• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.4
• /
• pp.52-60
• /
• 2015

Operation area of corps was expanded under military reformation, and extending range of 155 mm howitzer became important issue. New approach is needed to extend range to 80 kim. Ramjet engine is air breathing engine, and it can provide specific impulse several times more than solid rocket motor so that range is extended using same weight of propellant. If the ramjet engine is gun-launched system, it does not require any other booster because muzzle velocity is near Mach 3. Especially solid fuel ramjet (SFRJ) does not have any moving part so that it is favorable for gun-launching system which is under high stress during launching. In this paper, we design air intake, combustion chamber, and nozzle of 155 mm gun launched ramjet propelled artillery shell with inviscid flow assumption. We conduct parameter study to have range more than 80 km, and maximum high explosive volume.

• Korean Journal of Veterinary Service
• /
• v.31 no.3
• /
• pp.347-356
• /
• 2008

The purpose of this study was to evaluate the efficacy and cross-protection of serovar 12 against serovar 4 or 5 of H parasuis with M+$Parapac^{(R)}$. A total of 141 piglets from 2(A and B) farms were used and divided into experimental group and control group in each farm. Farm A has been detected H parasuis serovar 12, whereas farm B has been detected H parasuis serovar 4 or 5 from post-weaned pigs with PMWS. The piglets were vaccinated intramuscularly with 2.0ml of M+$Parapac^{(R)}$ in experimental group or normal saline in control group at 1 week of age. A same booster dose was given at 3 weeks of age. In order to value the antibody titer to H parasuis using by tube agglutination test, blood samples were collected from piglets at the aged of 1 week, 6 and 14 weeks. In experimental group and control group, the average antibody titers were $32.5{\pm}21.0,\;114.5{\pm}34.0,\;98.1{\pm}55.4$ and $32.9{\pm}18.6,\;25.8{\pm}36.9,\; 746.7{\pm}1,215.8$ at the aged of 1 week, 6 and 14 weeks, respectively. The cumulative clinical sign indexes by standard guideline of Schering-Plough Animal Health Corp were 486 and 1,069, respectively. The average daily gains and feed conversion rates were $0.553{\pm}0.016kg$ and $0.492{\pm}0.004kg$, and 1.99 and 2.24, respectively. The average gross lesion scores were $1.0{\pm}0.8$ and $1.9{\pm}0.6$, respectively. According to these results, the M+$Parapac^{(R)}$ containing H parasuis serovar 12 may be induce circulating antibodies that cross-react with serovar 4 or 5 and have a protection of PMWS with H parasuis.

• Journal of Acupuncture Research
• /
• v.25 no.1
• /
• pp.25-55
• /
• 2008

Objectives : The aim of the present study was to observe the effect of Astragali Radix Herbal-Acupuncture Solution(AR-HAS) at $ST_{36}$(jok-samni, $Z\acute{u}s\bar{a}n$ Li) on collagen- II -induced arthritis(CIA) in mice. Methods : DBA/1J mice were immunized with bovine type II collagen(CII) on days 0 and 21 to induce arthritis. The mice were divided into 5 groups : normal group(no CIA), control group(CIA+no treatment), needle prick group(CIA+single prick with an injection needle), saline group(CIA+saline injection) and ARHA group(CIA+ R-HA treatment). The needle prick, saline injection, and AR-HA groups were injected on the right $ST_{36}$(jok-samni) of mice for 9 weeks, 3 times a week, beginning 4 weeks after the booster immunization. Results : 1. The incidence of arthritis, AI(arthritis index), and joint edema decreased in the AR-HA group. 2. Weight gain, hypertrophy of the spleen, adhesion of the tissues, and transformation of the joint were restrained in the AR-HA group. 3. The concentrations of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, $IFN-{\gamma}$ in CIA mouse serum and $IFN-{\gamma}$, IL-10 in the CIA mouse spleen cell culture decreased significantly at $ST_{36}$ in the AR-HA group. 4. Total cell counts increased significantly, and the ratio of $CD3e^+$ to $CD45R^+$, $CD4^+$ to $CD8^+$, and $CD4^+$ to $CD25^+$ cells decreased significantly at $ST_{36}$ in the CIA mouse spleen cell culture of the AR-HA group. 5. Total cell counts decreased significantly, and $CD4^+/CD25^+$ and $CD45R^+/CD69^+$ decreased significantly at $ST_{36}$ in the CIA mouse lymph nodes of the AR-HA group. 6. $CD3e^+/CD69^+$ and $CD11b^+/Gr-1^+$ cells decreased significantly at $ST_{36}$ in the CIA mouse joints of the AR-HA group. 7. The histological examination showed that cartilage destruction and synoviocyte proliferation decreased in the CIA mouse joints of the AR-HA group, and collagen fiber was expressed similar to that seen in the normal group. Conclusions : Our experiments show that at $ST_{36}$, an anti-inflammatory mechanism of AR-HA controls synovial cell proliferation and protects against cartilage destruction in rheumatoid arthritis.

• Aerospace Engineering and Technology
• /
• v.2 no.1
• /
• pp.171-181
• /
• 2003

The nose fairings of KSR-III are designed to be separated from the rocket by explosive force at the mission altitude to expose the payload. Adequate amount of separation force should be imposed to allow safe separation without collision between the fairings and the rocket, and the separation device was designed for the separation at very high altitude where almost no air load was expected. As the development of KSR-III goes on, several design changes have made and lower separation altitude of 45km is expected as a result. Under these circumstances, it is required to determine if the nose fairings can be separated without collision with much severer air load than for the design condition. In this study, the 6-DOF motion analysis program, PASEM, which was developed to predict the strap-on booster separation, is modified to simulate the pivotal motion of the fairings at early stages of separation. The accuracy of pivot motion simulation is validated by comparison with the results of ground test and the accurate separation conditions are deduced from it. Trajectory simulations are performed to see if separation without collision is possible with varying angle of attack, direction of gravity, and the effect of gust. It is also found that reducing the separation angle of the clamshell hinge from 60 degrees to 40 degrees can enhance separation safety and separation at lower altitude of 40km can be done without collision.

• Clinical and Experimental Pediatrics
• /
• v.53 no.1
• /
• pp.67-71
• /
• 2010

Purpose : Recently, we have noticed an increase in the number of patients with mumps in Incheon, Korea. The aim of this study is to estimate the regional trend in mumps incidence and to evaluate the factors related to the recent increase. Methods : We reviewed the medical records of 66 patients with mumps who had been admitted to Incheon St. Mary's Hospital from July 1999 to June 2009. We compared the differences in records between "outbreak, 2009" and "nonoutbreak, 2000-2008." Results : Of the 66 patients, 35 (53%) were admitted in 2009, and 31 (47%) were admitted between 2000 and 2008. Most of the patients admitted during the outbreak were over 15 years of age (80.0%), were born before 1993 (77.1%), and had received a single dose of mumps vaccine (62.9%). There were no significant differences in contact history, present address, clinical manifestations, and complications, except for orchitis, between the two groups. Conclusion : There was a sharp increase in the number of inpatients with mumps who were born before 1993 and who were over 15 years of age. We recommend that a booster vaccination be considered for adolescents and young adults born before 1993 who are susceptible to mumps infection due to their reduced opportunities for receiving two doses of mumps vaccine.

• Journal of Preventive Medicine and Public Health
• /
• v.7 no.2
• /
• pp.403-415
• /
• 1974

The author has investigated epidemiological features of human cases of epidemic encephalitis (E. E.) in the Republic of Korea and the status of antibody requisition in pre-and post-epidemic time. And virological and serological studies with regarding the relationship of E. E. infection between human and piglet, and field survey against its vector by means of virus isolation from mosquitoes were carried out. Finally, vaccine field trial against human population has also been evaluated in order to confirm its effectiveness. The results of the studies are summarized as follows : 1. The annual incidence of reported cases during the past 25 years (1949-1973) in the Republic of Korea has shown two patterns, one was typical cyclic incidence and the other one was irregular. Annual average morbidity and mortality rate per 100,000 population were 5.7 and 2.1 and fatality rate was 34.6% in typical cyclic years. 2. With regard to the geographical distribution of E. E., the province of Jeolla-Bug-Do illustrated the highest incidence regardless of the epidemic size. 3. The main epidemic period was between mid-August and mid-September (above 90% of the total number of cases). The first case was reported in middle of July and the epidemic ceased in late of October. 4. An analysis of the age distribution of cases of E. E., has shown that above 90% of the total cases occurred in the age groups under 14 years and it was noted that about its 54% were occurred in the age groups between 5-9 years group. 5. Through the Haemagglutination Inhibition (H-I) test for the laboratory diagnosis of E. E., it was found that higher H-I antibody titer was usually detected in the convalescent phase, 15 days after onset. 6. The H-I antibody survey against 563 healthy population by age groups during the pre-epidemic season showed that 422(75%) were less than H-I titer, 1:20 and 122(21.7%) were positive H-I titer, 1:20. Among the 94 American in Seoul who had not been in E. E. endemic area previously only one person had appeared sero-conversion as a H-I titer of 1:80 after post-epidemic season. 7. The E. E. virus could be isolated from the mosquitos pools-C, tritaeniorhyncus which were caught between late July and middle August. 8. E.E. Virus was also isolated from piglet blood on early August and H-I antibody conversion was occurred mostly on middle of August. 9. H-I antibody sero-conversion rate reached to high level when vaccine purified by mouse brain tissue inoculated, showing 98.9%. Higher antibody titer was acquired when booster inoculation was performed, Four fold rise of H-I add N-T antibodies was confirmed with 93.2% and 82.1% respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.5
• /
• pp.419-426
• /
• 2018

For an orbit transfer in a space exploration mission, a solid or liquid rocket booster is included at the last stage of the launch vehicle. During the orbit transfer, thrust misalignment can cause a severe orbit error. Three axis attitude control or spin stabilization can be implemented to minimize the error. Spin stabilization technique has advantages in structural simplicity and lightness. One of ways to apply the spin stabilization to the payload is to include a spin table system in the launch vehicle. In this paper, effect of the spin table system on separation dynamics of the payload is analyzed. Simple model of the spin table to mimic basic functions is designed and simulation environment is established with the model. Effect of the spin table is tested by evaluating separation dynamics of a payload with and without the spin table. Analysis on tolerance effect of separation spring constant on separation dynamics of a payload is conducted.

• Korean Journal of Poultry Science
• /
• v.28 no.1
• /
• pp.49-54
• /
• 2001

Two experiments were conducted to investigate the influence of dietary supplemental Enviro on noxious gas of environmental controlled poultry house and performance of broiler chicks. Diets contained 21.5, 19.00 CP and 3,100, 3,200 kcal/kg ME, respectively for starting and finishing period. Enviro were supplemented with 0, 0.2, 0.4, 0.6 and 0, 0.1, 0.2, 0.3% in Expt. 1 and 2, respectively. $CO_{2}$ and ammonia gas were periodically detected for finsihing period in Expt. 1. Weight gain, feed intake and feed conversion(FC) were measured for five weeks in Expt. 2. ND antibody titer were also measured after primary and booster vaccination at two and three weeks old. Blood cholesterol and nutrients digestibility were In Expt. 1, ammonia and $CO_{2}$ gas of chicks fed 0.2% Enviro showed 32.8ppm and 1,719ppm in poultry house and significantly decrease compared to that of control(P〈0.05). $CO_{2}$ gas was 1,814ppm in 0.4% Enviro treatments and also significantly lower than control(P〈0.05), but tended to be increased compared to that of 0.2% Enviro treatments, In Expt. 2, weight gain of chicks fed 0.1 and 0.2% Enviro was significantly increased for starting period(P〈0.05), but was not statistically different for finishing period. Feed intake was no significantly different of all treatments. Chicks showed lower FC in 0.3% Enviro treatment for starting period(P〈0.05) than others, but was not for finishing period. ND AB titer of chicks fed Enviro was prone to be higher than control, but was not significantly different. Total blood cholesterol was not significantly different of all treatments, but tended to be high in 0.1 and 0.2% Enviro treatments. HDL of chicks fed those levels showed significantly higher than control(P〈0.05), whereas LDL was tended to be decreased in those treatments. The digestibilites of crude protein and fiber were improved in 0.1 and 0.2% Enviro treatments relative to those of control, but was not statistically different. However, crude ash digestibility was significantly improved in 0.1 and 0.2% Enviro treatments(P〈0.05). Chicks also showed AMEn in 0.1, 0.2% Enviro treatments, but was no significance. The results of these experiments indicated that 0.1% Enviro supplement would be maximize the performance of broiler chicks.

• Pediatric Infection and Vaccine
• /
• v.19 no.2
• /
• pp.55-60
• /
• 2012

Purpose: We conducted the immunoassay of pertussis according to ages, in order to evaluate protective immunity against pertussis in Korean populations. Methods: Healthy subjects were enrolled at four university hospitals in Korea. The subjects were grouped as seven age groups (every 10 years). Antibodies against pertussis toxin (PT) in sera were measured by enzyme linked immunosorbent assay (ELISA) kits. Geometric mean concentrations (GMC) of antibodies and the ratios of the subjects with seroprotective antibody levels were determined. The subjects with antibody titers ${\geq}24.0EU/mL$ were considered to seroprotective as the manufacturer's protocol. Results: Total 1,605 subjects (age: 2 months-65 years) participated in this study, and their GMC was $56.16{\pm}50.54EU/mL$. Among seven age groups, age group <11 year showed the highest GMC ($64.78{\pm}53.24EU/mL$) (P<0.001). In the analysis of the ratios of the subjects with seroprotective antibody titers, 68.2% of the subjects were proven to seroprotective, and age group <11 year also showed the highest ratio (76.5%) (P<0.001). Conclusions: We found that adolescences or adults (age group ${\geq}11$ year) showed lower levels of antibody against pertussis and lower ratio of the subjects with seroprotective antibody titers than children (age group <11 year).

• Radiation Oncology Journal
• /
• v.11 no.2
• /
• pp.363-367
• /
• 1993

A retrospective analysis was peformed on 42 patients with carcinoma of the uterine cervix who were treated with external beam (EB) radiation therapy alone at the Department of Therapeutic Radiology, Seoul National University Hospital from March 1979 to December 1988. After whole pelvic field irradiation of 50Gy, all the patients received additional booster dose of 12-22Gy to the primary tumor Thirty one received EB radiotherapy alone because of poor geometry for intracavitary application,5 because of medical problems and 6 because of other reasons. Five year locoregional control rate and five year survival rate were $34.5\%\;and\;35.4\%,$ respectively. Five year survivals were $66.7\%,\;36.4%,\;32.8\%\;and\;25.0\%$ for stage IIA, IIB, IIIB and IVA, respectively. The response one month after treatment well correlated with prognosis. The incidence of grade 2 and 3 complication was $12\%\;and\;10\%,$ respectively. There was tendency of increased complication with advanced stage.