• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.84-90
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• 2018

Cultivation of high-quality forage crop by using fallow field during winter is required for national high feed self-sufficiency and establishment of self-supply system of high-quality forage crop. Field experiments for cultivation of high-quality winter forage crop were conducted at the paddy and upland fields in Cheonan and Anseong city with treatments of single Italian ryegrass(IRG) and IRG mixed with forage barley at the paddy field and of single forage barley and forage barley mixed with IRG at the upland field in the Mid-west plain. Several cultivation conditions such as broadcasting IRG seed under standing rice, sowing time, tillage method, drainage condition, mixed sowing with forage barley were compared to know the change of growth, yield and quality of winter forage crop. In particular, over-wintering rate and dry matter yield were decreased significantly in late-sown IRG and moisture-stressed forage barley. Yield and quality of forage crops were increased by sowing after tillage, mixed sowing of IRG with barley at the paddy field with good drainage. High yield as much as dry matter $10MT\;ha^{-1}$ with high feed value could be obtained by early sowing of feed barley mixed with IRG at the upland field. Cultivation conditions such as early sowing, sowing after tillage, drainage management are required for higher dry matter yield, quality and stable cultivation of winter forage crops in the mid-west plain of Korea.

• Journal of the Korean Society of School Health
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• v.4 no.2
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• pp.176-192
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• 1991

School nurses, in service of 102 special schools in Korea, were urveyed by mail questionnaires from February to March, 1991 and 77 of hem responded. Collected data were analyzed to establish the direction of health management in special school and to provide basic reference data for improving the quality of the management of school-nurses' services. The major findings are as follows: Out of special schools surveyed, 67.5% is private school and 83.2% is located in city. The average number of classes, students, and educational personnels per special school is 17.2, 194, and 28 respectively. The average age of school-nurses surveyed is 32.7. The proportion of graduates from the junior college and upward was 97.4%, the proportion of the married was 71.4%. Out of respondents, 71.4% has religion : 79.2% has past career in the fields of clinics or public health: 62.3% accompanishes independent services: 77.9% belongs to primary school. About 69% of nursing room in special schools surveyed is located at the first floor. Out of special school surveyed, 90.9% has no organization for school health programms: Only 18.2% entrusted everyone of school doctor, school dentist, and school pharmacists with school health. 46.8% of respondents didn't know about the annual budget for school health programmes. The average annual expenditure for school health programme per special school was 317,000F26. won and the purchase cost for medical supplies accounted for the larger part of them. The monthly average number of students utilizing school nursing room was 71 per school, annual utilization times of school nursing room was 4.4 per student and utilization due to injury was prevalent by 26.6% and there is some differences in using the school nursing room according to disabled area. Rate of referral to medical facilities was 1.4%. The leading reason of referral to medical facilities was high fever among those who have visual handicaps, fracture among those who have emotional disturbance, injury by trauma among others. Nine hundred fifty six students of students in special school surveyed have sufferd from epilepsy and prevalence rate of epilepsy was 6.4%. Only 22.6% of respondents replied that they had physical examination more than 2 times per year. Out of respnodents, 98.7% answered that they had health education and 67.1% of them ansered that they educated in a classroom, 98.7% of respondents emphasized need of sex education. Respondents put the most emphasis on the personal hygiene when they performed health education and they used broadcasting education in the area of visual handicaps, OHP or VTR in hearing handicaps, home correspondence or OHP VTR in other area importantly. About 47% of repondents answered that health education was the most difficult and they emphasized that definite guide on health management was requested. Respondents had self-confidence and high perfomance rate in most of school-nurses' services completely, but so they was not in area of evaluation of school health programmes, an examination of physical strength, evaluation of health education, management of school purification area, suture of wounds. In consideration of above findings, we may conclude that special education for school-nurse in special schools as well as improvement of definite guiding principles are requested to establish direction for health management in special schools and to improve the degree of quality for school-nurses' sevices in special schools.

• Spatial Information Research
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• v.18 no.5
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• pp.1-11
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• 2010

Since January 2009, Seoul Metro Government(SMG) is operating own Network RTK Systems connecting four(4) GNSS Reference Stations which are installed inside Seoul Metro City area. SMG is currently providing VRS data service via wireless internet for Network-RTK and RINEX data observed from GNSS Reference Stations. This paper will discuss utilization of data available from SMG Network-RTK System for various applications, and present the test results on practicalities of Virtual RINEX data. For the utilization of data available from SMG Network- RTK system, 1)NTRIP data delivery of GNSS realtime observables streaming and converting to RINEX at receiving side, 2) monitoring deformation of bulky structures using GNSS observation were discussed. In addition to those discussion, 3) broadcasting VRS correction data for job site via radio modem after acquiring such correction data on-line using NTRIP based GNSS Internet Radio from SMG Network-RTK System were introduced. For the test results on practicalities of Virtual RINEX data, 1) the post-processing results of the GNSS observation data on a certain point with GNSS Reference Station data have been compared to the post-processing results of Virtual RINEX data on the same point generated from SMG Network-RTK System, and 2) VRS RTK positioning results for a certain point and post-processing results of Virtual RINEX data for the point were compared. The results showed only a few mm difference, and the high possibility for using Virtual RINEX data for post-processing applications.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.4
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• pp.181-191
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• 2016

A Satellite Based Augmentation System (SBAS) provides differential correction and integrity information through geostationary satellite to users in order to reduce Global Navigation Satellite System (GNSS)-related errors such as ionospheric delay and tropospheric delay, and satellite orbit and clock errors and calculate a protection level of the calculated location. A SBAS is a system, which has been set as an international standard by the International Civilian Aviation Organization (ICAO) to be utilized for safe operation of aircrafts. Currently, the Wide Area Augmentation System (WAAS) in the USA, the European Geostationary Navigation Overlay Service (EGNOS) in Europe, MTSAT Satellite Augmentation System (MSAS) in Japan, and GPS-Aided Geo Augmented Navigation (GAGAN) are operated. The System for Differential Correction and Monitoring (SDCM) in Russia is now under construction and testing. All SBASs that are currently under operation including the WAAS in the USA provide correction and integrity information about the Global Positioning System (GPS) whereas the SDCM in Russia that started SBAS-related test services in Russia in recent years provides correction and integrity information about not only the GPS but also the GLONASS. Currently, LUCH-5A(PRN 140), LUCH-5B(PRN 125), and LUCH-5V(PRN 141) are assigned and used as geostationary satellites for the SDCM. Among them, PRN 140 satellite is now broadcasting SBAS test messages for SDCM test services. In particular, since messages broadcast by PRN 140 satellite are received in Korea as well, performance analysis on GPS/GLONASS Multi-Constellation SBAS using the SDCM can be possible. The present paper generated correction and integrity information about GPS and GLONASS using SDCM messages broadcast by the PRN 140 satellite, and performed analysis on GPS/GLONASS Multi-Constellation SBAS performance and APV-I availability by applying GPS and GLONASS observation data received from multiple reference stations, which were operated in the National Geographic Information Institute (NGII) for performance analysis on GPS/GLONASS Multi-Constellation SBAS according to user locations inside South Korea utilizing the above-calculated information.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.521-525
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• 2014

This study was conducted in the central northern area that has a smaller production of winter forage crop compared to the southern areas, in order to identify the optimal mix of seeding, mix ratio and seeding method. The results showed that among the mixed seeding of triticale and crimson clover, the mix of triticale+crimson clover, mixing ratio is 8:2 (w/w), had the largest dry weight of 1,462 kg/10a, which was more than either single seeding of triticale or crimson clover. Although there were no total quantity differences between different mix ratios, there were differences in quantity between sowing types with broadcasting seeding is more than in narrow strips seeding. In forage value of mixed seeding combination, crude protein contents in single seeding of crimson clover showed the highest value at 17.2%, and in single seed of triticale showed the lowest at 7.4%. In mixed seeding combination the crude protein contents were highest in triticale+crimson clover, mixing ratio is 7:3 (w/w), at 9.0%. The mixed seeding between triticlale and legume crops will helpful for increasing forage value.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1193-1203
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• 2008

An active antenna(AA) can have wider bandwidth and more gain with small antenna size than those of passive antennas. However, AA inherently generates thermal noise and spurious signals from an active device. Moreover, the spurious performance of AA is very important in a highly sensitive receiving system since it is located at the front end of the receiving system. In this study, we developed an AA with $100{\sim}500\;MHz$, having the output P1dB higher than 3 dBm and little spurious signals in real environments. To achieve such performance, we designed an AA with 3-stage amplifier using CD(common drain) FET and 2 BJTs. Its electrical performances were simulated using ADS. The measurement results for typical gain, NF, OIP3, VSWR and P1dB in the required frequency band were 9.7 dBi, 10 dB, 14 dBm, 1.7:1 and 3 dBm respectively. They are in good agreement with simulation results. The unwanted spectrum level of the proposed AA is $10{\sim}30\;dB$ lower than that of the antenna with CS(common source) FET configuration at a west suburban area of Seoul, which shows that the proposed AA can be applicable to a highly sensitive receiving system for detecting unknown weak signals mixed with broadcasting and civilian communication signals.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.6
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• pp.630-639
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• 2008

In this paper, we investigate the cause of throughput degradation on the wireless local area network(WLAN) and the reason of interference level change attributed to the spanned frequency in the presence of electromagnetic interference. We also measured and quantified the electric field strength of interference which yields the abrupt change of the throughput. Two units of WLAN and one unit of AP(Access Point) are configured to maintain the radio link. As the sources of interference, both the co-channel and adjacent-channel interference are considered and the critical values of electric field are provided for each case. Our experimental observations show that the signal strength generated from these interference sources is at most less than 54 dBuV/m @3 m in order to coexist between WLANs and other low power radio devices without any noticeable throughput decreases. Based on our empirical results, as far as 802.11b WLAN is concerned, we believe that the current domestic limit of the signal strength for an extremely low power radio device, 30.9 dBuV/m @3 m, can be increased as much as 23.1 dB.

• Korean journal of communication and information
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• v.35
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• pp.292-328
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• 2006

This study examined Korean Public Relations trend and social acceptance in 1960s. It centers on the acceptance conditions of PR concept, corporate PR and governmental PR. It analyzed PR recognition and practical activities of the general corporations, financial institutions and public corporations in dealing with corporate PR. It also analyzed Korean governmental PR through examining the structure of governmental PR system, PR activities in rural communities and the police. In those days, PR concept had been misused to no small degree and not been accepted correctly that the necessity to let people know PR in its proper meaning was raised. Laying emphasis upon the technical side, corporate PR activities had centered on publicity. Especially, at that time, the banks, the insurance companies and the public corporations had perceived the importance of PR and implemented a set of PR activities. It can be said that a special feature in government PR in 1960s lies in the expansion of the public information system and reinforcement of PR policies. Also, PR in rural communities had been doing to give information relating to agriculture technique and to improve the living conditions of the farm area. The importance of PR in police had been on the side of promoting relations with people and improving treatment of the people by policeman.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1636-1647
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• 2006

The purpose of this study was to provide data that can be used to suggest idealistic anchor's image to capture ratings for the news program and to suggest guide for casting and training anchors for the broadcasting stations by examining the idealistic looks and images of TV news anchors by asking the general viewers who watch TV, The research methods was questionnaire survey. The subjects were 839 male and female audiences in theire 20's and 40's who residing in Seoul and Gyeonggi area. The study results are as follows: 1) The factors that decide impression of a female anchor The factors that decide female anchor's impression were 'specialty factor, friendliness factor, elegance factor, dynamic factor, and attractiveness factor'. 2) The difference in formation of impression according to makeup and hair style of a female anchor In case of specialty and friendliness factors scored high when putting on natural makeup, dynamic factors scored high when putting on elegant makeup, and attractiveness factor when putting on natural and romantic makeup. All factor were high when a female anchor had short-cut style and straight hair 3) Formation of anchor's impression from makeup and hair style according to the perceiver's variables (gender and age) Male and female audiences both gave hish score for a female anchor's specialty such as 'confident and reliable' and friendliness such as 'warm and comfortable' when a female anchor puts on natural makeup. They gave high score for attractiveness factor such as' good impression and refined' when putting on romantic makeup and high score for dynamic factor such as 'positive and confident' when putting on elegant makeup. Both male and female audiences gave high score fur all except friendliness factor when a female anchor had short-cut style compared to bobbed hair and high score far specialty factor when a female anchor had straight hair. The audiences both in their 20's and 40's gave high score for specialty and friendliness when a female anchor put on natural makeup while the perceivers at their 20's gave high score for elegance and dynamic factor when a female anchor put on elegant makeup. The audiences both in their 20's and 40's gave high score for all factors when female anchor had short-cut hair.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.1-7
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• 2020

In modern society, as technology has advanced and human life area has expanded, there has been an increasing demand for high-quality voice and video communications services without restrictions on time and place. In response to this demand, satellite communications systems that provide a wide range of communications and that offer multiple access are evolving day by day. In satellite communications systems such as Digital Video Broadcasting - Return Channel Via Satellite (DVB-RCS) and Warfighter Information Network-Tactical (WIN-T), the multi-frequency time division multiple access (MF-TDMA) demand assigned multiple access (DAMA) scheme is used for efficient resource allocation. In this scheme, since the satellite terminals periodically request resources from the network controller, and the network controller dynamically allocates resources, it is necessary to arrange resource allocation information from time to time. Shortening of the alignment time is a more important factor in a satellite communications system in which a long transmission delay occurs due to long-distance transmission and reception. In this paper, we propose a sorting algorithm variable-selection scheme that shortens the sorting time by cross-selecting the sorting algorithm based on a threshold value, while setting the number of frames in the MF-TDMA DAMA satellite communications system as the threshold value.