• 한국해양학회지
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• v.5 no.1
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• pp.14-29
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• 1970

Tidal variations of various chemical constituents in the laver bed sea waters in Wan Do Gun were determined over one spring tidal cycle from Oct. 1968 to Feb. 1969. Total ranges and means of the contents at Pyung-il Do and Wan Do are as follows. Although the average monthly variations of each content at Pyung-il Do were similar to those at Wan Do, most of the contents at Pyung-il Do were at a slightly higher level than at Wan Do. The values of silicate-silicon, phosphate- phosphorus and soluble iron, however, showed high levels at Wan Do. Chlorinity, magnesium, calcium, dissolved oxygen, silicate-silicon and phosphate-phosphorus contents increased from Oct. 1968 to Feb. 1969, though the content of soluble iron decreased before December and slightly increased in January and February. The average monthly variations of ammonia-nitrogen and nitrate-nitrogen contents were irregular. The nitrite-nitrogen content appeared in trace amounts in the months with a comparatively high water temperature, i.e., October and November, but in midwinter it was undetected. The ranges of the tidal variations of the contents of each chemical constituent were not significantly wide, though the contents varied excessively by the hour, and this may show the irregularity of the water quality in Wan Do Gun coastal area. As a rule, no regular tidal variation of the chlorinity was observed except slightly decreased value at ebb tide at Wan Do. In general, although the pattern of the variations of calcium and magnesium contents were similar to that of the chlorinity, no definite relationships between these constituents and chlorinity were observed. Tidal variations of the dissolved oxygen content, nutrient salts and soluble iron were irregular.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.5
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• pp.662-670
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• 2005

Statement of problem: Little is known about the effect of abutment preparation procedure on do-torque values in different implant platform and the relationship of final do-torque values with different implant platform size. Purpose: This study evaluated the effect of abutment preparation procedure on do-torque values in different implant platform and the relationship of final do-torque values with different implant platform size. Material and method: Six ITI implants (2 narrow-neck implants, 2 regular-neck implants, 2 wide-neck implants) and six Branemark implants (2 narrow platforms, 2 regular platforms, 2 wide platforms) were embedded in each acrylic resin block with epoxy resin. Eighteen $synOcta^(R)$ abutments (6 narrow-neck implant-abutments, 6 regular-neck implant-abutments, 6 wide-neck implant-abutments) and eighteen esthetic abutments (6 narrow platform-abutments, 6 regular platform-abutments, 6 wide platform-abutments) were tightened to each implant with digital torque gauge. Initial do-torque values were measured using digital torque gauge. After preparation of abutments, Final do-torque values were measured with digital torque gauge. Results and conclusion: 1. Screws loosening or abutments motion were not detected in all experimental group, but some scratches of implant-abutment joints were detected in all group 2. Reduction ratios of final do-torque values were greater than initial do-torque values in all measured group, except in narrow-neck implant-abutment group (p<0.05). 3. Reduction ratios of final do-torque values in wide-neck implant-abutment group were greater than regular-neck implant-abutment group (p<0.01). 4. The greatest standard deviation value was detected in wide platform group in both implant systems.

• Journal of Species Research
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• v.2 no.2
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• pp.203-222
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• 2013

The district of Ganghwa-gun in the western coast (Seohae) of the Korea is consisted of several islands, Ganghwa-do, Seokmo-do, Gyodong-do, Jumun-do, Boreum-do, Seogeom-do and Donggeom-do. Since several islands of them were connected to mainland of Korea by bridges, the islands attract a lot of tourists from Seoul, Incheon and Gyeonggi-do areas. Construction of new roads, pensions, resort areas and restaurants provided economical benefits to local residents while natural vegetation of these islands has deteriorated continuously. Before biodiversity of vascular plants in these regions is damaged seriously by human impacts, it is needed to conserve original vegetation of the islands for restoration and monitoring in the future. Therefore, the primary purpose of the study is to clarify the flora of Donggeom-do, belonging to Ganghwa-gun. From the 15 times of field trips to the island, we have collected a number of vascular plants, 512 taxa in total, including 110 families, 329 genera, 449 species, six subspecies, 52 varieties, four forms and one hybrid. Of 512 taxa investigated, we have identified 12 taxa to be endemic to Korea. Six taxa were endangered or rare species which were designated by the Ministry of Environment and Korea Forest Service, respectively. 25 taxa were recognized as floristic regional indicator species designated specially by the Ministry of Environment. Seven species have shown their northern or southern distributional limit ranges, and 29 taxa were recognized as halophytes. The naturalized plants were identified as 55 taxa, and their naturalization ratio was 10.7%.

• Journal of Aerospace System Engineering
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• v.14 no.spc
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• pp.13-21
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• 2020

RTCA DO-178C is a development guideline to ensure aircraft system airworthiness. However, there is an opinion that the application of DO-178C to the development of UAV of more than MTOW 150 kg is over regulated because the severity of the risk from UAV is lower than that of normal aircraft. To address issue, EASA and FAA have been working on the Re-Engineering and Streamlining the Standards for Avionics Certification(RESSAC) project since 2016 with the goal of establishing a new certification scheme that simplifies existing aircraft certification procedures and standards. This paper analyzes the current DO-178C certification process and presents advantages by comparing and analyzing the new RESSAC certification process, which simplifies processes and outputs in comparing with the DO-178C certification process, while it ensures flight safety of the vehicle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.309-312
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• 2016

Considering that interkorean relations got worse and worse recently, cyber terror of North Korea has seriously become a possibility. Therefore, DoS(Denial of Service), a typical way of cyber terror, is becoming a big issue. Consequently, people are growing more and more interested in information security. Internal DoS attacks, out of a variety of ways of Dos attacks, include disks and memories and shortages of process resources. PAM(Pluggable Authentication Module) is one of the ways of preventing internal DoS attacks in Linux system. This paper provides with a method to internally respond to dos attacks and efficiently prevent shortages of resources by utilizing PAM.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.223-229
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• 2010

This study is to analyze location conditions for erosion control dams to be constructed in Chungcheongnam-do, Daejeon Metropolitan City, Chungcheongbuk-do and Gyeongsangbuk-do in order to establish proper conditions for erosion control dams in the future. 199 sites where erosion control dams are expected to be built in 2010 were chosen and investigated in terms of 12 factors including basin area, basin slope, and landslide risk. The results showed that erosion control dams for Chungcheongnam-do and Daejeon Metropolitan City are mostly impermeable gravity dams mainly composed of concrete. In contrast, Chungcheongbuk-do and Gyeongsangbuk-do are increasing the number of permeable or compound erosion control dams. Basin analysis at planned erosion control dam sites showed that at least 44.5% of the total area has high landslide risk. Gyeongsangbuk-do had the largest basin area for erosion control dam sites at 157.3ha, followed by Chungcheongbuk-do at 64.4ha and Chungcheongnam-do at 54.8ha. Analysis of sand deposits in the Chungcheongnam-do erosion control dam built in 2010 confirmed an average deposit of 971.8m3. The sand deposit capacity and amount of sediment control for erosion control dams have a very low correlation with basin area or flow path slope, and this needs to be addressed in future sand deposit capacity designs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.598-604
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• 2004

The mobile service was focused on voice and low rate data service. But recently high data rate service is getting more important, so mobile service operators are providing 1x EV-DO services for high data rate service. Many mobile repeaters were deployed for service coverage, but most of them were deployed when voice and low rate data service were main service. It is necessary to test whether these repeaters are suitable for 1x EV-DO networks for high rate data services. In field test, 1x EV-DO data rates were measured through various repeaters. Some repeaters showed data rates degradation compared with 1x EV-DO AN. The specifications of the repeaters were analyzed. And under the various radio environments such as fading and RSSI, data rates through repeater were tested. These test results will be useful for operation guide of repeaters in high data rate service networks.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.694-701
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• 2020

Objectives: The main purpose of this study is to evaluate heavy metal concentrations (Cd, As, Hg, Pb, Cr6+), particle size distribution, hydrochloric acid solubility, and parasite eggs in sand in five non-designated sandy beaches in Gyeonggi Province. Methods: The sampling sites are five non-designated Gyeonggi-do sandy beaches located in Ansan and Hwaseong. ICP-OES and UV, a Vibratory Sieve Shaker, and PCM were respectively used to analyze heavy metal concentrations, particle size distribution, and parasite eggs in the sand. Results: Heavy metals were detected within the beach's safety management standards and some of the detected As and Pb before and after beach opening were lower than one-quarter of the average value. In addition, the results of the T-test to confirm the As and Pb concentration changes before and after opening showed a significant difference in some beaches. The composition of sand was 86.53% according to the particle size distribution standard (2.0-0.02 mm), and the hydrochloric acid solubility was the highest at Gubongsolsup (4.9%) and the lowest at Bangameo-li (0.2%). Parasite eggs were undetected in all beach sand before and after opening. Conclusions: The safety of heavy metal concentrations in sandy beaches was secured in the selected five beaches in Gyeonggi Province. However, continuous efforts are required to make Gyeonggi-do's beaches suitable according to the Act on the Use and Management of Beaches.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.16-23
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• 2022

BACKGROUND: Rice production by the current standard cultivation method is predicted to decrease due to global warming. It seems that there has been a strong warming trend in Hwaseong-si, Gyeonggi-do. This study attempted to understand the climate change in Hwaseongsi, Gyeonggi-do and to analyze the effect of climate change on rice production. METHODS AND RESULTS: The statistical and physicochemical analyses were performed using the rice cultivar 'Chucheongbyeo' yields grown at the rice paddy field plot in the Gyeonggi-do Agricultural Research and Extension Services and the weather data measured in near the rice paddy plot. CONCLUSION(S): There was no significant difference between the average rice yields per area in 2000s (2001~2010) and 2010s (2011~2020), but the rice yield variability was greater in 2010s than in 2000s. The mean, minimum, maximum temperature, and the sunshine hours were evaluated for the correlation with the rice yield. The understanding of climate change in Hwaseong-si, Gyeonggi-do and the major weather factors affecting changes in rice yield, presented in this study, would enhance scientific understanding of regional climate change, and improve rice cultivation management.

• The Journal of Korean Medical History
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• v.15 no.2
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• pp.135-150
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• 2002

In oriental medicine, 'Mack' is the most important medical method of human body. From Wangsukhwa's "Mackkyung" in Jin dynasty to "mackjinki" in modern technology, medical use of mack is so wide. Over the years, many 'pulsation' books had published. Among them, Koyangsaeng's "ChanDoMackKyul" had an influence on many doctors. But also many doctor criticized his book for the absence of orthodoxy. In the middle of chosun era, Hur jun published "Chan Do Bang Ron Mack Kyul Gip Seong". "Chan Do Bang Ron Mack Kyul Gip Seong" had been used from the beginning to the end of the Chosun Dynasty. "Chan Do Bang Ron Mack Kyul Gip Seong" is the medical book that The King 'Seon-jo' ordered to make Hur jun for correcting the faultiness of pulse medical book(ChanDoMackKyul). through the inquiry of it, we expect accomplishment of 'Pulsation' in Chosun Dynasty and reveal the koyangsaeng's date.