• Title/Summary/Keyword: Open Ratio

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Non-Gaussian feature of fluctuating wind pressures on rectangular high-rise buildings with different side ratios

  • Jia-hui Yuan;Shui-fu Chen;Yi Liu
    • Wind and Structures
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    • v.37 no.3
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    • pp.211-227
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    • 2023
  • To investigate the non-Gaussian feature of fluctuating wind pressures on rectangular high-rise buildings, wind tunnel tests were conducted on scale models with side ratios ranging from 1/9~9 in an open exposure for various wind directions. The high-order statistical moments, time histories, probability density distributions, and peak factors of pressure fluctuations are analyzed. The mixed normal-Weibull distribution, Gumbel-Weibull distribution, and lognormal-Weibull distribution are adopted to fit the probability density distribution of different non-Gaussian wind pressures. Zones of Gaussian and non-Gaussian are classified for rectangular buildings with various side ratios. The results indicate that on the side wall, the non-Gaussian wind pressures are related to the distance from the leading edge. Apart from the non-Gaussianity in the separated flow regions noted by some literature, wind pressures behind the area where reattachment happens present non-Gaussian nature as well. There is a new probability density distribution type of non-Gaussian wind pressure which has both long positive and negative tail found behind the reattachment regions. The correlation coefficient of wind pressures is proved to reflect the non-Gaussianity and a new method to estimate the mean reattachment length of rectangular high-rise building side wall is proposed by evaluating the correlation coefficient. For rectangular high-rise buildings, the mean reattachment length calculated by the correlation coefficient method along the height changes in a parabolic shape. Distributions of Gaussian and non-Gaussian wind pressures vary with side ratios. It is inappropriate to estimate the extreme loads of wind pressures using a fixed peak factor. The trend of the peak factor with side ratios on different walls is given.

Design of Reconfigurable Dual Polarization Patch Array Antenna (재구성 이중편파 패치 배열 안테나 설계)

  • Won Jun Lee;Young Jik Cha
    • Journal of Advanced Navigation Technology
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    • v.27 no.4
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    • pp.463-468
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    • 2023
  • In this paper, we proposed reconfigurable dual polarization patch array antenna that can select two polarizations(Vertical, RHCP) using defected ground structure and Pin diode. The proposed antenna was designed arranging a circular polarization patch antenna implemented with a square microstrip patch and two slots 3x3 at 25.8mm placed, a half-wavelength of 5.8 GHz. Conect the pin diode and the capacitor to the slot diagonally placed on the ground of each antennas, and select polarization using the open/short operating according to the application of DC voltage to the pin diode. As a result of the design, the gain of the antenna is 11.7 dBi at vertical polarization and 11.6 dBic at RHCP. The axial ratio is 20.3 dB at 1.8 dB vertical polarization at RHCP. Mutual Coupling is Maximum to -20.8 dB for vertical polarization and Maximum to -30.1 dB for RHCP.

A Study on Impact of Geopolitical Risk on Port Throughput in Korea (지정학적 위기가 항만 물동량에 미치는 영향에 관한 연구)

  • Hyung-Sik Nam;Stephane Ahoua;Chi Yeol Kim
    • Journal of Navigation and Port Research
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    • v.47 no.4
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    • pp.239-245
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    • 2023
  • This study examined the impact of geopolitical risk on port throughput in Korea. With a high trade-to-GDP ratio, Korea has an open economy. The vast majority of its exports and imports are serviced by maritime transport. Therefore, cargo volume of Korean seaports is highly likely to be affected by changes in global economy resulting from escalation in geopolitical risk. In this regard, this study investigated the relationship between geopolitical risk and port throughput in Korea during the period of 1995-2022. Results indicated that the impact of geopolitical risk on port throughput was not statistically significant. However, the relationship varied by export, import, and ports. Especially, it was revealed that cargo volume of Korean ports was negatively associated with the level of geopolitical risk. In addition, it was also found that geopolitical risk had a negative impact on the unit price of Korean import..

C4orf47 is a Novel Prognostic Biomarker and Correlates with Infiltrating Immune Cells in Hepatocellular Carcinoma

  • Hye-Ran Kim;Choong Won Seo;Sang Jun Han;Jongwan Kim
    • Biomedical Science Letters
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    • v.29 no.1
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    • pp.11-25
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    • 2023
  • In hepatocellular carcinoma (HCC), chromosome 4 open-reading frame 47 (C4orf47) has not been so far investigated for its prognostic value or association with infiltrating immune cells. We performed bioinformatics analysis on HCC data and analyzed the data using online databases such as TIMER, UALCAN, Kaplan-Meier plotter, LinkedOmics, and GEPIA2. We found that C4orf47 expression in HCC was higher compared to normal tissues. High C4orf47 expression was associated with a worse prognosis in HCC. The correlation between C4orf47 and infiltrating immune cells is positively associated with CD4+T cells, B cells, neutrophils, macrophages, and dendritic cells in HCC. Moreover, high C4orf47 expression was correlated with a poor prognosis of infiltrating immune cells. Analysis of C4orf47 gene co-expression networks revealed that 12501 genes were positively correlated with C4orf47, whereas 7200 genes were negatively correlated. The positively related genes of C4orf47 are associated with a high hazard ratio in different types of cancer, including HCC. Regarding the biological functions of C4orf47 gene, it mainly regulates RNA metabolic process, DNA replication, and cell cycle. The C4orf47 gene may play a prognostic role by regulating the global transcriptome process in HCC. Our findings demonstrate that high C4orf47 expression correlates with poor prognosis and tumor-infiltrating immune cells in HCC. We suggest that C4orf47 is a novel prognostic biomarker and potential immune therapeutic target for HCC.

Proposed Message Transit Buffer Management Model for Nodes in Vehicular Delay-Tolerant Network

  • Gballou Yao, Theophile;Kimou Kouadio, Prosper;Tiecoura, Yves;Toure Kidjegbo, Augustin
    • International Journal of Computer Science & Network Security
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    • v.23 no.1
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    • pp.153-163
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    • 2023
  • This study is situated in the context of intelligent transport systems, where in-vehicle devices assist drivers to avoid accidents and therefore improve road safety. The vehicles present in a given area form an ad' hoc network of vehicles called vehicular ad' hoc network. In this type of network, the nodes are mobile vehicles and the messages exchanged are messages to warn about obstacles that may hinder the correct driving. Node mobilities make it impossible for inter-node communication to be end-to-end. Recognizing this characteristic has led to delay-tolerant vehicular networks. Embedded devices have small buffers (memory) to hold messages that a node needs to transmit when no other node is within its visibility range for transmission. The performance of a vehicular delay-tolerant network is closely tied to the successful management of the nodes' transit buffer. In this paper, we propose a message transit buffer management model for nodes in vehicular delay tolerant networks. This model consists in setting up, on the one hand, a policy of dropping messages from the buffer when the buffer is full and must receive a new message. This drop policy is based on the concept of intermediate node to destination, queues and priority class of service. It is also based on the properties of the message (size, weight, number of hops, number of replications, remaining time-to-live, etc.). On the other hand, the model defines the policy for selecting the message to be transmitted. The proposed model was evaluated with the ONE opportunistic network simulator based on a 4000m x 4000m area of downtown Bouaké in Côte d'Ivoire. The map data were imported using the Open Street Map tool. The results obtained show that our model improves the delivery ratio of security alert messages, reduces their delivery delay and network overload compared to the existing model. This improvement in communication within a network of vehicles can contribute to the improvement of road safety.

Effect of neem leaves and stock density of earthworm (Eisenia fetida) on quality of rice straw vermicompost

  • Sapna Yadav;Parveen Kumar
    • Advances in environmental research
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    • v.12 no.1
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    • pp.51-64
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    • 2023
  • The sustainable management of rice straw is essential for protection of human health and environment. This study assesses the impact of stock density of earthworm (Eisenia fetida) and Neem leaves (Azadirachta indica) on the quality of the final vermicompost. The vermicompost is produced using different combinations of rice straw, Neem leaves, and cow dung (bulking agent) by varying stock density of earthworms. The vermicomposting experiments are performed in plastic containers (32 cm × 28 cm × 28 cm) in open for 90 days under laboratory conditions. The stock density of the earthworm is found to be an important factor to influence nutritional quality of the final vermicompost. There is observed significant improvement in the total nitrogen (91.8%), phosphate (73.4%), potassium (38.8%), and calcium (59.05%) content of the vermicompost produced with the highest stock density of the earthworms. All the treatments showed decrease in TOC and C:N content after 90 days of vermicomposting. The treatment with Neem leaves showed maximum growth of earthworms (2.65 fold). Neem leaves brought positive changes in the quality of final vermicompost by enhancing the growth and reproduction of the earthworms. The calcium content increased by 39% in the final vermicompost with the addition of Neem leaves at the same stock density of the earthworms. The stock density of the earthworms and Neem leaves are found to significantly improve quality of the final vermicompost as compared with the compost (control). The surface morphology in SEM images showed high degree of fragmentation in the vermicompost as compared with the compost. The combined action of microbes and earthworms resulted in high degree of disintegration in the vermicompost.

In Situ Sensing of Copper-plating Thickness Using OPD-regulated Optical Fourier-domain Reflectometry

  • Nayoung, Kim;Do Won, Kim;Nam Su, Park;Gyeong Hun, Kim;Yang Do, Kim;Chang-Seok, Kim
    • Current Optics and Photonics
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    • v.7 no.1
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    • pp.38-46
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    • 2023
  • Optical Fourier-domain reflectometry (OFDR) sensors have been widely used to measure distances with high resolution and speed in a noncontact state. In the electroplating process of a printed circuit board, it is critically important to monitor the copper-plating thickness, as small deviations can lead to defects, such as an open or short circuit. In this paper we employ a phase-based OFDR sensor for in situ relative distance sensing of a sample with nanometer-scale resolution, during electroplating. We also develop an optical-path difference (OPD)-regulated sensing probe that can maintain a preset distance from the sample. This function can markedly facilitate practical measurements in two aspects: Optimal distance setting for high signal-to-noise ratio OFDR sensing, and protection of a fragile probe tip via vertical evasion movement. In a sample with a centimeter-scale structure, a conventional OFDR sensor will probably either bump into the sample or practically out of the detection range of the sensing probe. To address this limitation, a novel OPD-regulated OFDR system is designed by combining the OFDR sensing probe and linear piezo motors with feedback-loop control. By using multiple OFDR sensors, it is possible to effectively monitor copper-plating thickness in situ and uniformize it at various positions.

Korean red ginseng water extract produces antidepressant-like effects through involving monoamines and brain-derived neurotrophic factor in rats

  • Tzu-wen Chou ;Huai-Syuan Huang;Suraphan Panyod ;Yun-Ju Huang ;Lee-Yan Sheen
    • Journal of Ginseng Research
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    • v.47 no.4
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    • pp.552-560
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    • 2023
  • Background: Ginseng Radix (Panax ginseng Meyer, Araliaceae) has been used medicinally to treat the brain and nervous system problems worldwide. Recent studies have revealed physiological effects that could potentially benefit cognitive performance or mood. The present study aimed to investigate the antidepressant effects of Korean red ginseng water extract (KGE) and its active component in an unpredictable chronic mild stress (UCMS)-induced animal model and elucidate the underlying mechanisms. Methods: The antidepressant potential of the UCMS model was evaluated using the sucrose preference test and open field tests. The behavioral findings were further corroborated by the assessment of neurotransmitters and their metabolites from the prefrontal cortex and hippocampus of rats. Three doses of KGE (50, 100, and 200 mg/kg) were orally administered during the experiment. Furthermore, the mechanism underlying the antidepressant-like action of KGE was examined by measuring the levels of brain-derived neurotrophic factor (BDNF)/CREB, nuclear factor erythroid 2-related factor 2 (Nrf2), and Kelch-like ECH-associated protein 1 (Keap1) proteins in the prefrontal cortex of UCMS-exposed rats. Results: KGE treatment normalized UCMS-induced depression-related behaviors. Neurotransmitter studies conducted after completing behavioral experiments demonstrated that KGE caused a reduction in the ratio of serotonin and dopamine, indicating a decrease in serotonin and dopamine turnover. Moreover, the expression of BDNF, Nrf2, Keap1 and AKT were markedly increased by KGE in the prefrontal cortex of depressed rats. Conclusion: Our results provide evidence that KGE and its constituents exert antidepressant effects that mediate the dopaminergic and serotonergic systems and expression of BDNF protein in an animal model.

Win-Win Model Strategy According to Regulation on Large-Scale Stores (대형마트/SSM 출점 및 영업규제 대응에 따른 상생모델방안)

  • Park, Han-Hyuk
    • The Korean Journal of Franchise Management
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    • v.3 no.2
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    • pp.79-102
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    • 2012
  • The last year, the government restricted a new store open and businness hours of a large-scale stores, discount store and super super market(ssm). So, this research was examined the effect that the retailer was affected and its correspondence strategy First this research examined how the government restricted a large-scale stores in 2009 earlier and then this research analyzed how the Japan and France restricted it. Second this research examined that a new establishment and business hours change of a large-scale stores. Bacause of a small trader resistance in 2009 latter. Finally it analyzed the effect that a retail industry was affected in the future. bacause law was enforced. On the basis these things, a victim remedy was presented by retailers view. Bacause of international law and an excess regulation. Also, this research suggest that large retailer should expand a overse market and increase retailers private brand component ratio and develop overse brand. Finally this research also suggest that trader and retailer should continue to coperate and turn business direction into franchise system.

A Deep Optical Survey of Young Stars in the Carina Nebula. I. UBVRI Photometric Data and Fundamental Parameters

  • Hyeonoh Hur;Beomdu Lim;Moo-Young Chun
    • Journal of The Korean Astronomical Society
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    • v.56 no.1
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    • pp.97-115
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    • 2023
  • We present the deep homogeneous UBV RI photometric data of 135,071 stars down to V ~ 23 mag and I ~ 22 mag toward the Carina Nebula. These stars are cross-matched with those from the previous surveys in the X-ray, near-infrared, and mid-infrared wavelengths as well as the Gaia Early Data Release 3 (EDR3). This master catalog allows us to select reliable members and determine the fundamental parameters distance, size, stellar density of stellar clusters in this star-forming region. We revisit the reddening toward the nebula using the optical and the near-infrared colors of early-type stars. The foreground reddening [E(B-V)fg] is determined to be 0.35 ± 0.02, and it seems to follow the standard reddening law. On the other hand, the total-to-selective extinction ratio of the intracluster medium (RV,cl) decreases from the central region (Trumpler 14 and 16, RV,cl ~ 4.5) to the northern region (Trumpler 15, RV,cl ~ 3.4). It implies that the central region is more dusty than the northern region. We find that the distance modulus of the Carina Nebula to be 11.9 ± 0.3 mag (d = 2.4 ± 0.35 kpc) using a zero-age main-sequence fitting method, which is in good agreement with that derived from the Gaia EDR3 parallaxes. We also present the catalog of 3,331 pre-main-sequence (PMS) members and 14,974 PMS candidates down to V ~ 22 mag based on spectrophotometric properties of young stars at infrared, optical, and X-ray wavelengths. From the spatial distribution of PMS members and PMS candidates, we confirm that the member selection is very reliable down to faint stars. Our data will have a legacy value for follow-up studies with different scientific purposes.