• The Korean Journal of Nuclear Medicine
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• v.35 no.5
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• pp.334-341
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• 2001

Purpose: Ascorbic acid us known to act as an antioxidant. Therefore, it can be used in increasing the efficiency of radiochemical labeling of Technetium-99m setamibi by inhibition of oxidation of $Sn^{2+}$ at low concentration. We intended to estimate the efficiency of radiochemical labeling and the stability of the newly formed formulation when ascorbic acid was added to a commercial kit. Materials and Methods: Synthesis of sestamibi was performed according to Dong-A's patent procedure (No.10-2001-0012877). First, we undertook a study to evaluate the efficiency of radiochemical labeling of sestamibi containing ascorbic acid. The stability of the vials was assessed using either $7.5{\mu}g\;or\;75{\mu}g$ of ascorbic acid, added to commercial vials under the accelerated condition(Temp : $40^{\circ}C{\pm}2^{\circ}C$, Relative humidity : $75{\pm}5%$). Results: Sestamibi was synthesized in overall 35-40% yield over 5 steps from a commercially available methallyl chloride as a starling material. When ascorbic acid was added, the efficiency of radiochemical labeling was maintained compared to the vial with no ascorbic acid. The accelerated test showed that the addition of ascorbic acid inhibited the oxidation of $Sn^{2+}$ ion by antioxidation mechanism. Also, the efficiency of radiochemical labeling of this vial after 9 months was nearly the same as the starting point. Therefore, the storage period of the kit is likely to be extended. Taken together, it suggests that the addition of ascorbic acid as a stabilizer is desirable. Conclusion: To increase the stability of a sestamibi cold kit, it is desirable to add ascorbic acid as a stabilizer to the commercial formulation.

• Korea journal of population studies
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• v.10 no.2
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• pp.17-45
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• 1987

This study contributes to understanding women's labor market behavior by focusing on a particular set of labor force transitions - labor force withdrawal and entry during the period surrounding the first birth of a child. In particular, this study provides a dynamic analyses, using longitudinal data and event history analysis, to conceptualize labor force behaviors in a straightforward way. The main research question addresses which factors increase or decrease the hazard rates of leaving and entering the labor market. This study used piecewise Gompertz model, following the guide of the non-parametric analysis on the hazard rates, which allowed relatively detailed description on the distribution of timing of leave and entry to the labor market as parameters of interest. The results show that preferences and structural variables, as well as economic considerations, are very important factors to explain the labor market behavior of women in the period surrounding childbirth.

• The KIPS Transactions:PartB
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• v.11B no.6
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• pp.749-758
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• 2004

In this paper, we propose a new method utilizing only raw corpus without additional human effort for disambiguation of target word selection in English-Korean machine translation. We use two data-driven techniques; one is the Latent Semantic Analysis(LSA) and the other the Probabilistic Latent Semantic Analysis(PLSA). These two techniques can represent complex semantic structures in given contexts like text passages. We construct linguistic semantic knowledge by using the two techniques and use the knowledge for target word selection in English-Korean machine translation. For target word selection, we utilize a grammatical relationship stored in a dictionary. We use k- nearest neighbor learning algorithm for the resolution of data sparseness Problem in target word selection and estimate the distance between instances based on these models. In experiments, we use TREC data of AP news for construction of latent semantic space and Wail Street Journal corpus for evaluation of target word selection. Through the Latent Semantic Analysis methods, the accuracy of target word selection has improved over 10% and PLSA has showed better accuracy than LSA method. finally we have showed the relatedness between the accuracy and two important factors ; one is dimensionality of latent space and k value of k-NT learning by using correlation calculation.

• Neonatal Medicine
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• v.16 no.1
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• pp.55-63
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• 2009

Purpose: This study was conducted to investigate the incidence and clinical manifestations of rotaviral infections in the neonatal intensive care unit (NICU). We also investigated whether neonates referred from other hospitals cause outbreaks of rotaviral infections in the NICU. Methods: Neonates diagnosed wit rotaviral infections in the NICU at Korea University Ansan Hospital between January 2002 and December 2006 were evaluated retrospectively. Results: Of 1,501 neonates admitted to the NICU, the number of rotaviral infections was 94 (6.3%) and the prevalence was 4.9 cases per 1,000-hospital days. Of 223 neonates referred from other hospitals to our NICU, 24 (10.8%) were confirmed to have rotaviral infections at the time of referral. Common symptoms of rotaviral infections were jaundice diarrhea or loose stools, vomiting, fever, apnea, irritability, seizures, and moaning sounds. Necrotizing enterocolitis of stage II or more was diagnosed in 3 premature neonates, accounting for 3.2% of total infected neonates and 6.8% of premature infected patients. There were no statistically significant differences in the prevalence of symptoms between term and preterm neonates, except for jaundice that is more frequent in premature infants. In time series analysis, the admission of neonates who were born at other hospitals and diagnosed with rotaviral infections were associated 1 month later by increased cases of neonates with rotaviral infections who were born at our hospital, whereas new cases of rotaviral infections among inborn neonates were decreased 2 and 4 months later (P<0.05). Conclusion: Rotaviral infections in NICU were not rare and showed vague symptoms. Three cases (3.2%) were diagnosed with stage II or more necrotizing enterocolitis. The referred neonates with rotaviral infections may induce outbreaks in the NICU, therefore awareness and strict surveillance for rotaviral infections should be performed at the time of referral.

• Korean Journal of Cognitive Science
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• v.28 no.3
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• pp.149-171
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• 2017

In this research, based on the fact that spatial ability is important for the achievement in the STEM fields, and technological innovation, Purdue Spatial Visualization Test-Rotation has been used to investigate engineering freshmen's spatial ability and gender differences. Students who have taken advanced mathematics courses in high school(those who have taken type B math test in Korean SAT test) and students with general math courses(those who have taken type A in Korean SAT-Math test) are included in this study to find out the relationship between mathematics achievement and spatial ability. Finding out the strategies taken by students was another aim of this study. This strategic differences between high achievers and lower achievers, male and female students were analyzed from students' self report. Spatial ability test score was highest in the SAT-Math type B male students, decreased in the order of type A male students, type B female students, and lastly type A female students. There was no substantial difference between second and third groups. In each group, male students' average score was 8~10% higher than female students, which affirms 2015's results. The correlation between spatial ability and mathematics achievement was negligible in each group, but male students' math score and spatial ability score were higher than that of female students. This can be interpreted that there is some correlation between these two. Strategic choices can vary in the continuous spectrum with analytic method and holistic method at both ends. From students' self report, using Mann-Witney test, it turned out that there exists strategic differences between male and female students. Male students have a tendency to use holistic strategy more often than female students. I also found that the strategy choice did not vary greatly among all score groups. For the perfect score groups, both female and male students used holistic strategy most frequently. For low achieving groups, there is an evidence that these students overuse one method compared to average or high achieving groups, which turned out to be less effective. Based on these, I suggest that low achieving students need to have more chances to adopt efficient strategies and to practice challenging problems to improve their spatial abilities.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.3
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• pp.192-207
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• 2006

Today, the SSL protocol has been used as core part in various computing environments or security systems. But, the SSL protocol has several problems, because of the rigidity on operating. First, SSL protocol brings considerable burden to the CPU utilization so that performance of the security service in encryption transaction is lowered because it encrypts all data which is transferred between a server and a client. Second, SSL protocol can be vulnerable for cryptanalysis due to the key in fixed algorithm being used. Third, it is difficult to add and use another new cryptography algorithms. Finally. it is difficult for developers to learn use cryptography API(Application Program Interface) for the SSL protocol. Hence, we need to cover these problems, and, at the same time, we need the secure and comfortable method to operate the SSL protocol and to handle the efficient data. In this paper, we propose the SSL component which is designed and implemented using CBD(Component Based Development) concept to satisfy these requirements. The SSL component provides not only data encryption services like the SSL protocol but also convenient APIs for the developer unfamiliar with security. Further, the SSL component can improve the productivity and give reduce development cost. Because the SSL component can be reused. Also, in case of that new algorithms are added or algorithms are changed, it Is compatible and easy to interlock. SSL Component works the SSL protocol service in application layer. First of all, we take out the requirements, and then, we design and implement the SSL Component, confidentiality and integrity component, which support the SSL component, dependently. These all mentioned components are implemented by EJB, it can provide the efficient data handling when data is encrypted/decrypted by choosing the data. Also, it improves the usability by choosing data and mechanism as user intend. In conclusion, as we test and evaluate these component, SSL component is more usable and efficient than existing SSL protocol, because the increase rate of processing time for SSL component is lower that SSL protocol's.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.87-95
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• 2015

Purpose : This study presents the usefulness assessment of secondary shield for the lens exposure dose reduction during radiation treatment of peripheral orbit. Materials and Methods : We accomplished IMRT treatment plan similar with a real one through the computed treatment planning system after CT simulation using human phantom. For the secondary shield, we used Pb plate (thickness 3mm, diameter 25mm) and 3 mm tungsten eye-shield block. And we compared lens dose using OSLD between on TPS and on simulation. Also, we irradiated 200 MU(6 MV, SPD(Source to Phantom Distance)=100 cm, $F{\cdot}S\;5{\times}5cm$) on a 5cm acrylic phantom using the secondary shielding material of same condition, 3mm Pb and tungsten eye-shield block. And we carried out the same experiment using 8cm Pb block to limit effect of leakage & transmitted radiation out of irradiation field. We attached OSLD with a 1cm away from the field at the side of phantom and applied a 3mm bolus equivalent to the thickness of eyelid. Results : Using human phantom, the Lens dose on IMRT treatment plan is 315.9cGy and the real measurement value is 216.7cGy. And after secondary shield using 3mm Pb plate and tungsten eye-shield block, each lens dose is 234.3, 224.1 cGy. The result of a experiment using acrylic phantom, each value is 5.24, 5.42 and 5.39 cGy in case of no block, 3mm Pb plate and tungsten eye-shield block. Applying O.S.B out of the field, each value is 1.79, 2.00 and 2.02 cGy in case of no block, 3mm Pb plate and tungsten eye-shield block. Conclusion : When secondary shielding material is used to protect critical organ while irradiating photon, high atomic number material (like metal) that is near by critical organ can be cause of dose increase according to treatment region and beam direction because head leakage and collimator & MLC transmitted radiation are exist even if it's out of the field. The attempt of secondary shield for the decrease of exposure dose was meaningful, but untested attempt can have a reverse effect. So, a preliminary inspection through Q.A must be necessary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.223-233
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• 2013

The purpose of this study was to analyze the dietary habits and perception of vegetable intake of elementary students in Gwangju and Jeonnam Gokseong county. Data collection was conducted from 5th and 6th grade students of elementary schools in Gwangju and Jeonnam Gokseong county using a structured questionnaire survey. The SPSS program was used for statistics processing and data analysis. The chi-square test was also conducted. In terms of dietary intake habits, female students consumed their meals slower than male students. Information on dietary habits and nutrition was commonly obtained from family, including the mother or father who commonly prepared meals at home. Snacks were commonly consumed less than twice daily, with the Gwangju area having a higher frequency of snacks than the Jeonnam area. Elementary students indicated that vegetables were their least favorite food, with female students having a higher interest in vegetables than male students. The pattern and perception of vegetable intake came when the students (that did not eat vegetables) were lectured by their parents on the nutritive value of vegetables. Most students understood the important nutritional ingredients of vegetables. In the case of an interest in vegetables, the Gwangju area showed significantly more comprehension than the Jeonnam area on the definition and role of dietary fiber, the dental benefits of dietary fiber, and the identification of the environment-friendly certification mark.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.123-127
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• 1987

The Pungent principles and Essential oil compositions of Zanthoxylum piperitum $D_E$ $C_{ANDOLIE}$(peel, barb) were analysed by HPLC and GC, respectively. Total Pungent principle contents of peels were about as 12 times as those of barks. The Sanshool I, Sanshool IV, Sanshool III and Sanshoo V were the major Pungent principles in the peels and barks. Besides, several Unknown Pungent principles were discovered in the peels and barks, too. Total Essential oil contents of peels were higher than those of barks at the ratio of 1.8 % to 0.5%. The Cineol+Limonene(37.7%) were the main Essential oil compositions in the peels, while ${\alpha}-Terpineol(16.5%)$ and Pinene(15.5%) were the major portion in the barks. The Essential oil of peels and barks were composed Pinen, Myrcene, Cineol+Limonene, Linalool, Isopulegol, Terpinen-4-ol, ${\alpha}-Terpineol$ and Piperitone. Besides, seven Unknown compositions were discovered, too.

• Journal of Gastric Cancer
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• v.6 no.2
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• pp.76-83
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• 2006

Purpose: Endoscopic incision and submucosal dissection (EISD) is a technique that is being implemented for the resection of gastric adenomas and early gastric cancer (EGC). Since EISD requires a high degree of skill and experience, and due to its association with a moderate risk of gastrointestinal bleeding, its use has been limited. The objective of this study is to investigate the clinical benefits of EISD based upon clinical data on the EISD procedure. Materials and Methods: This study was conducted at Soonchunhyang University Hospital and it included 179 gastric adenoma and early gastric carcinoma lesions from 164 patients who had undergone an EISD from February 2003 to May 2005. Results: Among the total of 179 lesions, the distributions of EGC and adenomas were 70.3% (126/179) and 23.4% (42/179) respectively. The sizes of lesions were divided into 10 mm or less, $11{\sim}20\;mm,\;21{\sim}30\;mm$ and greater than 31 mm and each rates are 10.0% (18/179), 46.3% (83/179), 30% (50/179) and 15.0% (28/179). Among 120 cases which could be measured depth of lesion in according to pathologic findings, m1 (0.8%, 1/120), m2 (38.3%, 46/120), m3 (25%, 57/120), sm1 (11.7%, 14/120), sm2 (1.6%, 2/120) were diagnosed as early stages of gastric cancer. The complete resection rate was 85.2% (150/176) and en-bloc resection rate was 96.0% (169/176). Complications as such as perforation and bleeding developed in 4.4%(8/179) and 21.2% (38/179), respectively. Conclusion: EISD is an effective in the endoscopic treatment for gastric adenoma and early gastric cancers. However, further evaluation of this method and long-term follow-up will be necessary for an evaluation of the recurrence rate after resection of a tumor.