• 정보교육학회논문지
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• 제9권4호
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• pp.649-659
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• 2005

공간적 표현에 대한 지식은 공간적 배열의 특징과 그 특징들 사이의 관계를 그들의 기능을 고려하여 인지하는 방식과 연관이 있는 바, 본 연구에서는 웹기반 교육에 있어서 두 가지의 정보제공 창의 형태(타일창, 단일창)를 학습자의 공간지각력과 연관지어서 비교, 분석하였다. 본 연구는 공간지각력과 정보제공 창의 형태에 대한 상호작용을 학생들의 인지적 지식의 습득도를 통해 조사, 연구하기 위해 미국 펜실베니아 주의 Falk School에 재학 중인 71명의 초등학생을 대상으로 공간지각력에 대한 사전검사를 실시하고 두 실험 집단으로 나누어 과학내용에 관한 웹기반 수업을 실시하였다. 사후검사를 통해 학생들의 인지적 지식의 습득도가 측정되었고 이는 다변량 선형 회귀분석을 실시한 바에 의하면, 공간 지각력은 사후 검사 점수에 명백하게 통계적으로 유의한 주효과를 보였다. 이 같은 결과는 전체표본과 부표본에서 모두 나타났다. 웹 기반 학습에서의 아동들의 인지적 지식의 습득도는 그들의 공간지각력과 정(+)의 관계가 있으며, 공간지각력과 정보 제공 창의 형태 사이에 상호 작용의 패턴이 있음을 알 수 있는데, 이는 웹 기반 학습에 있어서 공간지각력이 낮은 학생들은 타일창에서 인지적 지식의 습득도가 더 높게 나타났고 공간지각력이 높은 학생들은 단일창에서 인지적 지식의 습득도가 더 높게 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.441-441
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• 2009

Dye-sensitized solar cells (DSSCs) have been widely investigated as a next-generation solar cell because of their simple fabrication process and low coats. The cells use a porous nanocrystalline TiO2 matrix coated with a sensitizer dye that acts as the light-harvesting element. The photo-exited dye injects electrons into the $TiO_2$ particles, and the oxide dye reacts with I- in the electrolyte in regenerative cycle that is completed by the reduction of $I_3^-$ at a platinum-coated counter electrode. Since $TiO_2$ porous film plays a key role in the enhancement of photoelectric conversion efficiency of DSSC, many scientists focus their researches on it. Especially, a high light-to-electricity conversion efficiency results from particle size and crystallographic phase, film porosity, surface structure, charge and surface area to volume ratio of porous $TiO_2$ electrodes, on which the dye can be sufficiently adsorbed. Effective treatment of the photoanode is important to improve DSSC performance. In this paper, to obtain properties of surface and dispersion as nitric acid treated $TiO_2$ photoelectrode was investigate. The photovoltaic characteristics of DSSCs based the electrode fabricated by nitric acid pre-treatment $TiO_2$ materials gave better performances on both of short circuit current density and open circuit voltage. We compare dispersion of $TiO_2$ nanoparticles before and after nitric acid treatment and measured Ti oxidized state from XPS. Low charge transfer resistance was obtained in nitric acid treated sample than that of untreated sample. The dye-sensitized solar cell based on the nitric acid treatment had open-circuit voltage of 0.71 V, a short-circuit current of 15.2 mAcm-2 and an energy conversion efficiency of 6.6 % under light intensity of $100\;mWcm^{-2}$. About 14 % increases in efficiency obtained when the $TiO_2$ electrode was treated by nitric acid.

• 한국학교보건학회지
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• 제12권1호
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• pp.27-44
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• 1999

Obesity in children is a major concern of public health. This study was performed to illuminate its effect on weight control program and the associated factors of obesity-related habits and obesity index in primary school obese children. Weight control program consisted of behavioral modification, nutrition education and exercise during 17 weeks. The sample consisted of treatment group(n=42) and control group(n=41). There was no statistical difference between the two groups in obesity index, socioeconomic status and grade. To assess the effects of weight control program, the subjects were given pre-test and post-test such as the measurement of anthropometric values and self-reporting questionnaire. This result of this study were as follows; 1. After weight control program was applied, there was a significant decrease in obesity index among the treatment group. Obesity-related habits score of the treatment group increased significantly, While there was not much difference between the pre-test and the post-test among the control group. But exercise habit didn't increase significantly in the both groups. 2. Correlation between obesity-related habits and obesity index were not evident. 3. After application of weight control program, the factors associated with change of eating habit were children's past experience of weight control, motivational change toward weight control program and friends' support for treatment group. The factors associated with change of exercise habit were post-test motivation score and friends' support. Motivational change toward weight control and pre-test self-efficacy of exercise behavior were counter-related to exercise habit. For change of other obesity-related habits, initial obesity index, motivational change, post-test self-efficacy score of exercise behavior and paternal educational status were closely associated. But post-test self-efficacy score of eating behavior was unrelated. 4. Only the factor of experience of weight control was associated with change of obesity index. 5. For the both groups, the factors associated with change of eating habits were post-test self-efficacy of eating behavior and family's support. The factors associated with change of exercise behavior were self-efficacy changes of exercise behavior and friends' support. The factors associated with change of other obesity-related habits were self-efficacy change of eating behavior. Initial obesity index was associated with change of obesity index. 6. The rate of dropouts from weight control program was 28.6% (12/42) in treatment group. Initial obesity index, other obesity-related habits except eating exercise habits, friend's support were associated with dropout. In conclusion, these results indicated that weight control program in primary school settings was effective. Direct exercise regimen and practice was demanded. In addition to the program itself, much of the success is dependent on the degree of motivation of the children involved and support provided by their parents and friends. Further study need to be performed under the condition that the weight control progrom is applied for a longer period.

• 대한치과교정학회지
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• 제24권3호
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• pp.649-658
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• 1994

The purpose of this study was to evaluate the association between incisor root resolution and sex, age, extraction, the magnitude and direction of tooth movement. The sample consisted of 189 randomly selected orthodontic patients, receiving standard edgewise orthodontic treatment in three private orthodontic onces at San Francisco. Pre-treatment and post-treatment periapicals and cephalometric radiographs were digitized. Measurements and superimpositions were made utilizing a computerized cephalometric analysis program. The variables were statistically analyzed. The results were as follows: 1. Mean apical root resorption values were $0.77{\pm}2.08mm$ for upper right central incisor, $0.88{\pm}2.11mm$ for upper left central incisor, $-0.05{\pm}2.09mm$ for lower right central incisor and $0.11{\pm}1.85mm$ for lower left central incisor. Apical root resorption of upper incisor was greater than lowers. 2. No correlation was found between sex and apical root resorption. 3. Apical root resorptions in adolescents were smaller than those in adults. 4. Apical root resorption was not affected by extraction. 5. Apical root resorption values of upper incisor were correlated to the horizontal and vertical movement of apex; Apical root resorption values of lower incisor were correlated to the vertical movement of apex.

• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1148-1154
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• 2012

A novel two-phase anaerobic treatment technology was developed to treat high-concentration organic cassava bioethanol wastewater. The start-up process and contribution of organics (COD, total nitrogen, and $NH_4^+$-N) removal in spatial succession of the whole process and spatial microbial diversity changing when sampling were analyzed. The results of the start-up phase showed that the organic loading rate could reach up to $10kg\;COD/m^3d$, with the COD removal rate remaining over 90% after 25 days. The sample results indicated that the contribution of COD removal in the pre-anaerobic and anaerobic phases was 40% and 60%, respectively, with the highest efficiency of 98.5%; TN and $NH_4^+$-N had decreased to 0.05 g/l and 0.90 g/l, respectively, and the mineralization rate of total nitrogen was 94.8%, 76.56% of which was attributed to the anaerobic part. The microbial diversity changed remarkably among different sample points depending on the physiological characteristics of identified strains. Moraxellaceae, Planococcaceae, and Prevotellaceae were dominant in the pre-anaerobic phase and Bacteroidetes, Campylobacterales, Acinetobacter, Lactobacillus, Clostridium, and Bacillus for the anaerobic phase. Methanosarcinaceae and Methanosaeta were the two main phylotypes in the anaerobic reactor.

• Journal of Preventive Medicine and Public Health
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• 제39권2호
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• pp.165-170
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• 2006

Objectives : The determination of oxalate in urine is required for the diagnosis and treatment of primary hyperoxaluria, idiopathic stone disease and various intestinal diseases. We examined the possibility of using Fourier transform near-infrared (FT-NIR) spectroscopy analysis to quantitate urinary oxalate. The practical advantages of this method include ease of the sample preparation and operation technique, the absence of sample pre-treatments, rapid determination and noninvasiveness. Methods : The range of oxalate concentration in standard urine solutions was $0-221mg/{\ell}$. These 80 different samples were scanned in the region of 780-1,300 nm with a 0.5 nm data interval by a Spectrum One NTS FT-NIR spectrometer. PCR, PLSR and MLR regression models were used to calculate and evaluate the calibration equation. Results : The PCR and PLSR calibration models were obtained from the spectral data and they are exactly same. The standard error of estimation (SEE) and the % variance were $10.34mg/{\ell}$ and 97.86%, respectively. After full cross validation of this model, the standard error of estimation was $5,287mg/{\ell}$, which was much smaller than that of the pre-validation. Furthermore, the MCC (multiple correlation coefficient) was 0.998, which was compatible with the 0.923 or 0.999 obtained from the previous enzymatic methods. Conclusions : These results showed that FT-NIR spectroscopy can be used for rapid determination of the concentration of oxalate in human urine samples.

• The Journal of Korean Physical Therapy
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• 제15권3호
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• pp.153-165
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• 2003

This study was carried out to evaluate the body fat breakdown during topical seaweed extract treatment and in combination with the iontophoresis method to enhance skin absorption of lipolytic compounds. Of 14 female obesity subjects, 7 treated a gel types of seaweed extract only(control group) and 7 treated in combination with the iontophoresis(experimental group). Topical treatment of each sample was designed for 2 weeks, treated with 2 times a day about $10m{\ell}$ on the abdomen, triceps and thigh, respectively. Experimental group treat with the iontophoresis during 5 minutes immediately after topical treatment. After one and two weeks of topical treatment, measured body fat, skinfolds thickness, body circumference respectively. Then venous blood samples were taken and analyzed serum lipids. The results were as follows; 1) There were decrement of body weight, $\%$ of body fat, abdomen, triceps and thigh circumference and abdomen, triceps and thigh thickness between pre and post treatment in both group. These decrement were predominant in the iontophoresis treated group. Especially, there were $16\%$ of body fat decrement in the experimental group after two weeks iontophoresis treatment(control group VS experimental group = $33.54{\pm}2.70$ VS $28.37{\pm}3.38$, p<0.01). 2) There were decrement in total CHOL, LDL, TRIG and increment in HDL in both group. These phenomena were predominant in the iontophoresis treated group. CHOL decrement in the experimental group were significant after two weeks iontophoresis treatment(control group VS experimental group = $190.24{\pm}34.36$ VS $157.76{\pm}24.45$, p<0.001). These results suggest that the topical treatment of seaweed extract effective for fat breakdown and maximized in the combination with the topical seaweed extracts treatment and the iontophoresis.

• 정보교육학회논문지
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• 제14권4호
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• pp.555-560
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• 2010

본 연구의 목적은 생활 속에서 알고리즘 개념을 포함하는 사례들을 이용한 알고리즘 학습이 초등학생들의 논리적 사고력에 어떤 영향을 미치는가에 대해 알아 보는 것이다. 이를 위해 사전 GALT 검사, 생활 속에서 알고리즘을 지도할 수 있는 사례 선정 및 지도안 작성후 실험처치, 사후 GALT 검사, 그리고 사전, 사후 GALT 검사 결과 간의 대응 표본 t 검증 순으로 실험을 실시하였다. 그 결과 논리적 사고력의 변화 정도와 논리적 사고력을 구성하는 하위 5 개 영역(보존논리, 비례논리, 조합논리, 확률논리, 변인통제논리)의 변화 정도는 유의수준 .05에서 통계적으로 유의미한 결과를 얻었지만 상관논리 변화 정도는 유의 수준 .05에서 통계적으로 유의미한 결과를 얻지 못하였다.

• Journal of Periodontal and Implant Science
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• 제51권6호
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• pp.433-443
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• 2021

Purpose: This study aimed to evaluate the effectiveness of the partial split-flap technique with a K-incision on vertical guided bone regeneration (vGBR) and to retrospectively analyze the clinical and radiographic outcomes of dental implantation using this approach. Methods: In total, 78 patients who received 104 dental implants with vGBR, categorized as (1) pre-GBR and post-implantation and (2) simultaneous GBR and implantation, were enrolled. Data analysis was based on periapical radiographs, clinical photos, and dental records. The 2-sample t-test was used to compare the 2 surgical procedures. Results: The baseline vertical bone level, augmented bone height (ABH), and treatment duration were significantly higher in the pre-GBR procedure group. The survival rates of the implants were 96.1% and 94.8% in implant- and patient-based analyses, respectively. In Cox regression analysis, high rates of implant failure were found in the presence of ABH of ≥4 mm, smoking, and diabetes. Conclusions: Within the limitations of this retrospective study, the partial split-flap technique using a K-incision for vGBR showed stable clinical outcomes and favorable dental implant survival.

• 유기물자원화
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• 제10권1호
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• pp.87-95
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• 2002

슬러지의 용해율 증가 및 생분해율 향상을 위해 전처리 방법별 처리조건 및 회분, 연속실험을 실시하였다. 용해효과실험에서 SCOD 기준 용해율 효과는 온도무고정 초음파처리(35분)가 가장 높고, 다음으로 알칼리처리(pH13), 열처리($200^{\circ}C$, 30min), 온도고정 초음파처리(60분)순서였다. 초기 회분실험에서 적정 혼합비율은 가스생성량을 기준하여 종오니 : 기질비가 4 : 6일 때(유기물 부하량$3.48kg/m^3{\cdot}day$) 가장 효과적이었다. 회분실험에서 가스발생량은 열처리($200^{\circ}C$, 30min)가 가장 높고, 다음으로 초음파처리(온도 무조정), 알칼리처리(pH9), 초음파처리(온도조정)순서였다. 연속실험은 회분실험에서 가장 효과적인 열처리($200^{\circ}C$, 30min) 시료를 이용하였다. pH는 열처리 (pH 7.2~7.3)가 무처리 (pH 6.9~7.0)시료에 비해 다소 높은 값을 나타내었다. HRT가 길수록 유출수의 pH가 상승하는 경향을 나타내고 있고, 이는 유기물부하의 감소에 따른 생성유기산의 농도저하와 유기산의 가스로의 전환에 의해 생성된 $N_2$가스의 완충작용에 기인한다고 생각된다. 반응조내의 SCOD 농도는 전처리 시료가 무처리에 비해 약 2.5배 높고, 또 HRT는 짧을수록 높았다. 용해성 단백질 및 탄수화물 농도도 전처리 시료가 무처리 시료에 비해 각각 2배 및 3.3배 높았다. 가스 생성량은 열처리시료가 무처리 시료에 비해 약 2배 높아, 열처리가 소화효율 향상에 효과적임을 알 수 있었다. 가스 생성량은 HRT 7day일 때 가장 유리했다. 그러나 HRT 2.5day 일 때 가스 생성량은 무처리 시료에 비해서도 낮은 값을 나타내어 혐기성 세균이 고농도로 축적된 유기산의 저해를 받았기 때문이라고 생각된다.