• Journal of Preventive Medicine and Public Health
• /
• 제3권1호
• /
• pp.97-110
• /
• 1970

This survey was conducted to evaluate not only the present status of health center directors-their personal histories, their will to private practice in the future, their responses to governmental policies, -but also the distribution of doctorless myons, budget and subsidy, and director's opinions to the enhancement of health center activities. This survey questioned 116 health center directors and 16 health personnel from August to October of 1970 and obtained the following results; 1) The average ages of directors of kun, city, and total health centers were $43.2{\pm}7.8,\;42.1{\pm}7.7,\;and\;42.9{\pm}10.3$ respectively. 2) The average family sizes of directors of kun, city, and total health centers were $5.6{\pm}2.7,\;5.6{\pm}2.1,\;and\;5.6{\pm}2.6$ respectively. 3) Directors holding M. D. degrees were 79.3%, those holding qualified M. D. degrees ('approved director') were 20.7%. 4) M. P. H., M. S., and Ph. D. holders were 6.0%, 6.1%, and 4.3% respectively. 5) The average duration of present directorship in kun and city were 30.2 months and 20.4 months respectively. 6) The majority of directors had been employed in related fields before assuming current position : directorship at other health center 26.7%, army 22.4%, health subcenter 21.6%, private practice 19.0%. 7) Average length of directorship is 41.8 months. Average length of public health career, including health subcenter and present position, is 56.5 months. 8) Both rural and urban experience in health centers for regular directors is 16.3% and for approved directors, 12,5%. A total of 15.5% of all survey directors had experience in both rural and urban health center. 9) A total of 70.7% of health center directorships were staffed by local doctors. 10) Nearly 40% wanted to quit the directorships within 3 years and 60.3% had already experienced private practice. 11) Of the regular directors 17.4% felt strongly about devoting their lives to public health fields, but only 4.1% of the approved approved directors felt so. 12) There wire 432 doctorless myons among 996 respondent myons and 4.5 doctorless myons per kun. 13) The percentage of doctorless myon by Province are as follows, Cholla buk-do 57.2%, Cholla nam-de 55.0%, Kyungsang nam-do 52.0%, Kyungsang buk-do 49.7%, Chungchong but-do 42.4%, Kyonggi-do 32.9%. Cheju-do 30.8%, Kangwon-do 25.8%. 14) Two thirds of health critters have experienced the abscence of the director for a certain period since 1966 and the average span of the abscence was 18.2 months. 15) The percentage of doctorless myons increased proportionally with the span of the director's abscence. 16) The average budgets of health centers, kun, city and ku, were $W15.03\;million{\pm}W4.5\;million,\;W22.03\;million{\pm}W17.80\;million,\;W13.10\;million{\pm}W7.9\;million$ respectively. 17) Chunju city had the highest health budget per capita(W344) while Pusan Seo ku had the lowest(W19). 18) Director's medical subsidies are W30,000-50,000 in kun, and roughly W20,000 in city. 19) The older of priority in health center activities is T.B. control(31.1%), Family Planning and M. C. H.(28.0%), prevention of acute communicable disease and endemic disease (18.2%) and clinical care of patients(14.3%). 20) Nearly 32% opposed in principle the governmental policy of prohibiting medical doctors from going abroad. 21) Suggestions for immediate enhancing the position of director of health centers and subcenters: (1) Raise the base subsidy (48.2%), (2) Provide more opportunities for promotion (20.7%), (3) Exemption from army services(12.1%), (4) Full scholarship to medical students for this purpose only (7.8%). 22) A newly established medical school was opposed by 56.9% of the directors, however 33.6% of them approved. 23) Pertaining to the division of labor in Medicine and Pharmacy, the largest portion (31.9%) urged the immediate partial division of antibiotics and some addictive drugs to be given only by prescription. 24) More than half wanted a W70,000 level for the director's medical subsidies, white 36.2% stated W50,000. 25) Urgently needed skills in the kun are clinical pathologist (38.6%) and doctor (health center director) (25.5%); while in the city nurse (37.1%), doctors(clinical)(31.4%) and health educators(14.4%) are needed. 26) Essential treatment for the better health center administration; raising the base subsidy (22.7%), obtaining the power of personal management (19.3%) and the establishment of a Board of Health (14.3%). etc.

• Journal of Korean Society of Forest Science
• /
• 제83권1호
• /
• pp.20-24
• /
• 1994

In woody species with a long life span, the studies on inheritance of any trait may be very time consuming and laborious. Chloroplast DNA(cpDNA) has been a valuable tool in such studies since it has several unique features such as limited genome size and cytoplasmic inheritance. In the present study, cpDNAs from five different species of Populus(P. alba, P. glandulosa, P. alba${\times}$P. glandulosa, P. davidiana, and P. nigra), and Nicotiana tabacum were compared with regard to restriction fragment length polymophism. The results showed that cpDNAs among the species were very conserved, although some polymorphisms were observed when the DNAs were digested with restriction enzyme EcoRI or KphI. The other enzymes (Bgl II, and PstI) tested produced identical restriction fragmentation pattern among the species. However, cpDNAs from all the five Populus species showed different restriction fragmentation pattern from that of tobacco with the four restriction enzymes tested. Southern hybridization with tobacco rbcL gene fragment as a probe also produced identical pattern among Populus species. The results indicate that cpDNAs in the genus are very well conserved during evolution.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• 제38권11호
• /
• pp.1309-1315
• /
• 2014

The switch for a maglev vehicle should be designed such that the vehicle safely changes its track without touching the guiderail. In particular, a medium-to-low-speed EMS -type maglev train relies heavily on a U-type electromagnet where it generates levitation force and guidance force simultaneously. Therefore, it is necessary to evaluate the safety of the vehicle whenever it passes the switch, as it lacks active control of the guidance force. Furthermore, when the vehicle passes a segmented switch, which is a group of curves made up of connected lines with a small radius of curvature, it may come into mechanical contact with the guiderail owing to the excessive lateral displacement of the electromagnet. The goal of this study is to analyze the influence of a segmented switch on the safety of major design-related variables for achieving improved running safety. We propose a three-dimensional multibody dynamics model composed of two cars with one body. Using the proposed model, we perform a simulation of the lateral air gap, which is one of the measurements of the running safety of the vehicle when it passes the switch. The analyzed design variables are the length between short span girder, the articulation angle, the length between two centers of a fixed girder at its ends, and the number of girders. On the basis of the effects of the considered design variables, we establish an optimized design of a switch with improved safety.

• Journal of the Korea Concrete Institute
• /
• 제20권3호
• /
• pp.393-404
• /
• 2008

The approaches in many design codes for the estimation of the deflection of flexural reinforced concrete (RC) members utilize the concept of the effective moment of inertia which considers the reduction of flexural rigidity of RC beams after cracking. However, the effective moment of inertia in design codes are primarily based on the ratio of maximum moment and cracking moment of beam subjected to loading without proper consideration on many other possible influencing factors such as span length, member end condition, sectional size, loading geometry, materials, sectional properties, amount of cracks and its distribution, and etc. In this study, therefore, an experimental investigation was conducted to provide fundamental test data on the effective moment of inertia of RC beams for the evaluation of flexural deflection, and to develop a modified method on the estimation of the effective moment of inertia based on test results. 14 specimens were fabricated with the primary test parameters of concrete strength, cover thickness, reinforcement ratio, and bar diameters, and the effective moments of inertia obtained from the test results were compared with those by design codes, existing equations, and the modified equation proposed in this study. The proposed method considered the effect of the length of cracking region, reinforcement ratio, and the effective concrete area per bar on the effective moment of inertia, which estimated the effective moment of inertia more close to the test results compared to other approaches.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• 제39권2호
• /
• pp.120-127
• /
• 2003

In Korea, Trachysalambria curvirostris occurs widely along the south and west coasts with a range extending from Kanghwado in the northwest down to Sarangdo in the southeast. Sex ratio showed seasonal variations, with a mean value of 48.6% for the females. T. curvirostris produces one cohort a year, with the ovaries ripening from July to August. Insemination appeared to take place from June to August, as more than half of the females sampled in the study of over 19 mm carapace length were inseminated. The mean gonado somatic index (GSI) reached a maximum between July and August. The smallest mature female found was a 18 mm carapace length (CL). Size at 50% sexual maturity (CL$_(50)$), determined from both mature females and inseminated females was 18.89 mm and 19.91 mm CL, respectively. The life span of females appeared to be 14-15 months according to size frequency distributions, while that of the male was 13-14 months. Population growth was estimated by the modified von Bertalanffy growth function incorporating seasonal variation in growth. Based on the growth parameters (K = 1.40 yr$_(-1)$ and L$L\infty$ = 29.54 mm CL for females, and K = 2.00yr$_(-1)$ and L$L\infty$ = 18.95 mm CL for males) growth curves showed that females grew faster and reached a larger size than males.

• Steel and Composite Structures
• /
• 제34권1호
• /
• pp.1-15
• /
• 2020

This paper presents experimental and numerical studies on effects of local damages on the in-plane elastic-plastic buckling and strength of a fixed parabolic steel tubular arch under a vertical load distributed uniformly over its span, which have not been reported in the literature hitherto. The in-plane structural behaviour and strength of ten specimens with different local damages are investigated experimentally. A finite element (FE) model for damaged steel tubular arches is established and is validated by the test results. The FE model is then used to conduct parametric studies on effects of the damage location, depth and length on the strength of steel arches. The experimental results and FE parametric studies show that effects of damages at the arch end on the strength of the arch are more significant than those of damages at other locations of the arch, and that effects of the damage depth on the strength of arches are most significant among those of the damage length. It is also found that the failure modes of a damaged steel tubular arch are much related to its initial geometric imperfections. The experimental results and extensive FE results show that when the effective cross-section considering local damages is used in calculating the modified slenderness of arches, the column bucking curve b in GB50017 or Eurocode3 can be used for assessing the remaining in-plane strength of locally damaged parabolic steel tubular arches under uniform compression. Furthermore, a useful interaction equation for assessing the remaining in-plane strength of damaged steel tubular arches that are subjected to the combined bending and axial compression is also proposed based on the validated FE models. It is shown that the proposed interaction equation can provide lower bound assessments for the remaining strength of damaged arches under in-plane general loading.

• Journal of Bio-Environment Control
• /
• 제13권4호
• /
• pp.217-225
• /
• 2004

This study was performed to provide the basic knowledge about the mushroom cultivation facilities. Classified current status of cultivation facilities in Gyeongnam province was investigated by questionnaire. The structure of Pleurotus eryngii cultivation facilities can be classified into the simple and permanent frame type. The simple frame structures were mostly single-span type, on the other hand, the permanent frame structures were more multi-span than simple structures. And the scale of cultivation facilities was very different regardless of structural type. But as a whole, the length, width and ridge height were prevailing approximately 20.0 m, $6.6\~7.0m$ and $4.6\~5.0m$ range, respectively. The floor area was about $132\~160\;m^2$, and floor was built with concrete to protect mushrooms from various harmful infection. The roof slope of the simple and permanent type showed about $41.5^{\circ}\;and\;18.6\~28.6^{\circ}$, respectively. The width and layer number of growing bed for mushroom cultivation were around $1.2\~1.6m$, 4 layers in common, respectively. Most of year round cultivation facilities were equipped with cooler, heater, humidifier, and ventilating fan. Hot water boiler was the most commonly used heating system, the next was electric heater and then steam boiler. The industrial air conditioner has been widely used for cooling. And humidity was controlled mostly by ultra-wave or centrifuging humidifier. But some farmers has been using nozzle system for auxiliary purpose. More then $90\%$ of the mushroom house had the independent environment control system. The inside temperature was usually controlled by sensor, but humidity and $CO_2$ concentration was controlled by timer for each growing stage. The capacity of medium bottle was generally 850 cc and 1100cc, some farms used 800 cc, 950 co and 1,250 cc. Most of mushroom producted has been usually shipped to both circulating company and joint market.

• Journal of Bio-Environment Control
• /
• 제26권4호
• /
• pp.283-290
• /
• 2017

In this study, the method to attach plastic film on the side vent from inside of greenhouse for the entire length was developed as the way to make crops less stressful while uniformly getting outside air into the greenhouse when ventilating using roof ventilation fans at single-span plastic greenhouse for oriental melon in a low-temperature period. The plastic film was installed from ground to 10cm below from the height where side vent is fully opened. In order to verify that the improved side vent can improve greenhouse environment and fruit yield, it was compared with the control plot of conventional side vent. Both greenhouses were not ventilated until February 25th, 2017. Air temperature in both greenhouses exceeded $40^{\circ}C$ in mid February. Therefore, it is judged that the greenhouse should be ventilated from mid February. Air temperature in the control plot exceeded $30^{\circ}C$ from late April. Therefore, it is judged that the plastic film attached to the inside of side vent should be removed in late April, or in early May at the latest. Soil temperature in the treatment plot in the mid Aril exceeded $20^{\circ}C$, which is suitable for growth, while that in the control plot was still below $20^{\circ}C$. Soil temperature in the control plot finally exceeded $20^{\circ}C$ in late April. The consumption of electricity was 47.2 kWh in the treatment plot, and 48.3 kWh in the control plot, which was no significant difference. The marketable yield of oriental melon in the treatment plot was 5,094kg, which was 23.9% more than that in the control plot, 4,113kg. The marketable fruit ratio was 73.5% in the treatment plot, and that in the control plot was 73.9%, which was no significant difference.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• 제30권5A호
• /
• pp.407-415
• /
• 2010

In Korea, more than 90% of the total number of steel bridges built for 40~70 m span length is a steel box-girder bridge type. A steel box-girder bridge is suitable for long span or curved bridges with outstanding flexural and torsional rigidity as well as good constructability and safety. However, a steel box-girder bridge is uneconomical, requiring many secondary members and workmanship such as stiffeners and ribs requiring welding attachments to flanges or webs. Therefore, in US and Japan, a plate girder bridge, which is relatively cheap and easy to construct is generally used. One type of the plate girder bridge is the two- or three-main girder plate bridge, which is a composite plate girder bridge that minimizes the number of required main girders by increasing the distance between the adjacent girders. Also, for the simplification of girder section, the stiffener which requires attachment to the web is not required. The two-main steel girder plate bridge is a representative type of plate girder bridges, which is suitable for bridges with 10 m effective width and has been developed in the early 1960s in France. To ensure greater safety of two- or three-main girder plate bridges, a larger steel section is used in the bridge domestically than in Europe or Japan. Also, the total number of two- or three-main girder plate bridge constructed in Korea is significantly less than the steel box girder bridge due to a lack of designers' familiarity with more complex design detailing of the bridge compare to that of a steel box girder bridge design. In this study, a new construction method called Turn Over method is proposed to minimize the steel section size used in a two- or three-main girder plate bridge by applying prestressing force to the member using confining concrete section's weight to reduce construction cost. Also, a full scale 20 m Turn Over girder specimen and a Turn Over girder bridge specimen were tested to evaluate constructability and structural safety of the members constructed using Turn Over process.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• 제14권4호
• /
• pp.907-913
• /
• 1994

The design of railroad bridges differs from road bridges because of the interface between track structure and bridge structure. The track generally consists of Continuous Welded Rail(CWR) which is fixed by fasteners to the sleepers embedded in the ballast. The ballast provides the interface between the track structure and the bridge structure. Large longitudinal forces can develop from the temperature variation in rail and bridge structure. These longitudinal forces are specially important for long bridges because the bridge layout for span length, pier dimensions and arrangement and type of bearings can be governed by these forces. This report provides a comparison of longitudinal track forces determined by analysis and actual measured track forces. In recent practice the longitudinal track force for European railways is analyzed using a finite element analysis method. This method is very time-consuming and requires the detail design of the bridge to be complete. Redesign is required if the design criteria for longitudinal track forces are not satisfied. There is a need to develop a simple analysis method considering the large number of bridge structures and a relatively short design time on the Korean High Speed Rail Project. The analysis results presented herein, based on a simplified analysis, show good agreement with those obtained by finite element analysis, as well as with those measured on an actual track. The proposed analysis method is particularly useful for the preliminary design of bridge structures.