• Wind and Structures
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• 제37권3호
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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.

• 한국항행학회논문지
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• 제27권4호
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• pp.463-468
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• 2023

본 논문에서는 Pin 다이오드와 결함접지구조를 이용하여 2 개의 편파(수직 편파, 우현 편파)를 전환하여 사용할 수 있는 이중편파 재구성 패치 배열 안테나를 제안한다. 제안된 안테나는 정사각형 마이크로스트립 패치와 접지면에 2개의 일자형 슬롯을 대각선으로 배치하여 구현된 원형 편파 패치 안테나를 5.8 GHz의 반파장 길이인 25.8 mm 간격으로 3x3 배열하여 설계하였으며 각 안테나의 접지면에 대각선으로 배치된 슬롯에 Pin 다이오드와 커패시터를 연결하여 Pin 다이오드에 직류 전압이 인가에 따른 개방/단락 스위치 동작을 통하여 편파를 전환한다. 설계 결과 수직 편파에서는 11.7 dBi, 우현 편파에서는 11.6 dBic의 이득 특성을 가지며 우현 편파에서의 축비는 1.8 dB, 수직 편파일 때 20.3 dB 를 가지고, 중앙 안테나에서 인접한 안테나의 상호결합 특성을 확인 하였을때 수직 편파에서는 최대 -20.8 dB, 우현 편파에서는 최대 -30.1 dB 이다.

• 한국항해항만학회지
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• 제47권4호
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• pp.239-245
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• 2023

본 연구는 지정학적 위기가 우리나라 항만 물동량에 미치는 영향에 대해서 분석하는 것을 목적으로 한다. 우리나라는 무역의존도가 높은 대외의존적인 경제구조를 가지고 있으며, 수출입의 대부분이 해상운송을 통해서 이루어지고 있다. 따라서, 지정학적 위기로 인하여 세계경제에 변동이 생기면 우리나라 항만 물동량에 영향을 미칠 수 있다는 이론적 예상이 가능하다. 이에 본 연구는 1995년~2022년 기간 동안 지정학적 위기가 우리나라 항만 물동량에 어떠한 영향을 미쳤는지를 분석하였다. 분석 결과, 지정학적 위기가 우리나라 항만 물동량에 미치는 영향은 일부 항만을 제외하고 통계적으로 유의하지 않는 것으로 나타났다. 그러나, 지정학적 위기가 항만물동량에 미치는 영향은 수출과 수입에 따라, 그리고 항만에 따라 다른 것으로 나타났다. 특히, 지정학적 위기는 수출 물동량에 부(-)의 영향을 미치는 것으로 나타났다. 또한, 항만을 통한 수출입 단가에 대해서 분석한 결과, 지정학적 위기는 수입단가에 부(-)의 영향을 미치는 것으로 나타났다.

• 대한의생명과학회지
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• 제29권1호
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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.

• International Journal of Computer Science & Network Security
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• 제23권1호
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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.

• Advances in environmental research
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• 제12권1호
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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.

• Current Optics and Photonics
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• 제7권1호
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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.

• Journal of Ginseng Research
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• 제47권4호
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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.

• 한국프랜차이즈경영연구
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• 제3권2호
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• pp.79-102
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• 2012

본 연구는 대형마트, 기업 형 슈퍼마켓 (SSM) 에 대한 출점 및 영업규제를 2009년 이전과 2009년 이후로 구분하여 연구하였다. 대형마트, 기업 형 슈퍼마켓 입장에서 영업 및 출점규제 법률시행에 따른 향후영향 및 대응 방안과 대안을 제시 하고자한다. 특히 2009년 이후 기업 형 슈퍼마켓의 출점 증가로 중소상인 보호를 위하여 유통법이 개정되어 출점과 영업규제 법률이 통과되고 조례제정을 통하여 규제가 현실화되었다. 이러한 법 개정이 외국사례와 국제법과 비교해서 그 타당성의 여부를 확인하고 향후방향을 제시했으며 실질적인 영세 상인임에도 오히려 과잉규제 대상이 된 프랜차이즈 슈퍼마켓 가맹점의 선의에 피해에 대한 법률적 구제방안도 제안하고자 한다. 본격적인 규제시행으로 유통업계는 해외진출 가속화, 유통업자 상표개발확대, 해외소싱상품 개발 등 경쟁력 강화를 위한 방안을 강구하고 중소상인과 대기업간의 상생모델인 프랜차이즈 가맹사업으로 사업방향을 전환하여 실질적인 상생협업모델을 추진하고 상생협력도 구축하면서 지속적인 성장을 추구해야한다.

• 천문학회지
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• 제56권1호
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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 (R_V,cl) decreases from the central region (Trumpler 14 and 16, R_V,cl ~ 4.5) to the northern region (Trumpler 15, R_V,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.