• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2004.11a
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• pp.17-20
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• 2004

가정 내에 방송과 총신을 통합하여 제공하기 위한 방법으로서 수동광가입자망(Passive Optical Network)이 제안되고 있다 이를 구현하기 위해 여러 방식들이 연구되고 있는데 크게는 방송과 통신에 각기 다른 파장을 이용하는 방식과, 이들을 시간 다중화 하여 한 개의 과장으로 송신하는 방식으로 나눌 수 있다. 또한 동신에 이용하는 과장의 경우 각 가입자에게 다른 파장을 적용하는 WPON 방식과 모든 가입자에게 한 개의 파장만을 이용하되 시간영역에서 다중화하고 이터넷 프로토콜을 적용하는 EPON 방식으로 구분할 수 있다. WPON의 경우 EPON에 비해 수월하게 광대역 서비스를 할 수 있는 장점이 있으나, 각 가입자 과장의 제어 및 관리가 복잡하며, 고비용을 요구한다. 반면 EPON의 경우 채널의 효율성은 극대화할 수 있으나, 동시 이용자가 많을 경우 전송 속도가 하락한다. 한편, 방송과 통신을 통합한 채널의 특성을 살펴보면 가입자 방향으로의 하향 신호의 양이 중양국 방향으로의 상향 신호의 양에 비해 훨씬 많은 비대칭 구조이다. 따라서 본 연구에서는 이러한 채널 특성에 맞도록 하향 전송에는 WPON의 구조를 이용하고, 상향 전송에는 EPON의 구조를 적용하는 새로운 구조의 광가입자망을 제안하였다. 제안된 구조에 적합한 MPCP (Multi-Point Control Protocol) 프로토콜을 제시하고, 가입자 장치의 여러 종속 신호를 다중화하고 전송할 수 있는 ONU (Optical Network Unit)의 구조를 제안하였다. 또한 이러한 구조를 갖는 W-EPON 테스트베드를 구현하고 전송 시험을 통해 제시된 구조의 적합성을 측정한 결과를 보인다.4 Textual format) 파일을 생성한다. 또한, 콘텐츠 전송 및 저장의 효율성을 위해 이진 포멧인 IPMP화된 MP4 파일을 생성할 수 있다.으로써, 에러 이미지가 가지고 있는 엔트로피에 좀 근접하게 코딩을 할 수 있게 되었다. 이 방법은 실제로 Arithmetic Coder를 이용하는 다른 압축 방법에 그리고 적용할 수 있다. 실험 결과 압축효율은 JPEG-LS보다 약 $5\%$의 압축 성능 개선이 있었으며, CALIC과는 대등한 압축률을 보이며, 부호화/복호화 속도는 CALIC보다 우수한 것으로 나타났다.우 $23.87\%$($18.00\~30.91\%$), 갑폭 $23.99\%$($17.82\~30.48\%$), 체중 $91.51\%$($58.86\~129.14\%$)이였으며 성장율은 사육 온도구간별 차는 없었다.20 km 까지의 지점들(지점 2에서 지점 6)에서 매우 높은 값을 보이며 이는 조석작용으로 해수와 담수가 강제혼합되면서 표층퇴적물이 재부유하기 때문이라고 판단된다. 영양염류는 월별로 다소의 차이는 있으나, 대체적으로 지점 1과 2에서 가장 낮고, 상류로 갈수록 점차 증가하며 지점 7 상류역이 하류역에 비해 높은 농도이다. 월별로는 7월에 규산염, 용존무기태질소 및 암모니아의 농도가 가장 높은 반면에 용존산소포화도는 가장 낮다. 그러나 지점 14 상류역에서는 5월에 측정한 용존무기태질소, 암모니아, 인산염 및 COD 값이 7월보다 다소 높거나 비슷하다. 한편 영양염류와 COD값은 대체적으로 8월에 가장 낮으나

• Applied Biological Chemistry
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• v.25 no.3
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• pp.135-141
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• 1982

Two rice cultivars, Jinju and Iri 348, were used to compare the changes in the contents of some organic metabolites and ions and in some enzyme levels under water-and salt-stressed conditions. The water loss and proline accumulation under water and salt stresses were accelerated more in the salt-sensitive cultivar Iri 348 than in the salt-tolerant Jinju. The contents of crude protein, total free amino acids, proline and polyphenols increased under water-or salt-stressed rice, but that of reducing sugar increased under water stress only. The water-and salt-stresses induced the high ratio of low molecular organic solutes to crude protein in Jinju but not in Iri 348. The ratio of total free amino acids to crude protein increased under the stressed conditions was likely due to high protease activity. The contents of $Na^+$ and $Cl^-$ were higher in Iri 348 than in Jinju. Iri 348 had higher values of $Na^+/Ca^{2+}$ and monovalent/divalent of cations, but lower of $K^+/Na^+$ than Jinju Rice. The further studies should emphasize to set the correlations between these ratios and tolerance to water and salt stresses among rice cultivars.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.74-79
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• 2014

The purpose of this study was to determine the efficacy of Aster koraiensis Nakai as a natural health food source. To accomplish this, the general and antioxidative contents of A. koraiensis were measured. Total contents of carbohydrates, crude protein, crude lipid, and ash were 72.15%, 13.49%, 5.09%, and 9.27%, respectively. Caloric content of A. koraiensis was 349.70 kcal, while total dietary fiber was 49.79%. Total proteins consisted of 18 different kinds of amino acids. Contents of essential and non-essential amino acids were 4.6 and 5.5 g/100 g, respectively. Regarding mineral contents, P was the most abundant mineral, followed by K, Ca, and Na. Therefore, A. koraiensis is an alkali material. Total phenol contents of the hot water and 80% ethanolic extracts of A. koraiensis were $87.7{\pm}5.01$ and $112.4{\pm}3.41$ mg GAE/g, respectively. Total flavonoid contents of the hot water and 80% ethanolic extracts were $86.6{\pm}3.71$ and $95.1{\pm}8.00$ mg RE/g, respectively. The DPPH radical-scavenging activity and reducing power of the 80% ethanolic extract of A. koraiensis were higher than those of the water extract. Therefore, the general nutrients and antioxidant bioactive materials in A. koraiensis are potential materials for health foods.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.936-944
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• 2019

Submarines, which have been called an invisible force, are strategic underwater weapon systems that perform missions such as anti-surface warfare, anti-submarine warfare, and high payoff target strikes with the advantage of underwater covertness. A submarine should be able to withstand the hydrostatic pressure of the deep sea. In this respect, the submarine pressure hull, as the main structural system to resist the external pressure corresponding to the submerged depth, should ensure the survivability from hazards and threats such as leakage, fires, shock, explosion, etc. To do this, the initial scantling of the submarine pressure hull must be calculated appropriately in the concept design phase. The shape of the aft transition ring varies according to its connection with the submarine aft end conical structure, pressure hull cylindrical part, and non-pressure hull of the submarine; the design of the aft transition ring should not only take into account stress flow and connectivity but also the cost increase due to the increased man-hours of its complex geometry. Therefore, trade-off studies based on the four different shapes of the aft transition ring are carried out considering both the review of the structural strength through nonlinear finite element analysis (FEA) and economic feasibility by reviewing the estimations of the manufacturing working days and material costs. Finally, the most rational structural aft transition ring shape for a submarine amongst four reviewed types was proposed.

• Applied Biological Chemistry
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• v.16 no.1
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• pp.41-48
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• 1973

1. Through out the entire stage of growth, the amount of nutrients, number of tillers and of spikes increased in the Simagcalin treated plot as compared with the control. The treated plot showed healthul growth at the later growing stage. On the other hand, management of irrigation water resulted in raised the grain straw ratio and retarded the culm height about 10%. 2. Application of Simagcalin greatly increased the content of phosphorus and magnesium at the harvesting time. The culm and sheath analyses are recommendable for the determination of magnesium deficiency. 3. The controled irrigation would effect root activity as the main factor, and Simagcalin might act as a secondary factor. 4. While the application of phosphorus may not affect the yield components, The basic elements in Simagcalin may enhance the uptake of nutrients under heavy application of nitrogn.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.225-237
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• 1990

Various chemical constituents were measured from April to August 1988 at the down-ward 20 stations of Keum River, which is located in the Midwest of Korea, to understand the characteristics of water quality with respect to spatio-temporal variations of each constituent. The 24-hrs continuous measurements with 2-hrs interval were made simultaneously at station 2 near the estuary weir and station 9(Ganggyeong) of 35 km upstream from the weir in April. By the results observed for one day in April at station 2, salinity has a range of $7.88\~22.14\%_{\circ}$ and its temporal variability is identical to the pattern of tidal cycle in the neigh-bouring Kunsan Harbor. However, turbidity shows relatively high values only at an interval of 4~5 hours after the lowest salinity time, though hourly fluctuation of pH is very small. Silicate and dissolved inorganic nitrogen have inversively linear correlationships with salinity, implying the concentration of the two nutrients strongly regulated by estuarine mixing of sea and river waters. In contrast, phosphate sustains roughly a constant level over a wide salinity range and distinctly lower values than those corresponding to nitrate in the oceans. Such distributions of phosphate have been observed in some estuaries, and interpreted as driven by removal of dissolved phosphate into bottom sediments and the bufforing of phosphate by particulate matter. COD values at station 2 are relatively high in day-time(particularly afternoon) and in high-salinity periods. At station 9, saltwater intrusion was never found but water level changed to the extent of 2.5 m for one day. Although each parameter at this station exhibits very slight variations in their abundance for 24 hours compared with station 2, the contents of COD, silicate and ammonia are significantly higher than at station 2. Concentration of suspended matter is relatively high in the brackish water region up to $\~20$ km above the river mouth, probably due to strong tidal stirring of the bottom de-posits. Also, relatively high pH, COD and $O_2$ saturation at the upward stations of $40\~50$ km from the weir are presumably attributable to active photosynthesis of plants in the region. In general, COD and nutrients except phosphate are higher values at the upper stations than in the estuary zone, and show the highest abundances in July nearly at all stations. Finally, in the estuarine region tidal mixing of sea-river waters seems to be an important factor controlling the distributions of turbidity, COD, silicate and nitrate as well as salinity. However, water quality in the upward fresh-water zone is remarkably variable according to months or seasons.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.173-181
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• 1993

Seasonal distributions of nutrients and particulate organic matter were investigated in Asan Bay, Korea. Most of nutrients were high in August and low in February. The atomic ratios of inorganic nitrogen to phosphorous were close to Redfield ratio except in May when the ratio was 24.8. In May, nutrient concentrations except phosphorous decreased with salinity until $31.5{\sim}32.0%0$, but the concentrations increased again with salinity, impling that there were nutrient input sources within the estuary. Howerer, significant inverse relationships between nutrients and salinity in August suggest that nutrient sources were river discharge. Maximum chlorophyll a concentrations occurred in May. Relatively low ratios of $R_b$ to $R_a$($R_b$: fluorescence before acidification; $R_a$: fluorescence after acidification) during the study periods indicate that phytoplankton were not in good physiological condition. Relatively low ratio of particulate biogenic silica(PBSi) to particulate organic carbon(POC) and high ratios of PBSi and POC to chlorophyll a during the study periods suggest input of non-living detrital PBSi and POC from bottom in Asan Bay, where strong tidal mixing occurs.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.98-102
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• 2012

These days, Uncooled IR Systems are more popular in the area of defense and aerospace than before. Uncooled IR Systems are widely used as core technology for making unmanned systems and detecting enemy objects during the day and night in the distance. Recently, researches on TEC-less IRFPA have been increased to minimize the power consumption and to make a smaller system than before. For this, it needs to find adequate NUC(Non-Uniformity Correction) coefficients as FPA(Focal Plane Array) temperature changes. In this paper, we propose a new NUC coefficient estimating technique, DCCE-LI(Dynamic Calibration Coefficients Estimation with Linear Interpolation), for TEC-less IRFPA. It is based on a linear interpolation method and it can estimate NUC coefficients in real-time. So, by testing and evaluating it with some IR images, we conclude that the quality of IR images using proposed method is better than applying static coefficients.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.43-50
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• 2008

This study was conducted to investigate the proper supplied conditions of sodium selenate supplied by fertigation to improve functionality of major western vegetables; beet, broccoli, cabbage lettuce, celery, and parsley in highland. In this work, the growth and content of minerals, ascorbic acid, nitrate, and selenium were measured in western vegetables that treated sodium selenate by different concentration, treatment time and treatment frequency. While there was not different in early growth of some western vegetables among different concentration of sodium selenate; 1,2, 5 and $20\;mg{\cdot}L^{-1}$, at 20 days after treatment, the fresh weight was reduced 33% at cabbage lettuce,47% at broccoli, and 74% at parsley compared control in $5\;mg{\cdot}L^{-1}$ treatment. But the fresh weight of beet and celery reduced just 20% and 15% compared control in even $20\;mg{\cdot}L^{-1}$. The ascorbic acid of cabbage lettuce, celery, and beet increased as sodium selenate concentration increased, so that of cabbage lettuce showed 1.2 times compared control in $20\;mg{\cdot}L^{-1}$ treatment and also that of beet and celery increased 10%. But the ascorbic acid of broccoli and parsley was not influenced by treated sodium selenate. As the concentration of sodium selenate increased, the nitrate contents decreased regardless of crops compared control. This reduced effect of nitrate was highest in cabbage lettuce, followed by beet and celery. The mineral contents, such as K, Ca, and Mg, decreased in all crops, as the concentration of sodium selenate increased. The potassium content showed an obvious negative correlationship with the concentrations of sodium selenate regardless of crops, but the magnesium and calcium content did not show significant difference between treatments. The selenium content increased in proportion as increasing sodium selenate concentrations. The broccoli, celery and parsley treated $20\;mg{\cdot}L^{-1}$ sodium selenate showed 24.4 times, 76.4 times, and 560 times higher than control, respectively. When the sodium selenate supplied to some western vegetables in different growth stage, the selenium content increased 1.3 times and 1.4 times higher in early stage than in late stage in cabbage lettuce and broccoli, respectively. However in parsley and celery, the selenium content showed the highest in middle stage. The selenium content increased in proportion as increasing the sodium selenate treatment frequency, but in above 10 times treatment, the increased effect alleviated in parsley, celery, and cabbage lettuce. On the contrary, the selenium content of broccoli increased constantly as treatment frequency increased.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.13-22
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• 2003

This pot experiment was conducted to find out the forage productivity and mineral contents in an orchardgrass sward affected by the compost, lime, and phosphorus applications on the newly reclaimed and arable pasture soils. This 3rd part was concerned with the effect of phosphorus application($P_{0}$ : control, $P_1$=1.25ｇ, $P_2$=2.50g, $P_3$=3.75g $P_2$$O_{5}$ pot). The results obtained are summarized as fellows; There were considerable differences between the newly reclaimed and arable pasture soils in the soil chemical characteristics as follows in general; poor~common in the newly reclaimed soil and common~good in the arable pasture soil in terms of soil fertility standard. Comparing with the arable pasture soil, the contents of available$ P_2$$O_{5}$ / in the newly reclaimed soil at end of experiment were considerably increased by the $P_2$$O_{5}$ applications, These effects in the newly reclaimed soil were positively influenced by the additional application of compost, but were adversely influenced by the additional application of lime. The seedling vigour and yield of orchardgrass were far better in the arable pasture soil than in the newly reclaimed soil. At the $P_{0}$ treatment, those were very poor in 也e newly reclaimed soil, but were good in the arable pasture soil. Comparing with $P_1$ treatment, the above effects of heavy $P_2$$O_{5}$ / applications($P_2$and $P_3$) were not recognized. On the newly reclaimed soil, the above effects were markedly enhanced by the applications of $P_2$$O_{5}$ with compost. The Ca, Mg, and P contents of orchardgrass were relatively higher on the arable pasture soil than on the newly reclaimed soil, whereas ere were no differences in the K contents.