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A Comparative Study on the Effects of Wearing Reverse Geometry Lenses by Degrees of Myopia (근시정도에 따른 역기하렌즈 착용효과에 관한 비교 연구)

  • Yoon, Min-Hwa;Lee, Ki-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.3
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    • pp.265-272
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    • 2012
  • Purpose: To compare the results on myopia correction with reverse geometry lenses, effects of wearing reverse geometry lenses were evaluated for the children with low-level and high-level myopia. Methods: The research investigated the corrective effects of having worn reverse geometry lenses for one week, one month, three months and six months on a total of thirty-six persons (sixty-two eyes) between the ages of seven and fifteen, divided into three groups by the degree of their myopia; nineteen eyes(Group One) with myopia of -2.00 D and under, twenty-eight eyes(Group Two) with myopia between -2.25 D and -4 D, and fifteen eyes(Group Three) with myopia of -4.25 D and above; as shown by changes in uncorrected vision and the degree of refraction in the corneal topography, and tested for statistical similarity among the pursued results. Results: After wearing reverse geometry lenses, Group One showed an improvement in vision of 0.5, from 0.45 to 0.95, after one week, and improvements to 0.91 after one month and 1.02 after three months but, after six months, the group's vision regressed to 0.95. Group Two showed an improvement in vision of 0.43, from 0.34 to 0.77, after one week of wearing and to 0.91 after one month, to 0.97 after three months and this was statistically maintained through the remainder of six months. Group Three showed an improvement in vision of 0.55, from 0.15 to 0.7, after wearing for one week, to 0.87 after one month and to 0.91 after three months but saw a regression to 0.86 after six months. The average Sim K (simulated keratometry reading) value for Group One started from $42.84{\pm}1.17D$ and decreased to $41.48{\pm}0.98D$ after one week of wearing and continued declining through three months before increasing during the remainder of six months. Group Two began from $42.91{\pm}1.57D$ and recorded $41.78{\pm}1.58 D$ after one week, continuing the decline through three months before increasing during the remainder of six months. Group Three began at $42.64{\pm}1.64D$ and showed its Sim K value decrease to $40.77{\pm}1.20D$ after one week of wearing, increase after one month and decrease after three months and continue the decline through the remainder of six months. Conclusions: From the results of this study, wearing reverse geometry lenses had myopia-correcting effects after one week of wearing. Although there were variations in the time for such effect to take place but myopia-correcting effects were evident in all test groups.

The Neuropsychological Characteristics of the Elementary School Aged Child by 'Computerized Neurocognitive Function Test' ('전산화 신경인지기능검사'를 통한 학령기 정상아동의 신경심리학적 특성)

  • Lee, Jong-Bum;Kim, Jin-Sung;Seo, Wan-Seok;Shin, Hyoun-Jin;Bai, Dai-Seg;Lee, Jun-Heob
    • Korean Journal of Psychosomatic Medicine
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    • v.11 no.2
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    • pp.118-136
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    • 2003
  • Objective: This study is to examine the neuropsychological and developmental characteristics of the Computerized Neurocognitive Function Test among normal children in elementary school. Methods: K-ABC, K-PIC, and Computerized Neurocognitive Function Test were performed to the 120 body of normal children(10 of each male and female) from June, 2002 to January, 2003. Those children had over the average of intelligence and passed the rule out criteria. One-way ANOVA and Bonferroni were used for statistical analysis. Results: In sampling of normal children in elementary school, the control of intelligence level and strict rule out criteria were applied. As a result, although 21.1% were excluded from of total participants, the children that passed the rule out criteria had over the average of intelligence and not differ in the intelligence level among the graders. Comparing Computerized Neurocognitive Function Test results among the graders, almost of variables had significant difference among the graders and especially between the 1st to 2nd and the 5th to 6th graders. In the attention tests, as rising the graders, the performance of tests were improved. In the short-term memory tests, the difference between forward and backward tests were same as the previous research result. The verbal auditory learning test composed of recall task and visual figure memory test composed of recognition task were same as the previous research result using the individual power or achievement test and also as rising the graders, the performance of those tests were improved. The higher cognitive function tests had the same results with other tests. Conclusion: The Computerized Neurocognitive Function Test devised for adult can be used of assessing child neuropsychological characteristics. For this objective, more strict sampling criteria, control of the intelligence and psychopathology were needed.

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Result of Radiation Therapy of Sino-nasal Cancers Using Partial Attenuation Filter (투과성 필터를 이용하여 방사선 치료를 받은 부비동 및 비암의 치료 결과)

  • Kim, Jin-Hee;Kim, Ok-Bae;Choi, Tae-Jin
    • Radiation Oncology Journal
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    • v.25 no.2
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    • pp.118-124
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    • 2007
  • [ $\underline{Purpose}$ ]: This study was to evaluate the survival and pattern of failure after radiation therapy of sino-nasal cancer using partial attenuation filer and wedged beams and to help radiotherapy planning of sino-nasal cancer. $\underline{Materials\;and\;Methods}$: Between February 1992 and March 2003, 17 patients with sino-nasal cancers underwent radiation therapy using partial attenuation filter at Dongsan Medical Center, Keimyung university. There were 9 male and 8 female patients. Patients' age ranged from 40 to 75 years (median 59 years). There were 10 patients of maxillary sinus cancer, 7 patiens of nasal cancer. The histologic type was squamous cell carcinoma in 11, adenoid cystic carcinoma in 4 and olfactory neuroblastoma in 2. The distribution of clinical stage by the AJCC system was 3 for stage II, 7 for III and 6 for IV. The five patients were treated with radiation alone and 12 patients were treated with surgery and postoperative radiation therapy. The range of total radiation dose delivered to the primary tumor was from 44 to 76 Gy (median 60 Gy). The follow-up period ranged from 3 to 173 months with median of 78 months. $\underline{Results}$: The overall 2 year survival rate and disease free survival rate was 76.4%. The 5 year and 10 year survival rate were 76.4% and 45.6% and the 5 year and 10 year disease free survival rate was 70.6%. The 5 year disease free survival rate by treatment modality was 91.6% for postoperative radiation group and 20% for radiation alone group, statistical significance was found by treatment modality (p=0.006). There were no differences in survival by pathology and stage. There were local failure in 5 patients (29%) but no distant failure and no severe complication required surgical intervention. $\underline{Conclusion}$: Radiation therapy of sino-nasal cancer using partial attenuation filter was safe and effective. Combined modality with conservative surgery and radiation therapy was more advisable to achieve loco-regional control in sino-nasal cancer. Also we considered high precision radiation therapy with dose escalation and development of multi-modality treatment to improve local control and survival rate in advanced sino-nasal cancer.

Temporal Variations of Cerebrovascular Diseases in a University Hospital (일개 대학병원을 대상으로 한 뇌혈관질환의 시간적 변동양상)

  • Lee, Mi-Yon;Lee, Sang-Bock;Lee, Jun-Hang;Lee, Sam-Yul;Lee, Tae-Soo;Jin, Gye-Hwan
    • Journal of the Korean Society of Radiology
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    • v.1 no.1
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    • pp.17-23
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    • 2007
  • Background: Cerebrovascular diseases are known to show different patterns of incidence among regions and races. Therefore, it is very important to determine the incidence pattern of a specific area in order to diagnose, treat and prevent cerebrovascular diseases. The objective of the present study is to analyze quantitatively the incidence ratios of hemorrhagic and ischemic cerebrovascular diseases by season, by gender and by age. Methods: The subjects of this study were 1603 patients hospitalized for hemorrhagic or ischemic cerebrovascular diseases at the Department of Neurosurgery or the Department of Neurology of a University Hospital. Statistical analysis of data used Excel 2003 of Microsoft, and t-test was conducted using ORIGIN 6.0 of MICROCAL. Results: In the subjects, the incidence ratios of hemorrhagic and ischemic cerebrovascular diseases for four years, the period of this research, were 38.55% and 61.45%, respectively. The mean and standard deviation of age when hemorrhagic cerebrovascular diseases occurred were 58.20 and 12.60, respectively, and the percentages of subjects in their 40s, 50s, 60s and 70s were all around 20%. On the contrary, the mean and standard deviation of age when ischemic cerebrovascular diseases occurred were 65.01 and 13.59, respectively. The average age of patients with ischemic cerebrovascular diseases was older than that of patients with hemorrhagic brain diseases, and the percentages of those in their 60s, 70s and 80s were 15.53%, 37.06% and 27.72%, respectively. The season when hemorrhagic cerebrovascular diseases appeared most frequently was winter, which was followed by summer, spring and autumn. The season when hemorrhagic cerebrovascular diseases appeared most frequently was spring, which was followed by summer, winter and autumn. Conclusions: In this study, the incidence rates of hemorrhagic and ischemic cerebrovascular diseases were 38.55% and 61.45%, showing the rising percentage of ischemic cerebrovascular diseases. For making adequate prevention and disease control plans, it is considered necessary to make a long-term epidemiological investigation of cerebrovascular diseases.

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A comparative study on the spiritual needs between nursing students and nurses in Busan and Gyeongnam province (부산 경남 지역 간호 대학생과 간호사의 영적 요구도 비교)

  • Cho, Hyun;Sim, Eun-Kyung;Kwon, Young-Chae;Bae, Young-Hee;Woo, Young-Ok;Ji, Jae-Hoon;Jung, Ja-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.5
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    • pp.2178-2188
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    • 2012
  • This study is based upon 200 final responses from a survey conducted for 153 nurses and 147 nursing students in Busan and Gyeongnam province from september to october 2011. It is carried out to compare and understand the spiritual needs of nurses and nursing students that are inclined to be more exposed unhealthy people rather than healthy people. In this study, the level of spiritual care needs was divided into five fields such as 'love and fellowship', 'hope and peace', 'meaning and purpose of life', 'acceptance of death' and 'relationship with God' and was investigated. As a result, the love and fellowship was the highest level in group of nurses (r = 3.82) and the relationship with God was the lowest one (r = 2.73). In contrast, a group of nursing students showed that love and fellowship was the highest level (r = 3.92) and relationship with God was the lowest (r = 2.99) among five fields. There were statistical significances between nurses and nursing students in 'acceptance of death' and 'relationship with God' (p < 0.05). When looking at correlation between fields of spiritual needs of nurses, the correlation between 'meaning and purpose of life' and 'hope and peace' was the highest (r = .699) and the correlation between 'relationship with God' and 'hope and peace' was the lowest (r = .247). As the result of analysis on correlation between fields of spiritual needs of nursing students, the correlation between 'meaning and purpose of life' and 'hope and peace' was the highest (r = .660) and the correlation between 'acceptance of death' and 'relationship with God' was the lowest (r = .277). Therefore, it would be imperative to develop a more efficient and systemized education program for the spiritual care of nursing patients, on the basis of understanding the spiritual needs of nurses and nursing students.

A Study on the Generalization of Multiple Linear Regression Model for Monthly-runoff Estimation (선형회귀모형(線型回歸模型)에 의한 하천(河川) 월(月) 유출량(流出量) 추정(推定)의 일반화(一般化)에 관한 연구(硏究))

  • Kim, Tai Cheol
    • Korean Journal of Agricultural Science
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    • v.7 no.2
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    • pp.131-144
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    • 1980
  • The Linear Regression Model to extend the monthly runoff data in the short-recorded river was proposed by the author in 1979. Here in this study generalization precedure is made to apply that model to any given river basin and to any given station. Lengthier monthly runoff data generated by this generalized model would be useful for water resources assessment and waterworks planning. The results are as follows. 1. This Linear Regression Model which is a transformed water-balance equation attempts to represent the physical properties of the parameters and the time and space varient system in catchment response lumpedly, qualitatively and deductively through the regression coefficients as component grey box, whereas deterministic model deals the foregoings distributedly, quantitatively and inductively through all the integrated processes in the catchment response. This Linear Regression Model would be termed "Statistically deterministic model". 2. Linear regression equations are obtained at four hydrostation in Geum-river basin. Significance test of equations is carried out according to the statistical criterion and shows "Highly" It is recognized th at the regression coefficients of each parameter vary regularly with catchment area increase. Those are: The larger the catchment area, the bigger the loss of precipitation due to interception and detention storage in crease. The larger the catchment area, the bigger the release of baseflow due to catchment slope decrease and storage capacity increase. The larger the catchment area, the bigger the loss of evapotranspiration due to more naked coverage and soil properties. These facts coincide well with hydrological commonsenses. 3. Generalized diagram of regression coefficients is made to follow those commonsenses. By this diagram, Linear Regression Model would be set up for a given river basin and for a given station (Fig.10).

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A Reliability Analysis of Shallow Foundations using a Single-Mode Performance Function (단일형 거동함수에 의한 얕은 기초의 신뢰도 해석 -임해퇴적층의 토성자료를 중심으로-)

  • 김용필;임병조
    • Geotechnical Engineering
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    • v.2 no.1
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    • pp.27-44
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    • 1986
  • The measured soil data are analyzed to the descriptive statistics and classified into the four models of uncorrelated-normal (UNNO), uncorrelated-nonnormal (VNNN), correlatedonnormal(CONN), and correlated-nonnormal(CONN) . This paper presents the comparisons of reliability index and check points using the advanced first-order second-moment method with respect to the four models as well as BASIC Program. A sin91e-mode Performance function is consisted of the basic design variables of bearing capacity and settlements on shallow foundations and input the above analyzed soil informations. The main conclusions obtained in this study are summarized as follows: 1. In the bearing capacity mode, cohesion and bearing-capacity factors by C-U test are accepted for normal and lognormal distribution, respectively, and negatively low correlated to each other. Since the reliability index of the CONN model is the lowest one of the four model, which could be recommended a reliability.based design, whereas the other model might overestimate the geotechnical conditions. 2. In the case of settlements mode, the virgin compression ratio and preccnsolidation pressure are fitted for normal and lognormal distribution, respectively. Constraining settlements to the lower ones computed by deterministic method, The CONN model is the lowest reliability of the four models.

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A Study on Economic Value of Daegu Arboretum based on Contingent Valuation Methods (가상가치평가법을 이용한 대구수목원의 경제적 가치평가)

  • Kang, Kee-Rae;Lee, Kee-Cheol;Lee, Hyun-Taek;Ryu, Byong-Ro;Kim, Dong-Pil
    • Korean Journal of Environment and Ecology
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    • v.25 no.5
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    • pp.787-798
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    • 2011
  • An arboretum is defined as a collection of facilities that conserve plant species by surveying, collecting, and proliferating and preserving the plants in nature, perform diverse researches on plants and display the plants in exhibition spaces or outdoors as well as provide the public with educational programs and refreshment spaces according to the laws concerned. The public, however, recognizes the exhibition and education functions on plants of arboretum more importantly compared with the roles to survey, collect, and proliferate plants as regulated by the laws. In particular, arboretum plays a role to offer a pivotal educational place in urban area where the public can obtain an hands-on experience and understanding on a wide range of plant species and natural environment. The study aims to estimate the non market environmental values of Daegu Arboretum operated by Daegu Metropolitan City government by using the Contingent Valuation Methods (CVM), which yields the current monetary estimates for the arboretum. The value estimation was undertaken by using the Double-Bound Dichotomous Choice (DBDC) method, and each estimated value was derived from respective functions based on a logit distribution known to include relatively stable estimates according to the shape of the distribution. Considering the statistical fitness test results, the author estimated the amounts of the Willingness To Pay (WTP) such as mean WTP of 12,718 KRW, median WTP of 11,033 KRW, and truncated mean WTP of 11,468 KRW, which represented the annual recreational values per a person visiting Daegu Arboretum respectively. The analysis showed that Daegu Arboretum created the annual environmental values which were estimated to be approximately 16 to 19 billion KRW. The study also has an implication that the valuation method for the environment of Daegu Arboretum may be effectively applied for estimating the values of other types of environmental goods by altering the locations or goods to be analyzed.

Optimization of TDA Recycling Process for TDI Residue using Near-critical Hydrolysis Process (근임계수 가수분해 공정을 이용한 TDI 공정 폐기물로부터 TDA 회수 공정 최적화)

  • Han, Joo Hee;Han, Kee Do;Jeong, Chang Mo;Do, Seung Hoe;Sin, Yeong Ho
    • Korean Chemical Engineering Research
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    • v.44 no.6
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    • pp.650-658
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    • 2006
  • The recycling of TDA from solid waste of TDI plant(TDI-R) by near-critical hydrolysis reaction had been studied by means of a statistical design of experiment. The main and interaction effects of process variables had been defined from the experiments in a batch reactor and the correlation equation with process variables for TDA yield had been obtained from the experiments in a continuous pilot plant. It was confirmed that the effects of reaction temperature, catalyst type and concentration, and the weight ratio of water to TDI-R(WR) on TDA yield were significant. TDA yield decreased with increases in reaction temperature and catalyst concentration, and increased with an increase in WR. As a catalyst, NaOH was more effective than $Na_2CO_3$ for TDA yield. The interaction effects between catalyst concentration and temperature, WR and temperature, catalyst type and reaction time on TDA yield had been defined as significant. Although the effect of catalyst concentration on TDA yield at $300^{\circ}C$ as subcritical water was insignificant, the TDA yield decreased with increasing catalyst concentration at $400^{\circ}C$ as supercritical water. On the other hand, the yield increased with an increase in WR at $300^{\circ}C$ but showed negligible effect with WR at $400^{\circ}C$. The optimization of process variables for TDA yield has been explored with a pilot plant for scale-up. The catalyst concentration and WR were selected as process variables with respect to economic feasibility and efficiency. The effects of process variables on TDA yield had been explored by means of central composite design. The TDA yield increased with an increase in catalyst concentration. It showed maximum value at below 2.5 of WR and then decreased with an increase in WR. However, the ratio at which the TDA yield showed a maximum value increased with increasing catalyst concentration. The correlation equation of a quadratic model with catalyst concentration and WR had been obtained by the regression analysis of experimental results in a pilot plant.

Optimization of Supercritical Water Oxidation(SCWO) Process for Decomposing Nitromethane (Nitromethane 분해를 위한 초임계수 산화(SCWO) 공정 최적화)

  • Han, Joo Hee;Jeong, Chang Mo;Do, Seung Hoe;Han, Kee Do;Sin, Yeong Ho
    • Korean Chemical Engineering Research
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    • v.44 no.6
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    • pp.659-668
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    • 2006
  • The optimization of supercritical water oxidation (SCWO) process for decomposing nitromethane was studied by means of a design of experiments. The optimum operating region for the SCWO process to minimize COD and T-N of treated water was obtained in a lab scale unit. The authors had compared the results from a SCWO pilot plant with those from a lab scale system to explore the problems of scale-up of SCWO process. The COD and T-N in treated waters were selected as key process output variables (KPOV) for optimization, and the reaction temperature (Temp) and the mole ratio of nitromethane to ammonium hydroxide (NAR) were selected as key process input variables (KPIV) through the preliminary tests. The central composite design as a statistical design of experiments was applied to the optimization, and the experimental results were analyzed by means of the response surface method. From the main effects analysis, it was declared that COD of treated water steeply decreased with increasing Temp but slightly decreased with an increase in NAR, and T-N decreased with increasing both Temp and NAR. At lower Temp as $420{\sim}430^{\circ}C$, the T-N steeply decreased with an increase in NAR, however its variation was negligible at higher Temp above $450^{\circ}C$. The regression equations for COD and T-N were obtained as quadratic models with coded Temp and NAR, and they were confirmed with coefficient of determination ($r^2$) and normality of standardized residuals. The optimum operating region was defined as Temp $450-460^{\circ}C$ and NAR 1.03-1.08 by the intersection area of COD < 2 mg/L and T-N < 40 mg/L with regression equations and considering corrosion prevention. To confirm the optimization results and investigate the scale-up problems of SCWO process, the nitromethane was decomposed in a pilot plant. The experimental results from a SCWO pilot plant were compared with regression equations of COD and T-N, respectively. The results of COD and T-N from a pilot plant could be predicted well with regression equations which were derived in a lab scale SCWO system, although the errors of pilot plant data were larger than lab ones. The predictabilities were confirmed by the parity plots and the normality analyses of standardized residuals.