• 한국방사선학회논문지
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• 제9권3호
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• pp.139-145
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• 2015

SPECT를 이용한 환자의 검사 시 몸 안에서 방출되는 ${\gamma}$-선은 감쇠 또는 산란 등의 현상이 일어나며, 검출기에 도달할 때 조준기의 물리적 특성과 기학적인 모양에 따라 퍼지는 현상이 발생하여 정량분석이 불가능하였다. 체내에서 방출되는 ${\gamma}$-선의 정확한 정량분석을 위해서는 반드시 부분용적효과에 대한 보정이 고려되어야 한다. 본 논문에서는 SPECT의 종합적인 부분용적효과를 해결하기 위하여 Sinogram Filter를 구현하였다. 구현된 Filter를 적용하여 실험을 한 결과, SPECT에서 발생되는 부분용적효과를 제거하였다. 기존방법과 제안한 방법을 비교하기 위하여 PSNR을 시행한 결과 제안한 방법으로 한 경우 PSNR은 7 dB, 기존방법은 14 dB로 나왔다. 제안한 방법의 dB이 낮아진 이유는 산란선 제거를 많이 하여 MSE가 높아지기 때문에 PSNR값이 낮게 나타났다. 따라서 제안한 방법을 적용한다면 SPECT 영상의 부분용적효과를 제거하여 영상의 질이 좋아질 것이다.

• Journal of Biosystems Engineering
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• 제37권2호
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• pp.113-121
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• 2012

Purpose: Particle separation in solution is one of important process in a unit operation as well as in an extract preparation for biosensors. Contrary to centrifuge-type of mesh-type filter, using an ultrasonic standing wave make the filtering process continuous and free from maintenance. It is needed to investigate the characteristics of particle movement in the ultrasonic standing wave field. Methods: Through the computer simulation the effects of major design and driving parameters on the alignment characteristics of particles were investigated, and a cylindrical chamber with up-stream flow type was devised using two circular-shape PZTs on both sides of the chamber, one for transmitting ultrasonic wave and the other for just reflecting it. Then, the system performance was experimentally investigated as well. Results: The speed of a particle to reach pressure-node plane increased as the acoustic pressure and size of particle increased. The maximum allowable up-stream flow rate could be calculated as well. As expected, exact numbers of pressure-node planes were well formed at specific locations according to the wavelength of ultrasonic wave. As the driving frequency of PZT got close to its resonance frequency, the bands of particles were observed clearer, which meant the particles were trapped into narrower space. Higher excitation voltages to the PZT produced a greater acoustic force with which to trap particles in the pressure-node planes, so that the particles gathered could move upwards without disturbing their alignments even at a higher inlet flow rate. Conclusions: This research showed the feasibility of particle separation in solution in the continuous way by an ultrasonic standing wave. Further study is needed to develop a device to collect or harvest those separated particles.

• 분석과학
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• 제8권4호
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• pp.759-770
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• 1995

By extensive studies with the quantitative status of the mineral constituents of thousands of water samples, it was found that almost in all natural waters irrespective of the surface or sub-surface sources, minimum 99.5% of the total amount of the cationic constituents are generally the contributions of 3 commonly present parameters viz. Ca, Mg and Na and that of the anionic species are same and contributed by $HCO_3$, Cl and $SO_4$ only. In the field of water works, all these major mineral substances are conventionally measured as their individual ions. But till now, no reliable and generalised methods or rules have been developed for the determination of the exact kinds of the individual salt components and their amounts from these ionic constituents normally present in water. As salt content, only the TDS (Total Dissolved Solids) parameter is frequently measured by evaporation of the water sample. But TDS can tell nothing about the kinds and amounts of the individual salts present in it. Considering the analytical importance of the estimation of the mineral substances as their individual salts, some generalised mathematical models have been developed by this research which are based on the 'hypothetical order of chemical combinations' as may occur among the ionic constituents. With the help of these models, one can easily assume the most probable salts with approximate quantities derived from the ionic constituents. In addition, approximate amount of Na content can also be estimated mathematically with simultaneous verification of the correctness of the water analysis results. The models are stated in this paper with practical illustrations and descriptions of the method of applications.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제8권6호
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• pp.669-678
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• 2002

최근 시각 관련 측정기 개발에 대한 국내의 관심이 높아지고 있다. 이에 본 논문은 자동 시각 굴절력 곡률계의 전자 부문 소프트웨어와 하드웨어 시스템을 개발하였다. 광학 부문으로부터 나오는 영상 을 이용하여 전자 부문 시스템에서 내부 처리를 거친 후 정확한 시각 측정치를 검사자에게 알려 줄 수 있다면 잘못 측정되는 측정 횟수를 잠재적으로 크게 줄일 수 있을 것이다. 전자 부문 시스템은 소프트웨어와 하드웨어의 두 부분으로 나뉘어 개발되었는데, 소프트웨어 부분은 형태학적 필터링과 그레이 레벨의 신호 강조 기술 등을 이용하여 행해짐으로써, 보다 향상된 굴절력 치수를 도출할 수 있게 개발하였고, 하드웨어 부분은 기존의 시스템들과 동일한 기능을 수행함과 동시에 하드웨어의 변경 없이도 소프트웨어의 변경을 자유롭게 행할 수 있도록 구성하여 개발기간을 크게 줄일 수 있고 나아가 응용 확장 등도 용이하다는 장점을 가지게 되었다. 그리하여 전자 부문 시스템은 정확한 측정값 도출이 어려운 시각 영상에 적용되어 효과적으로 오차를 줄임으로써 보다 효율적인 시각 측정을 가능하게 하였다.

• Restorative Dentistry and Endodontics
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• 제39권3호
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• pp.201-209
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• 2014

Objectives: This study evaluated the solubility, dimensional alteration, pH, electrical conductivity, and radiopacity of root perforation sealer materials. Materials and Methods: For the pH test, the samples were immersed in distilled water for different periods of time. Then, the samples were retained in plastic recipients, and the electrical conductivity of the solution was measured. The solubility, dimensional alteration, and radiopacity properties were evaluated according to Specification No. 57 of the American National Standards Institute/American Dental Association (ANSI/ADA). Statistical analyses were carried out using analysis of variance (ANOVA) and Tukey's test at a significance level of 5%. When the sample distribution was not normal, a nonparametric ANOVA was performed with a Kruskal-Wallis test (${\alpha}$ = 0.05). Results: The results showed that white structural Portland cement (PC) had the highest solubility, while mineral trioxide aggregate (MTA)-based cements, ProRoot MTA (Dentsply-Tulsa Dental) and MTA BIO ($\hat{A}$ngelus Ind. Prod.), had the lowest values. MTA BIO showed the lowest dimensional alteration values and white PC presented the highest values. No differences among the tested materials were observed in the the pH and electrical conductivity analyses. Only the MTA-based cements met the ANSI/ADA recommendations regarding radiopacity, overcoming the three steps of the aluminum step wedge. Conclusions: On the basis of these results, we concluded that the values of solubility and dimensional alteration of the materials were in accordance with the ANSI/ADA specifications. PCs did not fulfill the ANSI/ADA requirements regarding radiopacity. No differences were observed among the materials with respect to the pH and electrical conductivity analyses.

• 한국치위생학회지
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• 제16권1호
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• pp.27-35
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• 2016

Objectives: The purpose of the study was to find out dental caries and periodontal disease based on oral healthcare of adults in Busan. This study will provide the preventive oral healthcare for the periodontal diseases and dental caries. Methods: The study subjects were 369 people from the regular dental health checkup in the general hospital in Busan. After receiving informed consent, a self-reported questionnaire was completed from October 1, 2014 to January 31, 2015. The questionnaire consisted of dental caries and periodontal diseases by direct examination and toothbrushing method. Data were analyzed by ${\chi}^2$ test, Fisher's exact test, and Pearson's correlation. Results: In the morbidity of dental caries and periodontal diseases, the dental caries was most common in those having restored teeth(236 subjects, 64%), while periodontal diseases were found in mild cases of gingival inflammation in 285 subjects(77.2%), and mild cases of dental calculus in 274 subjects(73.4%). Most of the respondents replied that they did not have systemic disease or oral health related symptoms. According to toothbrushing pattern, dental caries experiences were most common in those having less frequent toothbrushing less than 3 minutes and no tongue brushing. The outbreak of dental caries was more common in 5 times than 3 to 4 times a day. Conclusions: The education of the right toothbrushing method and use of dental floss is the most important prevention of dental caries and periodontal disease in the adults.

• 한국치위생학회지
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• 제15권6호
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• pp.1019-1026
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• 2015

Objectives: The purpose of the study is to investigate the influence of elderly-related experience on attitude toward elderly in dental hygiene students. Methods: A self-reported questionnaire was completed by 213 dental hygiene students in Suwon from November 21 to 30, 2012. The questionnaire consisted of general characteristics of the subjects, elderly-related experience, knowledge on elderly, and attitude toward elderly by Likert 7 points scale. The instrument for knowledge on elderly was adapted from facts on aging quiz-I by Palmore and modified by Kim et al. Data were analyzed by t test, one way ANOVA, and multiple regression analysis using SPSS 21.0 program. Results: The attitude toward the elderly was $2.79{\pm}0.42$. The elderly-related experience had a positive influence on the attitude toward elderly(p=0.019) according to the level of experiencing the elderly(r=0.161, p<0.05). The influence of elderly-related experience on attitude toward the elderly showed that an experiencing variable is key factor in predicted variable of the attitude toward the elderly(${\beta}$=0.177 p=0.015). Conclusions: Elderly-related experience had an effect on positive attitude toward the elderly people in the dental hygiene students. It is necessary to develop and implement the education program for the exact knowledge and attitude toward the elderly.

• 대한유전성대사질환학회지
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• 제12권2호
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• pp.94-98
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• 2012

Purpose: Developmental delay and mental retardation are frequently occurring disorders that present major socio-economic burden on the affected individual's family and society. Both can be congenital or acquired. However, a large number of people are institutionalized without exact diagnosis and, as a result, have not received proper care. Methods: 508 subjects with mental retardation or developmental delay from six institutions in Chung Buk Province were clinically evaluated and screened for metabolic and endocrinologic problems between 2000 and 2012. Results: Clinical genetic disorders were observed in 52 (10.2%) subjects. Cerebral palsy attributed to 21% of the institutionalized. 18 (3.5%) were diagnosed with metabolic disorders and 13 (2.6%) exhibited secondary endocrinologic dysfunction. Over 16% showed metabolic evidence of malnutrition. Conclusion: 21% and 3.5% of the population institutionalized due to mental retardation or developmental delay were afflicted by preventable cerebral palsy and metabolic disorders, respectively. Through early identification of the causes and early treatment, it may be possible to prevent, reduce, or alleviate the disability of many institutionalized individuals. Further research is imperative for establishing guidelines for diagnostic investigation for mental retardation.

• 대한약침학회지
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• 제20권3호
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• pp.201-206
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• 2017

Objectives: The aim of this study was to investigate the effects of Cassia acutifolia on the obesity and the glucose levels in a rat model of obesity and diabetes. Methods: By random selection, 36 Wistar male rats were divided in two control groups, the positive and the negative control groups, and into four experimental groups receiving different infusions of Cassia acutifolia in water ad libitum. Results: The results revealed a statistically significant anti-obesogenic effect (P = 0.02), although this was not considered clinically significant. Additionally, Cassia acutifolia lowered the glucose levels by 30 mg/dL to 90 mg/dL (P = 0.05). However, we observed adverse effects in the liver, a two-fold increase in transaminase levels (P = 0.002), and in the kidneys, decreased creatinine levels (P = 0.001), and these adverse effects had no viable explanation. Conclusion: Cassia acutifolia has anti-hyperglycemic effects in obese diabetic rats. However, Cassia acutifolia also has adverse effects, so it should not be administered to patients.

• 생명과학회지
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• 제20권6호
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• pp.955-959
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• 2010

아시아조충과 무구조충의 편절은 형태학적으로 유사해 감별진단하기가 쉽지 않다. 하지만 아시아조충의 경우 감염자에서 낭미충증 등의 심각한 합병증을 일으킬 가능성을 배제할 수 없으므로 두 기생충의 정확한 진단이 필요하다. 최근 기생충학 분야에서 DNA 서열에 기초한 진단 방법이 널리 쓰이고 있다. 본 연구에서는 다중 중합 효소연쇄반응을 이용해 한국인에서 발견된 태니아 속 조충류의 감별진단을 시도해 보고자 했다. 중합효소연쇄반응을 위해 Ta4978F, Ts5058F, Tso7421F, Rev7915 4개의 시발체(프라이머)를 사용했으며, 그 결과 태니아의 종 동정이 정확하고 신속하게 이루어질 수 있었다. 중합효소연쇄반응 방법을 도입한다면 한국에서 인체 태니아 조충의 역학적 소견을 용이하게 재검토할 수 있으리라고 생각한다.