• Journal of Gastric Cancer
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• v.4 no.3
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• pp.156-163
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• 2004

Purpose: While E-cadherin in normal cells induces calciumdependent cell-cell adhesion, in malignant cell, it plays a role in invasion and metastasis with a reduction of adhesion. Serum soluble E-cadherin is a result of the reduction of the cellular E-cadherin molecule and is found in the circulation of normal individuals, but it is particularly known to be increased in patients with malignancies. Accordingly, through checking the level of serum soluble E-cadherin in patients with gastric cancer and analyzing it in the view of clinicopathology, we investigated whether serum soluble E-cadherin could be translated into a clinicopathologic esult and used as a tumor marker. Materials and Methods: The investigation targeted 88 patients who had been diagnosed as having gastric cancer by the Department of Surgery, St. Mary's Hospital, from October 1, 2002, to July 30, 2003, and who had under gone performed surgery. We measured the level of preoperative serum E-cadherin in the 88 patients by unsing ELISA. Among them, we collected gastric cancer tissues from 54 patients and executed immunohistochemistry for E-cadherin. The samples were compared with normal tissues in terms of both serum E-cadherin level and immunohistochemistry level, as well as with other clinicopathologic factors. Result: The mean serum E-cadherin level of the 88 patients was 4368.7 ng/ml and was significantly higher than the level in 12 normal control patients, 3335.5 ng/ml (P=0.016). In terms of clinicopathology, the serum level of E-cadherin was significantly correlated with increasing age (P=0.0006) and was higher in positive venous invasion patients (P=0.0005). When the E-cadherin immunohistochemical stain was compared with the serum E-cadherin level in 54 patients, no significant statistically meaningful result was obtained (P=0.2881). However, 4 patients with serum E-cadherin levels about 6000 ng/ml were classified into the lower expression group ($<80\%$ of E-cadherin immunohistochemicals stain. In the analysis for 36 patients who were early gastric cancer patients, the serum E-cadherin level in lymph-node-metastatic patients was higher than it was in the other patients (P=0.0442). Conclusion: The serum E-cadherin level in gastric cancer patients was higher than the level in normal control patients. In advanced gastric cancer patients, that the difference was increased. Also, since the E-cadherin level correlated with the serum E-cadherin level with venous invasion, it can be used as an effective tumor marker for gastric cancer. Particularly, in that the serum E-cadherin level correlated with lymph node metastasis in early gastic cancer, it can be used when a therapeutic method for early gastric cancer is selected.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.207-214
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• 2009

Purpose: Subtotal distal gastrectomy has been accepted as the standard treatment for early gastric cancer that's developed on the gastric body. EMR and ESD have been introduced to minimize the incidence of postgastrectomy syndrome, but these procedures can not detect lymph node metastasis and they have a risk for gastric perforation. Segmental gastrectomy has recently been applied for treating early gastric cancer, but its usefulness has not been clarified. The aim of this study was to compare segmental gastrectomy and distal gastrectomy with Billroth I reconstruction for treating early gastric cancer that's developed on the gastric body. Materials and Methods: We performed a retrospective review of all the patients who were diagnosed as having early gastric cancer that developed on the gastric body at Chungnam National University Hospital from January 2004 through July 2007. During this period, 41 patients received segmental gastrectomy and 40 patients underwent subtotal distal gastrectomy. All the patients were studied via a biannual review of the body systems, a physical examination, endoscopy, computed tomography and the laboratory findings. Results: There were no significantly differences of the clinicopathologic characteristics between the two groups. The changes of the nutritional status (Hb, TP, Alb and TC) and the body weight change were not significantly different between the 2 groups. There were significantly more residual food in the SG group than that in the SDG group (RGB classification, Residual>Grade 2), but there were no differences for epigastric discomfort (P>0.05). Esophagitis developed at a similar rate for both two groups (LA classification, >Grade A), and bile reflux was found in only one patient of each group. Conclusion: We expected the reduction of esophagitis and gastritis and the improvement of nutritional status according to the type of procedure. Yet the results of our study showed no significant differences between the two study groups. More patients and a longer follow up time are needed for determining the advantage sand disadvantages of segmental gastrectomy.

• Journal of Gastric Cancer
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• v.13 no.3
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• pp.164-171
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• 2013

Purpose: Laparoscopy-assisted distal gastrectomy for early gastric cancer has gained acceptance and popularity worldwide. However, laparoscopy-assisted distal gastrectomy for advanced gastric cancer is still controversial. Therefore, we propose this prospective randomized controlled multi-center trial in order to evaluate the safety and feasibility of laparoscopy assisted D2-gastrectomy for advanced stage gastric cancer. Materials and Methods: Patients undergoing distal gastrectomy for advanced gastric cancer staged cT2/3/4 cN0/1/2/3a cM0 by endoscopy and computed tomography are eligible for enrollment after giving their informed consent. Patients will be randomized either to laparoscopyassisted distal gastrectomy or open distal gastrectomy. Sample size calculation revealed that 102 patients are to be included per treatment arm. The primary endpoint is the non-compliance rate of D2 dissection; relevant secondary endpoints are three-year disease free survival, surgical and postoperative complications, hospital stay and unanimity rate of D2 dissection evaluated by reviewing the intraoperative video documentation. Discussion: Oncologic safety is the major concern regarding laparoscopy-assisted distal gastrectomy for advanced gastric cancer. Therefore, the non-compliance rate of clearing the N2 area was chosen as the most important parameter for the technical feasibility of the laparoscopic procedure. Furthermore, surgical quality will be carefully reviewed, that is, three independent experts will review the video records and score with a check list. For a long-term result, disease free survival is considered a secondary endpoint for this trial. This study will offer promising evidence of the feasibility and safety of Laparoscopy-assisted distal gastrectomy for advanced gastric cancer. Trial Registration: NCT01088204 (international), NCCCTS-09-448 (Korea).

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.863-870
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• 2016

We investigated the physical/chemical phenomena that a slow loss of $CO_2$ inventory into sodium after the sodium-$CO_2$ boundary failure in printed circuit heat exchangers (PCHEs), which is considered for the supercritical $CO_2$ Brayton cycle power conversion system of a sodium-cooled fast reactor (SFR). The first phenomenon is plugging inside narrow sodium channels by micro cracks and the other one is damage propagation referred to as wastage combined with the corrosion/erosion effect. Experimental results of plugging shows that sodium flow immediately stopped as $CO_2$ was injected through the nozzle at $300{\sim}400^{\circ}C$ in 3 mmID sodium channels, whereas sodium flow stopped about 60 min after $CO_2$ injection in 5 mmID sodium channels. These results imply that if pressure boundary of sodium-$CO_2$ fails a narrow sodium channel would be plugged by reaction products in a short time whereas a relatively wider sodium channel would be plugged with higher concentration of reaction products. Wastage by the erosion effect of $CO_2$ (200~250 bar) hardly occurred regardless of the kinds of materials (stainless steel 316, Inconel 600, and 9Cr-1Mo steel), temperature ($400{\sim}500^{\circ}C$), or the diameter of the $CO_2$ nozzle (0.2~0.8 mm). Velocities at the $CO_2$ nozzle were specified as Mach 0.4~0.7. Our experimental results are expected to be used for determining the design parameters of PCHEs for their safeties.

• KDI Journal of Economic Policy
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• v.12 no.1
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• pp.93-110
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• 1990

The basic purpose behind the Korean government's policy toward the Korean deep sea fishing industry is to limit growth of the industry. Therefore, the regulations on the industry are generally restrictive and interventionist. The policy is intended to maintain high domestic fish prices in order to protect the domestic coastal fishing industry. Some regulations have also been introduced to maintain "industrial order." Each fishing vessel must obtain a government permit for operation. The permit specifies the kind of fish it can catch, the area of sea in which it can operate, and the port at which it can unload its catches. The number of permits government issues each year is based on the estimates of the demand increase calculated by government officials, and the government traditionally has been fairly conservative in its estimation, reflecting its concern for fish price stabilization, which actually implies a gradual increase of the prices. There is also a restriction on importing vessels from abroad. This regulation is intended to protect the domestic shipbuilding industry. However, this regulation has resulted in an unusually high average age of Korean fishing vessels, causing fishing costs to rise. These regulations and the inflexible response of the regulators to changing circumstances have resulted in many problems: i) high domestic fish prices, which are, to some extent deliberately, inflated to three or four times the level of international prices, resulting in huge consumer welfare losses; ii) over-exploitation of coastal fish resources; iii) provision of a hospitable environment for inefficient firms to survive, which is especially evident from the fact that, despite the high fish prices in Korea, most of the firms in the industry do not enjoy high profitability. It also must be pointed out that the actual beneficiaries of the high fish prices are the large operators, who are protected from competition and provide most of the fish for domestic consumption, rather than the low-income fishing households and small coastal operators whom the policy was originally designed to help. This study proposes a set of regulatory reforms and policy changes which could Promote competition and equity within the industry and allow firms to reduce costs and increase productivity. Such changes can make the industry more efficient and internationally competitive. Major proposals are, among others: minimization of bureaucratic discretion in issuing fishing permits and maintaining transparency in the governments' decision-making processes; reduction of the government permit specifications and simplification of the operational categories within the industry; and removal of the restrictions on importing foreign fishing vessels.

• KDI Journal of Economic Policy
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• v.12 no.1
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• pp.111-125
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• 1990

For the last several years, considerable criticism has been leveled against Korea's exchange rate management. While Korea was designated a currency manipulator by the U.S., domestically it is often complained that the won/dollar rate did not adequately reflect changes in Korea's export competitiveness and fluctuations in the exchange rates of major currencies. In view of this situation, Korea changed its exchange regime at the beginning of March this year from the dual currency basket system to a more flexible one, called a "market average rate regime". Under this new regime, the won rate is determined in the exchange market based upon the supply of and demand for foreign exchange and is allowed to freely fluctuate each day within a + 0.4 % range. This paper, first, seeks to evaluate Korea's exchange rate management under the dual basket regime of the 1980s, and then to construct an optimal currency basket for the won which could provide a proper indicator for exchange market intervention under the new market average rate regime. The analysis of fluctuations in the real effective exchange rate (REER) of the won indicates that the won rates in the 1980s failed not only to offset changes in relative prices between home and trading partner countries, but also to properly respond to variations in major exchange rates as further evidenced by sizable fluctuations in the nominal effective rates of the won. In other words, the currency basket regime which was adopted in 1980 for the stabilization of the REER of the won has not been operated properly, mainly because authorities often resorted to policy considerations in determining the won's rate. In the second part of the paper, an optimal currency basket for Korea is constructed, designed to minimize the fluctuations in the REER of the won without including policy considerations as a factor. It is recognized, however, that both domestic and foreign price data are not available immediately for the calculation of the REER. For this problem, the approach suggested by Lipschitz (1980) is followed, in which optimal weights for currencies in the basket are determined based upon the past correlation between price and exchange rates. When the optimal basket is applied to Korea since the mid-80s, it is found that the REER of the won could have been much more stable than it actually was. We also argue for the use of variable weights rather than fixed ones, which would be determined by the changing relationship between exchange rates and relative prices. The optimal basket, and the optimal basket exchange rate based on that basket, could provide an important medium- or long-term reference for proper exchange market intervention under the market average rate regime, together with other factors, such as developments in the current account balance and changes in productivity.

• Journal of Technologic Dentistry
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• v.23 no.2
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• pp.121-149
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• 2002

This Study aims at investigating the tendency of individual problems that the students at the departments of dental technology are faced with, their efforts and types of activities to solve the problems. Surveyed for this purpose were 700 freshmen to juniors enrolled in the departments of dental technology at the universities across the country and they were analyzed by area, grade and sex. 1. Tendency of Problems The areas of problems the students at the departments of dental technology considered as most serious were health, human relation, view of value and economy in sequence, while the areas they considered as least serious were future course and employment. In general, there were tendencies as follows: divided by grade, the higher the grades of the students are, the higher scores of problems they get(F=12.14, P=.000) : in the areas of health and human relation, as the grade gets higher, the scores of their problems also increase, accordingly(F= 17.58, P=.000)(F=8.39, P=.000) : in the areas of economy, parents and home, freshmen and juniors are found to have higher scores of problems compared to sophomores,:F=7.89, P=.000)(F=11.63, P=.000) : divided by sex, female students recorded higher scores of problems than their counterparts(F=31.85, P=.000) 2. Efforts for Problems View of value, human relation, parents and home appeared to be the areas for which the students made the highest rate of efforts in sequence while the areas for which they paid lowest grade of efforts were health and economy. In other words, the students gave higher scores for human relation and view of value in terms of tendency as well as efforts of problems, while they rated high for health and economy in the tendency but low in the efforts of problems. Divided by grade, freshmen and juniors appeared to score higher points than sophomores in their efforts to solve problems, even though juniors made relatively higher efforts than freshmen(F=6.53, P=.002). Divided by sex, female students scored higher points in their efforts than males(F=15.98, P=.000) 3. Difference of Efforts to Solve Problems. In the analysis into the scores of difference showing the disagreement between the tendency of problems and the efforts to solve problems, the area of health was rated as highest, followed by economy. There was little difference of scores between human relation and view of value, an indicator of agreement between the scores of problems and efforts. The difference of scores between future course and employment, between liberal arts and recreation, between characters/parents and home/school work turned out to be negative in the listed sequence, leading to a conclusion that the students enrolled in the departments of dental technology are making more efforts to solve problems than actually needed in most areas. By grade, there was a significant difference only in the area of health(F=3.00, P=.050). This difference itself was widening as the students come to higher grades. By sex, females showed bigger difference than males. 4. Types of Activities to Solve Problems. The analysis into types of activities to solve problems revealed that the surveyed students seemed to actively cope with the problems in all areas, relying at the same time on personal relationship. Especially in the areas of health, economy, parents, home, human relation, future course and employment, the students appeared to deal with the problems actively as well as emotionally.

• The Korean Journal of Elementary Counseling
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• v.5 no.1
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• pp.227-253
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• 2006

It seems common for students living at a small county and islands to experience psychological conflicts and be unaccustomed in the peer society because they are not familiar with peer interaction and social skills. This is a case study of L (hereinafter called L) who was grown up in the sheltered school at a small county. L was psychologically disturbed because he couldn't get along well in the transferred school. It is the reason why he had lived in the sheltered school at a small county, so he had not enough exposure to interact with peer and social skills. Sometimes he was obstinate irrationally and when he had trouble with friends, he threw something out or went out of school and tricked juniors dangerously. The fact of disperse with families, parent's indifference, and hate of older brother made L to have ill feeling against family. He had low motivation and low self confident in learning because of short attention time and accumulated poor learning progress. In this study, he was evaluated at various area, such as, intelligent, affective, personal and inter-personal, before counselling. To evaluated the effect of the counselling, K-WISC-III, KPRC, sentence filling test, social adaptation ability test, etc, were administered right after the counselling was over and 8 weeks later. For specific information gathering and analysing, observation diary and deepen counselling were accomplished by homeroom teacher, his mother, and his peers. To correct his problematic behaviors, 13 counseling sessions were accomplished for 6 months and those counselling sessions were recorded and analysed definitely. Followings are the result of this case study. First, he was recovered from the anxiety of inter-personal interaction and he started to interact with peers. The result of sac scale score of KPRC profile was lower than before as much as average student after counseling and 8 weeks later. This reveals that the distress against interpersonal relation have settled. Especially, through the result of sentence filing test, he seemed to feel attachment to peers and be positive, active in the relation of peer. For instance, he was active in the open class lesson and interacted well with peers. It could be said that he overcame the psychological distress comparing with previous time. Second, he could apologize to his peer and juniors for his fault. His attitude were well shown in the letter from an old friend at the sheltered school, average KPRC profiling score comparing with previous counseling time, and remarkable decrease of attack scale score of teacher and peer. Third, his view toward family turn out positive. He recognized his situation that he lived apart from family and even worried about his parent's financial difficulty. Through solving the confliction with his older brother, he could acquire the feeling of family reunion. Fourth, his learning motivation and self-confidence were increased. He confirmed his future positively and he might be judged more attentive because his intelligence index was higher than before as much as average student. With the main goal of this study, verification for effectiveness of counseling. understanding and helping problematic students such as L who lives at a small county and island through investigation of their real situation and problems with the method of counseling and socio-cultural analysis is worthwhile. Identification of ideal relationship with peer is related with positive self-conception, harmonic social adaptation and development of child. It is time to investigate easy adaptive in classroom and well-organised program to acquire general social skills for sheltered school students at a small county and islands.

• The Korean Journal of Elementary Counseling
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• v.5 no.1
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• pp.65-92
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• 2006

The objective of this study is to conduct survey analyses of the role perception and performance of homeroom teachers in elementary schools in Seoul as well as their students' expectations for teachers' role as counsellors. The study also aims to analyze the causes behind the lackluster performance, to provide assistance in teachers' counselling and guidance activities and collect basic data for providing a plausible orientation for elementary school counselling. Research topics for achieving these study objectives are as follows. First, what is the status quo of counselling between elementary school students and teachers? Second, what is the role perception of elementary school homeroom teachers as counsellors and their current level of performance? Third, what are the differences in students' expectations for homeroom teachers' role as counsellors according to students' environmental variables such as gender and grade? Fourth, what are the discrepancies between the roles perception and performance of elementary school homeroom teachers and role expectation of students for homeroom teachers' role as counsellors? In order to answer these questions, surveys were conducted for 229 teachers and 385 students in grades 4, 5 and 6 in 11 elementary schools in Seoul, and the results were analyzed. The questionnaires used for this study were modified and supplemented according to the research objectives based on survey questions released by Gyung-Beom Lee(1989), Hak-Soo Lee(2001) and Gi-Nam Gwon(2005). Statistical analyses were peformed using the SPSS for Windows 10.0 program. The results of the study can be summarized as follows. First, most elementary school homeroom teachers were involved in counselling activities, and about half of them were providing counselling once a month or less. The classroom was the primary location of counselling, and more than half of the surveyed teachers were dissatisfied with their counselling activities. The teachers cited overwhelming teaching hours and excessive work as the factors that made counselling difficult. Second, it was revealed that most elementary school students have had experiences of anguish and most have had some form of counselling. They mostly sought counselling from their parents and friends, and the reasons behind such choices were that they were very understanding. Third, most students responded that they have had no experience of receiving counselling from their homeroom teachers. Among those with counselling experience with their homeroom teachers, most said that the counselling was helpful. The most significant reason for not receiving counselling from their homeroom teachers was that the students had no worries to talk about with their teachers. Fourth, as a result of categorizing the role of elementary school homeroom teachers as counsellors according to the areas of counselling, role perception for each area turned out to be generally high, while performance was substantially lacking. Fifth, in terms of the causes for the lackluster counselling performance, overwhelming teaching hours and excessive work were indicated for counselling areas of academic and personality issues. Sixth, the analysis of students' expectations for elementary school homeroom teachers as counsellors for counselling areas according to gender and grade revealed that there was no overall statistical significance. Seventh, from the general perspective, the level of role perception of the homeroom teachers were higher than the level of students' expectations. In conclusion, in order to enhance the teacher's role as a counsellor, there has to be a concrete perception of roles as a primary premise, calling for training sessions and programs dedicated to counseling for the teachers to take part in. Moreover, in order to alleviate the most significant causes for undermining teachers' counselling activities - overwhelming teaching hours and excessive work - there must be administrative consideration as well as provisions for effective counselling centers and dedicated school counsellors.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.2
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• pp.161-170
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• 1997

This is an effort to confirm changes biological monitoring according to changes in levels of exposure to styrene for industrial workers. This study was conducted on 108 workers, including male of 64 and female 44 who were working at factories of FRP, dipping, and coating. An improved passive monitor method(organic vapor monitor; OVM) was employed to determine levels of exposure. The biological monitoring include blood styrene concentration, urinary mandelic acid(MA), and urinary phenylglyoxylic acid(PGA). Biological monitoring were made through the Collection of blood and urine. The mean value of exposure to styrene was 21.0ppm, which is measured by organic vapor monitor, one of improved passive monitors. The highest exposure level was observed among workers in boat factories, laminating procedure workers, processing workers, respectively(p<0.01). For exposure level, 11% of subjects under study showed over 50ppm which is time weighted average(TWA). The correlation coefficient between biological specimens and the exposure level was 0.62 for blood styrene concentration, 0.58 for MA corrected by creatinine, and 0.70 for PGA corrected by creatinine, respectively(p<0.01). The regression analyses found exposure level relative importance in explaining variance in biological monitoring. In additional to that, gender was a significant factor in explaining variance of MA and MA+PGA. Almost half of variance(49%) in blood styrene concentration was explained by predictors, including exposure level, age, gender, duration, and drinking volume during the last week(p<0.01). The very high correlation(higher than 0.95 was found when a comparison was made among three types of corrected methods, including uncorrected specific gravity and creatinine. In conclusion, these findings suggest OVM to represent levels of exposure to styrene for industrial workers. A discussion was made on possible use of specific gravity sample for biological monitoring. Exposure level may be predicted on MA, PGA in urine, which could be applied to represent biological monitoring.