• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.377-382
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• 2014

Purpose: To investigate the effect of anterior, posterior corneal astigmatism and total corneal astigmatism on posterior corneal astigmatism by analyzing correlation. Methods: Participants were 31 patients (31 eyes) without corneal disease at the age range of 22 to 28 who had visited hospital to receive corneal refractive surgery. The total corneal astigmatism and anterior and posterior corneal astigmatism were measured using a rotating scheimpflug camera before surgery. The magnitude of astigmatism was calculated with the difference between the meridian of the steep refractive power and the flat, and With-The-Rule and inverse astigmatism were divided according to the direction of the meridian that was the steepest. Results: The averages of total corneal astigmatism and anterior and posterior astigmatism were found to be $1.13{\pm}0.76D$, $1.51{\pm}0.84D$, and $-0.59{\pm}0.17D$. The magnitude of posterior corneal astigmatism was distributed between -1.0 D and -0.25 D in all the subjects, and when the magnitude of total corneal astigmatism was set as 100, the magnitude of anterior corneal astigmatism was $142.9{\pm}29.9%$. Total corneal astigmatism indicated the highest correlation with the magnitude of anterior astigmatism (y = 0.871x-0.184, $R^2=0.982$) and high negative correlation with posterior astigmatism (y = -2.974x-0.184, $R^2=0.698$). All the subjects' anterior and posterior corneal astigmatism was classified into With-The-Rule. Conclusions: Anterior and posterior corneal astigmatism in the subjects in their 20's showed the magnitude of -3.8 D in 0.2 D and -0.25 D in -1.0 D separately, and both anterior and posterior astigmatism indicated a high percentage of With-The-Rule.

• The Korean Journal of Applied Statistics
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• v.14 no.2
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• pp.345-355
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• 2001

동일한 유효성분을 가지면서 용량 혹은 형식 만이 다른 제제의 개발이 증가되고 이에 따른 두 제제 이상의 생물학적 동등성시험의 필요성이 제기되었다. 이에 이용주 등(1998)은 온단세트론 제제에 대한 생물학적 동등시험에서 3$\times$3 교차설계법을 적용하였다. 그러나 3$\times$3 교차설계법에서 각 순서에 피험자의 수가 다르거나 실험중에 결락(dropout)되는 피험자가 발생하는 경우에는 일반적인 통계적 방법은 적용할 수 없었다. 본 연구에서는 이러한 경우에 제제효과의 추론에 대한 통계적 방법과 생물학적 동등성 시험 방법을 제안하고 모의실험을 통하여 생물학적 동등성평가의 정도를 측정하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.97-101
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• 2009

Purpose: To assess the refractive state of the westerners (male: 44, female: 62) in twenties who visited the A optical shop at Seoul. Methods: The visual acuity test was performed by the objective and subjective method. Results: The emmetropia and myoptia were 35 and 177 eyes (83.49%), respectively. About 26.76% of tested males was ametropia. Myopia compound and myopia simple astigmatism were found in 60.56% and 12.68% of tested males, respectively. However, about 43.40% of tested females was ametropia. Myopia compound and myopia simple astigmatism were 49.06% and 7.55% were found in tested females, respectively. As for the equivalent spheric power of myopic abnormal refractive eyes, the -0.5D < spheric equivalent ${\leq}$ -2.00D was 35.02% of tested westerners, the -2.00D < spheric equivalent ${\leq}$ -6.00D was 60.45% and anything over the -6.00D was 4.53%. The percentages of with-the-rule, against-the-rule and oblique astigmatism among people with astigmatism were 59.82%, 26.78% and 13.40%, respectively. The average of pupillary distance in male (63.5${\pm}$2.4 mm) was greater than that in female (59.7${\pm}$2.3 mm). Conclusions: Korean opticians were provided some useful information about making up a prescription for the westerners in twenties by this research.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.115-118
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• 2012

Purpose: The Levey-Jennings chart controlled measurement values that deviated from the tolerance value (mean ${\pm}2SD$ or ${\pm}3SD$). On the other hand, the upgraded Westgard Multi-Rules are actively recommended as a more efficient, specialized form of hospital certification in relation to Internal Quality Control. To apply Westgard Multi-Rules in quality control, credible quality control substance and target value are required. However, as physical examinations commonly use quality control substances provided within the test kit, there are many difficulties presented in the calculation of target value in relation to frequent changes in concentration value and insufficient credibility of quality control substance. This study attempts to improve the professionalism and credibility of quality control by applying Westgard Multi-Rules and calculating credible target value by using a commercialized quality control substance. Materials and Methods : This study used Immunoassay Plus Control Level 1, 2, 3 of Company B as the quality control substance of Total T3, which is the thyroid test implemented at the relevant hospital. Target value was established as the mean value of 295 cases collected for 1 month, excluding values that deviated from ${\pm}2SD$. The hospital quality control calculation program was used to enter target value. 12s, 22s, 13s, 2 of 32s, R4s, 41s, $10\bar{x}$, 7T of Westgard Multi-Rules were applied in the Total T3 experiment, which was conducted 194 times for 20 days in August. Based on the applied rules, this study classified data into random error and systemic error for analysis. Results: Quality control substances 1, 2, and 3 were each established as 84.2 ng/$dl$, 156.7 ng/$dl$, 242.4 ng/$dl$ for target values of Total T3, with the standard deviation established as 11.22 ng/$dl$, 14.52 ng/$dl$, 14.52 ng/$dl$ respectively. According to error type analysis achieved after applying Westgard Multi-Rules based on established target values, the following results were obtained for Random error, 12s was analyzed 48 times, 13s was analyzed 13 times, R4s was analyzed 6 times, for Systemic error, 22s was analyzed 10 times, 41s was analyzed 11 times, 2 of 32s was analyzed 17 times, $10\bar{x}$ was analyzed 10 times, and 7T was not applied. For uncontrollable Random error types, the entire experimental process was rechecked and greater emphasis was placed on re-testing. For controllable Systemic error types, this study searched the cause of error, recorded the relevant cause in the action form and reported the information to the Internal Quality Control committee if necessary. Conclusions : This study applied Westgard Multi-Rules by using commercialized substance as quality control substance and establishing target values. In result, precise analysis of Random error and Systemic error was achieved through the analysis of 12s, 22s, 13s, 2 of 32s, R4s, 41s, $10\bar{x}$, 7T rules. Furthermore, ideal quality control was achieved through analysis conducted on all data presented within the range of ${\pm}3SD$. In this regard, it can be said that the quality control method formed based on the systematic application of Westgard Multi-Rules is more effective than the Levey-Jennings chart and can maximize error detection.

• Journal of the Ergonomics Society of Korea
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• v.14 no.1
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• pp.97-104
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• 1995

The widespread use of VDU has improved the efficiency of information transmission between man and machine, but has caused new occupational health and ergonomics problems. In this study, we tried to construct a fuzzy hyman performance model of VDU workers in Korea. Fuzzy inferences of human perfor- mance are obtained from the fuzzy inference rule with the job difficulty, CFF, SACL, Type A. and the degree of concentration in VDU work. Eight healthy female undergraduate students at Kyungnam university for subjects aged 20 to 23 years were examined in this experiment. They calculated continuous addition, subtraction, and multiplication of 1 or 2 digit numbers that were produced randomly on the CRT. Subjects peoformed two types of a numeric operation, which easy and difficult work produced 400 and 600 problems within a 40 minute work session, respectively. Subjects were tested over two workdays according to the type of work(easy and difficult) consisting of four 40 minutes work sessions in the morning. Each work lasted for five minutes with a ten minutes rest break. 117 fuzzy inference rules were obtained from the experimental data. The value of consequent part was obtained by a descent method. The difference between real human error and estimated value of fuzzy inference was $1.8075{\pm}1.8591%(M{\pm}SD)$. The difference in easy and diffcult works were $2.69{\pm}2.13%$ and $0.92{\pm}0.93%$, respectively.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.147-152
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• 1996

his study was undertaken to assess the residual interventricular shunt following surgical closure of the isolated ventricular septal defect. From January 1989 through December 1993, 211 patients underwent surgical closure of the isolated ventricular septal defect. All patients had 2D-Echocardlo-graphic study after operation to rule out residual ventricular septal defect. There was a 9.5% incidence of a definite residual shunt. The type of ventricular septal defect, closure method of the defect and cardiopulmonary bypass time showed no significant differences between two groups. The sue of ventricular septal defect (6.3 $\pm$ 3.7mm versus 10.6 $\pm$ 5.8mm : p : 0.0034), aortic cross-clamping time(32.6 $\pm$ 15.0 minutes versus 48.5 $\pm$ 20.0 minutes, p : 0.0003), pulmonary-to-systemic pressure ratio(0.31 $\pm$ 0.22 versus 0.51 $\pm$ 0.33, p=0.019) and mean pulmonary artery pressure(20.3 $\pm$ 11.9 mmHg versus 29.1 $\pm$ 16.2 mmHg, p : 0.009) were meaningfully different between two groups. There were 9 insta ces of spontaneous closure of the residual shunts at mean 21 months of following up (ranged 1 ~43 months). In conclusion, we suggest that the size of ventricular septal defect, aortic cross-clamping time and mean pulmonary artery pressure may play an important role in occurance of residual ventricular septal defect.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.113-117
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• 2008

Purpose: This study is to survey that uncomfortable feeling of visual acuity in the first wearing glasses, the number of visiting in age, above vision ranging and refractive errors, astigmatism, and anisometropia. Methods: Automatic refraction and naked visual acuity test executed to receive prescription glasses that the man 509 and women's 499 people visited for the first time, among 3~15 years old who visited an ophthalmoiogical hospital, from January to December, 2003. Results: The first wearing glasses started 3 years old and the most cases was 8~9 years old when they were visited visual acuity 0.5 to 0.7 in most cases. Refractive errors appeared 8 years old and its most plentifully with 20.4%, 92.2% was myopia and 5.2% was hyperopia for the man. Also cases of women was 91.9% for myopia and 5.1% for the hyperopia. Spherical equivalent power was S-1.50${\pm}$1.10D and appeared 62.3% for the low myopia. Astigmatism was appeared 44.6% for the with the rule astigmatism and 75% was cylinder power lower than 1.00D. Cases of simple astigmatism need to glass when was cylinder power C-1.37${\pm}$1.01D, and C-0.50D appeared most distribution. More than 2.00D anisometropia appeared 2.3% for the whole subjective. Conclusions: Of the first wearing glasses visual acuity is 0.5~0.7, spherical equivalent power is S-1.50${\pm}$1.10D, cylinder power of simple astigmatism is C-1.37${\pm}$1.01D.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.485-490
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• 2014

The purpose of this Study investigated corneal power, corneal astigmatism and corneal axis according to spherical equivalent of refractive error. We measured spherical equivalent, corneal power and corneal astigmatism in 100 subjects from January 2014 to July 2014. Measured spherical equivalent of refractive error were $-3.01{\pm}3.79D$, corneal power of $43.79{\pm}1.60D$ and corneal astigmatism of $-1.17{\pm}0.79D$ respectively. Prevalence of spherical equivalent of refractive error were as follows : myopes (61%), emmetropes (22%), hyperopes(17%). Corneal astigmatism of refractive error greater than +0.75D was 63% and prevalence of corneal astigmatism were as follows : with-the-rlue astigmatism (84.13%), against-the-rule astigmatism(9.52%) respectively. Corneal power by spherical equivalent increased from hyperopia to myopia. Between spherical equivalent of refractive error and the mean corneal power was significant correlation(r=-0.25, p=0.01). A correlation were found between corneal power and spherical equivalent of refractive error in adults. They have the highest distribution of prevalence myopia among the refractive error. When the refractive error was increased, we found that corneal power was steeper. It is recognized that this can be refractive error factor and correct visual function is considered.

• Advances in pediatric surgery
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• v.7 no.2
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• pp.95-104
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• 2001

Biliary atresia (BA) is very difficult to distinguish from neonatal hepatitis (NH) and its prognosis depends on the age at the time of Kasai operation. Therefore early differentiation between these two conditions is very important. Although various clinical and laboratory tests have been reported to differentiate between them, they are still of limited value. From 1980 to 1999, forty-five infants were referred to our pediatric surgical unit for operation for suspected BA. Eight patients underwent Kasai operation immediately because of late diagnosis. These were excluded from the study. The clinical history, physical findings. radiologic and laboratory examinations of 37 cases were analyzed retrospectively. The average age of BA (n=20) was $55.1{\pm}16.7$ days, and that of NH (n=17) was $55.8{\pm}15.6$ days. The sex ratio of BA was 13:7, and that of NH was 14:3. All the patients had obstructive jaundice and acholic stool except 4 BA and 6 NH patients. Acholic stool with yellow component was more frequent in NH. Onset of jaundice was within 2 weeks after birth in 85 % of BA, and in 65% of NH. The onset of acholic stool was within 2 weeks after birth in 60 % of BA, and in 23.5 % of NH. The duration of jaundice and acholic stool of BA were $50.9{\pm}16.6$ days and $41.3{\pm}18.4$ days and those of NH were $40.1{\pm}23.1$ days and $26.6{\pm}25.4$ days respectively. The ultrasonogram and hepatobiliary scan were useful, but not a definitively reliable method for the differentiation of these two diseases. There was no difference in laboratory data. Seventeen cases had NH among 45 referred cases for Kasai operation with the clinical impression of BA, and 4 cases of 17 NH cases needed to be explored to rule out BA. In conclusion. false positive rate of clinical impression of BA was 37.8 %. and negative exploration rate was 8.9 %, Therefore. careful clinical observation for 1-2 weeks by an experienced pediatric surgeon was very important to avoid unnecessary operation to rule out NH up to the age of 8 - 10 weeks. so long as the stool had yellow component.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.35-39
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• 2016

To conduct a kinetic study of paraquat (PQ), we investigated 9 patients with acute PQ intoxication. All of them ingested more than 20 ml of undiluted PQ herbicide to commit suicide and arrived at our hospital early, not later than 7 h after PQ ingestion. The urine dithionite test for PQ in all of the nine patients was strongly positive at emergency room. Blood samples were obtained every 30 min for the first 2~3 h and then every 1 or 2 h, as long as the clinical progression was stable among the patients for 30 h after PQ ingestion. The area under the plasma concentration-time curve ($AUC_{inf}$), which was extrapolated to infinity, was calculated using the trapezoidal rule. Toxicokinetic parameters, such as the terminal elimination half-life, apparent oral clearance, and apparent volume of distribution ($V_d/F$) were calculated. The maximum PQ concentration ($C_{max}$) and the time to reach maximum PQ concentration ($T_{max}$) were also obtained. Plasma PQ concentrations in nine patients were well described by a bi-exponential curve with a mean terminal elimination half-life of $13.1{\pm}6.8h$. $C_{max}$ and $AUC_{inf}$ were $20.8{\pm}25.7mg/l$ and $172.5{\pm}160.3h{\cdot}mg/l$, respectively. Apparent volume of distribution and apparent oral clearance were $50.9{\pm}61.3l/kg$ and $173.4{\pm}111.2l/h$, respectively. There were a significant correlation (r=0.84; p<0.05) between the PQ amount ingested and $C_{max}$. $AUC_{inf}$ also showed a significant correlation (r=0.83; p<0.05) with the PQ amount ingested. These correlations provide evidence that PQ has dose-linear toxicokinetic characteristics.