• The Journal of the Acoustical Society of Korea
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• v.35 no.2
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• pp.110-117
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• 2016

Passive sonar systems detect and classify the target by analyzing the radiated noises from vessels. If multiple noise sources exist within the sonar detection range, it gets difficult to classify each noise source because mixture of noise sources are observed. To overcome this problem, a beamforming technique is used to separate noise sources spatially though it has various limitations. In this paper, we propose a new method that uses a FDICA (Frequency Domain Independent Component Analysis) to separate noise sources from the mixture. For experiments, each noise source signal was synthesized by considering the features such as machinery tonal components and propeller tonal components. And the results of before and after separation were compared by using LOFAR (Low Frequency Analysis and Recording), DEMON (Detection Envelope Modulation On Noise) analysis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.3
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• pp.265-276
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• 1997

This study was investigated the herbage productivity and nutrient contents of corn (Suweon 19 and Kwanganok) and sweet sorghum (Ramiki sorgo and Silage sorgo) at the stage of maturity (10-DBS, silking, milky and dough stages) to identify the utility value of sweet sorghum as a substituting crop for corn. The silage materials (dough stage) were chopped and were storaged for 90 days in polyethlene bag with O.lmm thickness. Chemical composition, nitrogen content and in vitm dry matter digestibility were evaluated. Also, daily intake and palatability were checked in the feeding trial with four male sheep in average weight about 57kg. Both fresh and dry matter yield of corn and sweet sorghum were increased as the maturity processed (P< 0.05), and sweet sorghum showed higher total yield potential than corn. Crude protein content of the cultivars was decreased as the maturity was processed (P< 0.05). Neutral detergent fiber (NDF) content of the cultivars, in general, showed highest at silking stage, followed by 10 days before silking (10-DBS), and milky and dough stages (Pi0.05) in order. Acid detergent fiber (ADF) content was increased as the maturity processed, and it showed the highest value at milk stage. However, the contents of ADF in sorghum plant was decreased during the late maturity. Crude protein content of the silage was not significantly different among cultivars used, while NDF content was highest in Ramiki sorgo, followed by Silage sorgo, Kwanganok and Suweon 19. In v i m DM digestibility of the silage was highest in Kwanganok, followed by Suweon 19, Silage sorgo and Ramiki sorgo. Total N content of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok. DM intake of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok and it was closely related to the palatability value.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.1
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• pp.147-159
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• 2014

The present study was aimed to estimate the rational bubble by using the state space model and Kalman filter, of the national, capital, non-capital, Gangnam, and Gangbuk regions housing sales price from November 2003 to August 2013, for the whole period, and before and after the global financial crisis. For the whole period, Gangnam marked the highest rational bubble of 25.4%, followed by Gangbuk 21.3%, capital region 20.1%, whole country 18.9%, and non-capital region 14.3%. Prior to the global financial crisis, Gangnam showed 26.7% of bubble, which is approximately 7.4% higher than Gangbuk with 19.3%. On the other hand, after the global financial crisis, the bubble has collapsed a lot with Gangnam 13.2% and Gangbuk 10.7%; however, the non-capital region showed rather an increase of about 15% from 4.2% before the crisis to 9.0% after the crisis. The main cause of this is that the trading price has declined but the rents have risen in the capital region including Gangnam and Gangbuk, while the transaction price has gone up in non-capital region due to various positive signs like the moving of public institutions.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.9
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• pp.503-513
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• 2004

In large distributed systems, replications of data and service are needed to decrease communication cost, increase availability, and avoid single server bottleneck. Tree Quorum protocol is a representative replication protocol, which exploits a logical structure. Tree quorum protocol is one of the replication protocols allowing low read cost only in the best case, while the number of replicas exponentially increases as the level grows. In this paper, thus, we propose a new replication protocol, called symmetric tree protocol which efficiently solves the problem. The proposed symmetric tree protocol also requires much smaller read cost than previous protocols. We conduct cost and availability analysis of the protocols, and the proposed protocol displays comparable read availability to the tree protocol using much smaller number of nodes. Also, the symmetric tree protocol has much smaller response time than the logarithmic protocol.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.316-322
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• 2019

A probabilistic approach considering uncertainties was employed to investigate the effects on the material characteristics and strength of nuclear bio-logical shield concrete walls, when exposed to long-term radiation during the entire service life. Time-dependent compressive and tensile strengths were estimated by conducting the neutron fluence analysis. For the contaminated concrete, individual compressive and tensile failure probabilities can be possibly evaluated by not only establishing limit-state function withthe predefined critical values but also performing Monte Carlo Simulation. Nuclear power plant types similar to the Kori Unit 1, which was shut off permanently in 2017 after the 40-year operation, were herein selected for an illustrative purpose. Consequently, the probability-based performance assessment and prediction of contaminated concrete walls were well demonstrated.

• Analytical Science and Technology
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• v.17 no.4
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• pp.308-314
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• 2004

When the polymer was used for the guard raw materials of electronic device, the content of U, Th and their daughter nuclides were known as a factor of soft error. Because emitted alpha ray could be caused of mis-operation. And ionic impurities such as Cl, Fe, Na could shorten the device life-time. For the analysis of trace impurities in the polymer, neutron activation analysis(NAA) and ICP/AES have been studied. To improve the accuracy and sensitivity of the trace and ultratrace metallic impurities in the epoxy and phenol polymer, sample pretreatment method and optimum analytical condition of NAA were developed. Using the above method, U, Th and other 23 trace impurity elements were analyzed.

• Korean Journal of Oriental Medicine
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• v.17 no.2
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• pp.47-56
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• 2011

Objective : This study reviews the articles about 'Side effect' published in the Japanese Journal of Oriental Medicine to better understand about side effects of herbal medication and to encourage clinicians, the authorities and the public to establish side effects reporting system. Method : We searched articles published in the Japanese Journal of Oriental Medicine by using keyword '副作用(Side effect)' in the CiNii. Results : Among the 118 articles collected, 14 are clinical articles about side effect of prescriptions, 13 are reports about side effect of prescriptions presented from Japanese Ministry of Health, Labour and Welfare, 36 are clinical articles about relief of side effects derived from taking western medicine by taking a herbal prescription, 8 are studies about the effect of a herbal prescription combined with western medicine or comparative studies between a herbal prescription and western medicine, and so on. Conclusions : Lots of articles deal with side effects of Aconiti Lateralis Radix Preparata, Bupleuri Radix and so on. When side effects occurred, removing a certain herbal drug or quitting a herbal prescription is helpful to relieve or disappear the side effects. And Side effects reporting system should be established to guide safe medication use and treatment for patients. In order to establish side effects reporting system, the standardization of herbal drugs is needed.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.235-246
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• 2002

While the Internet is suffering from the massive data such as video stream, IP multicast can ease the load of the Internet by enabling one copy of digital information to be received by multiple computers simultaneously. But If multicast is based on UDP, packets are delivered using a best-effort Policy without any reliability, congestion control or flow control. Multicast group members can join or leave a multicast group at will, and multicast uses broadcast mechanism, it's very hard to keep security from unauthorized members. In this paper, we introduce a new reliable multicast protocol TRDMF proper for one-to-many multicast model with reliability, flow control, congestion control and key management.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.241-250
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• 2006

Ice ring formation, one of the core techniques in LNG storage in a lined rock cavern, is investigated through hydro-thermal coupled analysis. An ice ring acts as a secondary barrier in case of leakage of cryogenic liquid and as a primary barrier for groundwater intrusion into an LNG cavern. Therefore, the thickness and location of the ice ring are crucial factors for the safe operation of an LNG storage cavern, especially for maintaining the integrity of a primary barrier composed of concrete, PU foam, and steel membrane. Through numerical analyses, the position and thickness of the ice ring are estimated, and the temperature and groundwater level are compared with measured values. The temperature md groundwater level by numerical analyses show good agreement with the field measurements when temperature-dependent properties and phase change are taken into account. The schemes used in this paper can be applied for estimation of ice ring formation in designing a full-scale LNG cavern.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.497-505
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• 2004

The proliferation of mesangial cells has been associated with the development of diabetic nephropathy. The cell proliferation has been regulated by diverse growth factors. Among them, insulin like growth factors(IGFs) are also involved in the pathogenesis of diabetic nephropathy. However, it is not yet known about the effect of high glucose on IGF-I and IGF-II secretion and the relationship between high glucose-induced secretion of IGFs and PKC or oxidative stress in the mesangial cells. Thus, we examined the mechanisms by which high glucose regulates secretion of IGFs in mesangial cells. High glucose(25 mM) increased IGF-I and IGF-II secretion. High glucose-induced increase of IGF-I and IGF-II secretion were blocked by taurine($2{\times}10^{-3}$ M), N-acetyl cystein(NAC, $10^{-5}M$), or GSH($10^{-5}M$) (antioxidants), suggesting the role of oxidative stress. High glucose-induced secretion of IGF-I and IGF-II were blocked by H-7, staurosporine, and bisindolylmaleimide I(protein kinase C inhibitors). On the other hand, high glucose also increased lipid peroxide (LPO) formation in a dose dependent manner. In addition, high glucoseinduced stimulation of LPO formation was blocked by PKC inhibitors. These results suggest that PKC is responsible for the increase of oxidative stress in the action of high glucose-induced secretion of IGF-I and IGF-II in mesangial cells. In conclusion, high glucose stimulates IGF-I and IGF-II secretion via PKCoxidative stress signal pathways in mesangial cells.