01(T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillus sacheonensis sp. nov. is proposed. The type strain is SY01(T) ( = DSM 23054(T) = KACC 14895(T)).</P>

객체지향 기법에 의한 공정 제어 및 감시 시스템의 모델링에 관한 연구

전중남,김석일,문병곤 충북대학교컴퓨터과학연구소 1996 컴퓨터과학연구 Vol.4 No.1

공장 자동화를 위한 소프트웨어의 설계는 매우 복잡하고 많은 비용과 시간을 필요로 한다. 대부분의 공정 감시 및 제어 시스템은 작업 현장 마다 공정의 구성이 다르기 때문에 해당 공정에 맞는 소프트웨어를 독립적으로 설계되어 왔다. 또한 같은 공정이라 할지라도 생산 설비와 제품의 사양이 변경되면, 많은 양의 소프트웨어를 다시 설계하는 불편을 감수하였다. 본 연구에서는 작업 현장에서 간단한 파라미터들을 수정함으로써 공정의 변경에 대응할 수 있도록 유연성 있는 공정 감시 및 제어 프로그램의 개발을 위한 요구사항을 OMT (Object Modeling Technique)에 의하여 분석하였다. 객체 모델에 의하여 생산 라인의 하드웨어적인 연결관계 및 제어 및 감시에 필요한 정적 요소들을 표현하였다. 동적 모델에 의하여 공정의 감시 및 제어는 유한 상태 기계로 표현될 수 있음을 예를 들어 설명하였으며, 기능 모델에 의하여 데이타의 흐름을 표현하였다. 이러한 모델링 과정을 거쳐 실제로 공정 제어 및 관리 시스템을 구현하기 위하여 제어, 데이타 베이스 관리, 그래픽 에디터, 그리고 보고서 양식 편집기 등이 어떠한 요구사항을 필요로 하는 지를 분석하였다.

Free Paper Session : LC & Liver Fibrosis ; Hepatic vein arrival time using a microbubble contrast enhanced ultrasonography in non-invasive assessment of the severity of portal hypertension in cirrhotic patients (초)

( Moon Young Kim ),( Ki Tae Suk ),( Soon Koo Baik ),( Hyoun A Kim ),( Hong Jun Park ),( Hyo Keun Jeon ),( So Yeon Park ),( Bo Ra Kim ),( Jin Heon Hong ),( Ki Won Jo ),( Sang Ok Kwon ) 대한간학회 2011 Clinical and Molecular Hepatology(대한간학회지) Vol.17 No.3(S)

대정맥-심방 우회술로 치료한 기질화된 혈전에 의한 하대정맥 폐쇄 : 증례 보고

문철,임훈,전훈배,염욱,윤익진,이석열,정윤섭 대한혈관외과학회 1999 Vascular Specialist International Vol.15 No.1

Suprarenal IVC obstruction occurs rarely but has various causes. Because this obstruction proceed chronically and usually has collateral circulation, if there is no IVC or hepatic vein obstruction symptom such as Budd-Chiari syndrome, operation is usually needless. However, although symptom is not combined, if malignancy can not be ruled out and there is no proper and radiologically visible collateral, mass resection with IVC wall and bypass graft should be done. 58 year-old female patient visit the hospital for IVC mass that is occasionally discovered by routine abdominal ultrasonography examination. After abdominal CT scanning and IVC venography, IVC obstructive mass between renal vein and hepatic vein was found. Patient didn't show any abnormality in hematological examination such as coagulation and platelet counts. There was no IVC obstruction symptom such as lower limb swelling. Inferior hepatic vein was abnormally dilated and this was regarded as collateral vessel for IVC obstruction. Radiologically, primary leiomyosarcoma was not ruled out and so operation was decided. Suprarenal IVC was dissected and mass was exposed. And with the use of femoral vein and right atrium, temporally veno-veno bypass was performed. Mass including IVC wall was excised and upper end of divided IVC was sutured. Lower end of divided IVC was anastomosed with 16 mm Dacron graft and graft was anastomosed with right atrium by end-to-end methods (Cavoatrial shunt). Postoperative pathologic examination revealed the mass to be organized thrombi. After 2 weeks later, follow-up IVC venography was performed and good patency was found from IVC to right atrium through artificial bypass graft and patient was discharged without complications.

콩의 종류와 가공 조건에 따른 isoflavone 의 함량 변화

전기숙,황인경,문보경 한국조리과학회 1996 한국식품조리과학회지 Vol.12 No.4

본 연구에서는 우리나라에서 재배되고 있는 14종의 콩을 수집하여 콩전체와 각 부위의 isoflavone 중 genistein과 daidzein의 함량을 분석하고 시판 콩 가공식품과 실험실에서 가공 조건을 달리하여 제조한 콩식품의 isoflavone을 genistein과 daidzein 함량의 합으로 계산하였다. 콩 품종에 따른 isoflavone 함량의 차이는 매우 커서 그 농도 범위가 308.2-1,134.2 ㎍/g으로 다양했으며 isoflavone을 가장 많이 함유한 품종은 단엽콩이었다. 콩을 각각 배아,배유,종피로 부위를 나누어 isoflavone 함량을 분석한 결과는 배아에 가장 높은 농도의 isoflavone이 함유되어 있는 것으로 나타났으며 종피에서 가장 낮은 농도를 보였다. 콩 전체로 볼때 daidzein과 genistein의 함량 비율(D/G)은 1-2정도 이었으나 배아, 배유, 종피에서는 특징적으로 다르게 나타나 배아에서의 D/G는 4-12로 상당히 높았으며, 배유와 종피에는 D/G의 비율이 0.1-4로 약간 높거나 오히려 genistein이 더 많이 함유된 품종도 있었다. 수침시간을 달리하여 제조한 두유의 isoflavone 함량은 수침시간이 8시간에서 16시간으로 길어짐에 따 라 1.1-1.2배 정도 감소하였으나 시판 두유보다 약 7배 정도 높았다. MgCl₂응고제를 사용하여 제조한 두부의 isoflavone 함량은 CaSO₄응고제를 사용한 두부보다 더 높았으나, 시판 두부와 큰 차이를 보이지는 않았다. 시판 콩나물의 부위별 isoflavone 함량은 뿌리에 55.8-142.8 ㎍/g, 머리에 149.8-189.3 ㎍/g, 줄기에 3.4-8.8 ㎍/g 정도 존재하는 것으로 나타나서 머리나 뿌리에 많은 양의 isoflavone이 함유되어 있었다. 시판 고추장은 2.8-3.0 ㎍/g 정도의 낮은 isoflavone함량을 나타내었으며 시판 된장의 경우는 49.1-63.6 ㎍/g 정도의 isoflavone을 함유하고 있는 것으로 나타나서 제조 업체간에 많은 차이를 보였다. Genistein (G), and daidzein (D), the major isoflavones, were analyzed in 14 varieties of Korean soybean and various processed soybean products by using high performance liquid chromatography. Isoflavone contents (G+D) were greatly variable among varieties ranged from 308.2 ㎍/g to 1,134.2 ㎍/g and highest in Danyopkong and Jinpumkong. Among hypocotyl, cotyledon and hull of soybean the concentration of the isoflavone (G+D) in the hypocotyl was highest ranged from 2,971.7 ㎍/g to 5,704.9 ㎍/g. The distributions of genistein and daidzein were also different in hypocotyl, cotyledon and hull. Higher ratio of daidzein to genistein (D/G) was found in the hypocotyl (4-12) compared to cotyledon and hull (0.1-4). Isoflavone (G+D) contents of soymilks (Sinpaldal#2, Eunhakong) prepared at 16 hour hydration were decreased to 1.1-1.2 times compared with that at 8 hour hydration. Commercial soymilks contained much lower isoflavone (G+D) than laboratory soymilks. Soybean curd (Eunhakong) prepared with MgCl₂showed higher isoflavone (G+D) contents than that with CaSO₄. But these values of two different soybean curds made at laboratory were similar to those of 3 commercial curds. The concentration of the isoflavones in soybean sprout separated with 3 parts revealed highest in the head and lowest in the stem. Compared with non-fermented soybean foods the fermented soybean products, Kochujang and soybean paste, Duen Jang, showed very low contents of isoflavone (G+D), 2.8-3.0 ㎍/g, 35.9-63.6 ㎍/g respectively.

공황장애 및 주정의존 환자들의 혈장 Serotonin과 5-HIAA 농도에 대한 연구

문석환,송동근,유태혁,박상욱,김영희,최인근,정전섭 大韓神經精神醫學會 1995 신경정신의학 Vol.34 No.1

To investigate the serotonergic function of alcohol dependence patients with that of panic disorder patients, the plasma serotonin and 5-HIAA were measured by HPLC method. The subjects were panic disorder patients (N-8), alcohol dependence patients (N=10) and normal controls(N=10). The results were as follow : 1) Alcohol dependence patients showed lower plasma serotonin concentrations than the other two groups. 2) Alcohol dependence patients had the highest plasma 5-HIAA concentrations among the three groups. and panic disorder patients had higher plasma 5-HAA concentrations than controls. 3) The ratio of serotonin/5-HIAA in the plasma were lowest in alcohol dependence patients among the three groups, and were lower in panic disorder patients than in normal controls. 4) The total amounts of plasma serotonin and 5-HIAA showed no differences among the three group. From the results, there were significant differences among alcohol dependence patients, panic disorder patients and normal controls in the ratios of serotonin/5HIAA in the plasma. Alcohol dependence patients had higher rate of serotonin metabolism than the normal controls and alcohol dependence and panic disorder patients had biological similarity in serotonin metabolism suggesting abnormal serotonergic system, different from that of normal controls.