• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.4
• /
• pp.419-430
• /
• 2007

Purpose: This in vitro study evaluated shear bond strengths of surface treatment porcelains with four porcelain repair systems simulating intraoral bonding of composite resin to feldspathic porcelain or pressable porcelain. Material and methods: Eighty Porcelain disks were prepared. Group A: forty disk specimens were fabricated with Feldspathic Porcelain($Omega^{(R)}900$, Vident, Menlo Park, CA, USA). Group B: forty disk specimens were fabricated with Pressable Porcelain(IPS Empress 2 ingot, Ivoclar-Vivadent, Schaan, Liechtenstein, Germany). Each groups was divided into 4 subgroups and composite resin cylinders were bonded to specimen with one of the following four systems: Clearfil Porcelain Bond(L. Morita, Tustin, CA, USA), Ulradent Porcelain Etch. (Ultradent, Salt Lake City UT, USA), Porcelain Liner-M(Sun Medical Co., Kyoto, Japan), Cimara Kit(Voco, Germany). After surface conditioning with one of the four porcelain repair systems substrate surfaces of the specimen were examined microscopically(SEM). Shear bond strengths of specimens for each subgroup were determined with a universal testing machine (5mm/min crosshead speed) after storing them in distilled water at $37{\pm}1^{\circ}C$ for 24 hours. Stress at failure was measured in $MP_a$, and mode of failure was recorded. Differences among four repair systems were analyzed with two way ANOVA and Duncan test at the 95% significance level. Results: In the scanning electron photomicrograph of the treated porcelain surface, hydrofluoric acid etched group appeared the highest roughness. The shear bond strength of the phosphoric acid etched group was not significantly(p>0.05) different between feldspathic porcelain and pressable porcelain. But in no treatment and roughened with a bur group, the shear bond strength of the feldspathic porcelain was significantly higher than that of the pressable porcelain. In hydrofluoric acid etched group, the shear bond strength of the pressable porcelain was significantly higher(p<0.05). Conclusion: 1. Treatment groups showed significantly greater shear bond strengths than no treatment group(p<0.05). 2. Group with more roughened porcelain surface did not always show higher shear bond strengths. 3. In phosphoric acid etched group, there was no significant difference in shear bond strength between feldspathic porcelain and pressable porcelain(p>0.05). However in the other groups, there were significant differences in shear bond strengths between feldspathic porcelain and pressable porcelain(p<0.05).

• Journal of Science and Technology Studies
• /
• v.14 no.1
• /
• pp.139-175
• /
• 2014

For the past 20 years, expert groups and citizens in Korea have debated on the usefulness of personalized medicine. These debates were mainly focussed on the possibility of the promise - people mainly discussed whether it was a probable future or if it was just a hype. Following Hedgecoe and Tutton(2002) who argue that it is only a 'rhetorial device', we will analyze about 9,000 news media coverages that deal with personalized medicine. With these data, we will show that the same terminology of personalized medicine have been used very differently according to the time and people who use it. Our research will show that this term has both diachronic heterogeneity and synchronic equivocality. This has happened because of the innate lack that exists in our symbolic system. Policy and governance regarding new technology is important because they provide quilting point to those slippery term/signifiant. Also we would like to carefully suggest that we might be able to call this phenomena as signifiant-politics.

• Journal of the Korea Concrete Institute
• /
• v.14 no.6
• /
• pp.973-981
• /
• 2002

Recently, the use of high strength concrete (HSC) has increased dramatically md however, few studies have been conducted on the early-age properties of HSC such as setting. The penetration resistance test (specified by KS F 2436) that is the standard test method for determining initial and final setting times of concrete, may not be appropriate for HSC because of the high viscosity of the mortar mixture. To address this issue, an ultrasonic pulse velocity (UPV) monitoring system was used to investigate the setting behavior of mortar and concrete. The experimental study was carried out to measure the UPV's of mortars and concretes having various water/binder ratios (W/B) and various fly ash replacement levels, during the first 24 hours of testing. Test results showed that the UPV in concrete was developed faster than that of mortar with the same W/B, and that of ordinary concrete was greater than that of fly ash concrete. Typical values of UPV were suggested that correspond to the initial and final setting times, based on following criteria: (1) the penetration resistance method; (2) the instant when the UPV begins to develop; and (3) the instant when the UPV development rate is maximum. The method and UPV monitoring device used in this study is promising for the setting assessment of concrete, particularly for HSC.

• Journal of electromagnetic engineering and science
• /
• v.15 no.3
• /
• pp.142-150
• /
• 2015

Several reports supported that continuous exposure to 60 Hz magnetic field (MF) induces testicular germ cell apoptosis in vivo. We recently evaluated duration- and dose-dependent effects of continuous exposure to a 60 Hz MF on the testes in mice. BALB/c male mice were exposed to a 60 Hz MF at $100{\mu}T$ for 24 hours a day for 2, 4, 6, or 8 weeks, and at 2, 20 or $200{\mu}T$ for 24 hours a day for 8 weeks. To induce the apoptosis of testicular germ cell in mice, the minimum dose is $20{\mu}T$ at continuous exposure to a 60 Hz MF for 8 weeks, and the minimum duration is 6 weeks at continuous exposure of $100{\mu}T$. Continuous exposure to a 60 Hz MF might affect duration- and dose-dependent biological processes including apoptotic cell death and spermatogenesis in the male reproductive system of mice. The safety guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) indicates that the permissible maximum magnetic flux density for general public exposure is $200{\mu}T$ at 60 Hz EMF (ICNIRP Guidelines, 2010). In the present study, we aimed to examine the expression of pro- and anti-apoptotic genes regulated by the continuous exposure to 60 Hz at $200{\mu}T$ in Sprague-Dawley rats for 20 weeks. The continuous exposure to 60 Hz at $200{\mu}T$ does not affect the body and testicular weight in rats. However, exposure to 60 Hz MF significantly affects testicular germ cell apoptosis and sperm count. Further, the apoptosis-related gene was scrutinized after exposure to 60 Hz at $200{\mu}T$ for 20 weeks. We found that the message level of endonuclease G (EndoG) was greatly increased following the exposure to 60 Hz at $200{\mu}T$ compared with sham control. These data suggested that 60 Hz magnetic field induced testicular germ cell apoptosis through mitochondrial protein Endo G.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.1
• /
• pp.34-40
• /
• 2004

The purpose of this study was to measure the changes of regional cerebral blood flow (rCBF) and blood pressure (BP) in rats, following the intravenous injection of Schizandrae fructus water extract. The measurement was continually monitored by laser-doppler flowmeter and pressure tranducer in anesthetized adult Sprague-Dawley rats for 2 hours to 2 hours and a half through the data acquisition system composed of MacLab and Macintosh computer. The result of this experiment was as followed. Schizandrae fructus increased the changes of rCBF in rats significantly. The rCBF of Schizandrae fructus did not change by pretreated propranolol, atropine, L-NNA and indomethacin. But the rCBF of Schizandrae fructus was increased by pretreated methylene blue. Schizandrae fructus decreased the changes of BP, significantly. The BP of Schizandrae fructus did not change by pretreated propranolol, atropine, L-NNA and indomethacin. But the BP of Schizandrae fructus was decreased by pretreated methylene blue. There results indicated that Schizandrae fructus can increase the rCBF and decrease the BP, that is related to guanylyl cyclase activity.

• International Commerce and Information Review
• /
• v.19 no.2
• /
• pp.145-166
• /
• 2017

The FTA conventional tariffs shall be applied that the imported goods are subject to the conventional tariffs under any agreement, and the origin of the good is the contracting state in accordance with the criteria for determination origin under any agreement. An importer who intends to be eligible for the application of a conventional tariff shall file a request for the application of a conventional tariff with the head of the competent customs house before the relevant import declaration is accepted. The purpose of this study is to examine the legal standard and verification cases for the judgement of the tax tribunal of FTA conventional tariffs. Through this study, this paper is to provide several implications for companies seeking the benefits of FTA conventional tariffs. The Korean companies to do the following: confirm the effective requirements for direct transport of goods through non-parties under the Korea EU FTA, confirm the criterion for application of conventional tariffs such as certificate of origin and claims for ex post facto conventional tariffs under the Korea US FTA, confirm the issuer of origin declaration and the recognition of origin declaration of bill of lading under the Korea EU FTA, utilize the tax appeal system by denial of FTA conventional tariffs, and prepare the discrepancies in interpretation of legal standard under FTA and FTA Special Customs Act.

• Journal of Korean Academy of Nursing
• /
• v.22 no.4
• /
• pp.589-603
• /
• 1992

This study investigated a process to estimate the need for nursing staff on the basis of a patient elassification system and the required care needs and activities. The investigation was carried out in the following four steps. Step 1. Patients were classified according to the amount of nursing care need on each shift as class I (mildly ill), class II (mederately ill), class III (acutely ill), and class IV (critically ill). Step 2. Measurement of the direct nursing care hours needed for each patient class, and measurement of indirect nursing care hourse and personal time of the nursing staff. Step 3. Calculation of he total nursing workload in a nursing unit. Step 4. Estimation of the nursing staff needed. The investigation was carried out from July 17th to 30th, during 24hours every other day. The subjects were the patients and the nursing staff on two units of Seoul National University Hospital, Korea. Some of the results from the investigation are as follows : 1) Distribution of patient classification On the neuro surgical (N.S.), the distribution was class I, 22 patient, 3, class II, 27 patients, class III, 26 patients, and class IV, 25 patients, For the orthopedic surgical unit(0.5.), it was class I, 43 patients, class II, 43 patients, class III, patients, and class IV, 3 patients. 2) Direct nursing care hours per day On the N.S. unit, 3.2 hours of direct nursing care were needed for class I, 3.9 hours for class II, 5.1 hours of class III, and 6.2 hours for class IV patients, while 2.0 hours for class I, 2.5 hours for class II, 3.5 hours for class III, 5.0 hours class IV patients were needed on the 0.5. units. 3) Analysis of direct nursing care activities Activities were classified into assessment and observation(47%), medication(38.7%), communiontion(5.1%), exercise(2.4%), elimination and irrigation(1.3%), treatmemt(1.1%), hygiene(0.8%), nutrition(0.8%), and hot and cold compress(0.1%). 4) Average hours of indirect nursing care per day. On the N.S. unit 4.2 hours, and on the O.S. unit, 3.5 hours of RN indirect care was needed. 5) The average personal time used by the of nursing staff was 17 minutes for both RNs and nursing assistants in the N.S. unit, and 32 minutes for both RNs and nursing assistants in the O.S. unit. 6) Estimation of nursing staff needed on two specialized units of a university hospital For the N.S. nursing unit of 43 beds, 31 nursing staff would be indicated. For the 0.5. nursing unit of the same number of beds, 19 nursing staff would be indicated.

• Journal of Korean Academy of Nursing
• /
• v.24 no.3
• /
• pp.377-388
• /
• 1994

The purpose of this study was to determine the effects of music therapy on changes in the vital signs of patients about to undergo an operation. The patients listened to the music at a time when they were feeling preoperative anxiety up until the preanesthesia was given in the operating room. The subjects for this study were selected from sixty patients to undergo operations, who were hospitalized at Dong Eui hospital in Pusan city. They were assigned to two groups, thirty to the experimental group and thirty to the control group. The subjects were from 20 years old to 69 years old, and had no other problem except the one requiring the operation, and no premedication. The data were collected during the period from July 1 to September 30, 1993. The method used in this study was to measure state-anxiety on the ward in the morning of the operation, and vital signs immediately before leaving for the operating room. Vital signs were measured immediately before the anesthesia was given and after the experimental group had listened to the music during the ten minutes needed to prepare the operation setting. The control group just waited during ten mimutes. Vital signs were check again before the anesthesia was given. The data were analyzed by descriptive statistics, mean±SD, p-value, and t-test using the SPSS progrom. The results of this study are : 1. Systolic blood pressure taken in the operating room was elevated, over the level measured on the ward, by 5.00 ± 15.26㎜Hg in experimental group and 18.67±14.56㎜Hg in control group. (t=-3.5496, p=.0008) 2. Diastolic blood pressure was elevated by 6.67±12.95㎜Hg in experimental group and 18.67±12. 79㎜Hg in control group. (t=-3.6100, p=.0006) 3. Pulse was elevated by 2.931±9.44 / min in experimental group and 8.03±8.37 /min in control group. (t=-2.2144, p=.0307) 4. Respiration was elevated by 0.60±1.35 /min in experimental group and 1.57±1.48 /min in control group. (t=-2.6409, p=.0106) 5. Body temperature was down by 0.13±1.91'c in experimental group and elevated by 1.13±1.11'c in control group. (t=-3.1471, p=.0026) Thus, in this study there was a statistically significant difference in the change in the vital signs between the experimental group treated with music therapy and the control group which received no treatment. Because music therapy is valuable to decrease the anxiety of patients facing operations, the result of this study support its effect in relieving anxiety as a valuable nursing intervention. From this study, the following recommendations can be made : First, it is necessary to further study music therapy to develope a better system and determine optimal time. Second, it is necessary that more detailed re-search on measurement of changes in vital signs be done to determine changes over time intervals.

• The Korea Journal of Herbology
• /
• v.27 no.2
• /
• pp.85-91
• /
• 2012

Objective : Myeongganbo (MGB) composited with Hovenia Semen, Puerariae Radix and Dioscoreae Rhizoma is the prescription for protection of liver function. The purpose of this study was to investigate the effects of MGB extract against acetaminophen (APAP)-induced liver injury in mice. Methods : MGB extract was prepared by extracting with hot distilled water. The extract was freeze-dried following filtration through vacuum distillation system. Mice fasted for overnight were orally administrated with or without MGB extract of different doses (25-200 mg/kg/day). After 30 min, APAP was orally applied with a single dose (400 mg/kg). The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured in plasmas of mice. Glutathione (GSH), glutathione peroxidase GSH-px), cyclooxygenase-2 (COX-2) activity and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) level were investigated in liver homogenates. Liver sections were stained with haematoxylin & eosin, anti-TNF-${\alpha}$ and anti-mouse COX-2 antibodies. Results : APAP treatment remarkably increased AST and ALT activities in plasma but inhibited GSH and GSH-px levels in liver homogenates. Also, liver injury was significantly accelerated by APAP treatment. Furthermore, APAP remarkably elevated COX-2 activity and TNF-${\alpha}$ levels in liver homogenates. However, administration of MGB extract was able to counteract these effects. Histological studies provided supportive evidence for biochemical and molecular analysis Conclusions : These results suggest that MGB extract has potent hepatoprotective effect against APAP-induced liver injury, these properties may contribute to liver disease care.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.15 no.1
• /
• pp.17-37
• /
• 1987

The purpose of this study is to establish more rational and practical planning theory for amusement park. It analyze and consider the fluctuation of people who come and use the Tong-Ch'on amusement park. The results drawn from this reserch work are as follows; 1. The main visitors of the Tong-Ch'on amusement park are students in their twenties and thirties, and people whose incomes are below 300,000 Won a month. The purpose of visit is for a rest rather than for amusement and user prefer summer, while the user is so rare in wintertime. Those phenomena observed are somewhat different from the real purpose of a amusement park which is on purpose to make profits by offering entertainments to the users. So planner should pay attention to the three points. They are varieties, seasonable diversification and fantastic character of facilties, in the amusement park. 2. The access time of the Tong-Ch'on amusement park was 41 minutes, the use frequency was 4 times a year and resident time was 164 minutes. The relationship of the three factors are as follows; log Y(F) =1.7832-0.0277(A.T) R$^2$=0.75 Y(R. F)=31.8885+3.3217(A.T) R$^2$=0.53 Y(R. T)=224.8959-87.8309 1og(F) R$^2$=0.38 F;Use frequency(time/year) A.T;Access Time(minute) R.T;Resident Time(minute) 3. In the choice of space, there were much differences according to tole user's age, job, degree of education, companion type and purpose of use. 4. There are considerable correlation between use fluctuation and some factors. The factors are season(summer, winter) as a time, temperature, cloud amount, duration of sunshine, weather(rainy-day) as a climate and a day of the week(weekday, holiday) as a social system. The important variables are temperature, cloud amount, duration of sunshine and a day of the week(weekday, holiday) to estimate the user of amusementpark. 5. 1 can reduce the following two types of regression models. 1) log$\sub$e/ Y1 = 6.9114 + 0.l135 TEM + 0.00002 SUN -0.4068W1 + 0.4316 W3 (R$^2$= 0.94) 2) log$\sub$e/ Y2 = 7.2069 + 0.l177 TEM - 0.0990 CLO + 0.4880 W3 (R$^2$=0.95) Y; Number of User TEM; Temperature CLO; Amount of cloud SUN; Duration of Sunshine W1; Weekday W3; Holiday Those model is in order to estimate the user for management of Tong-Ch'on amusement park and use on the computation of facility sloe for reconstruction. Besides the amusement park, city park and outdoor recreation area could estimate of user through this method. But, I am not sure about the regression models because I did not apply the regression models to the other amusement park, city Park or outdoor recreation area. Therefore, I think that this problem needs to be studied on in the future.