Efficiency Analysis of Port Companies in China Using DEA and the Malmquist Method

Wenjun He,Hye-Min Ma,Gi-Tae Yeo 한국항해항만학회 2017 한국항해항만학회지 Vol.41 No.5

The efficiency of port operations is an important indicator of port development. Moreover, there is excess handling capacity in Chinese ports, which results in a slower speed of development. Under the detrimental environment of the international shipping market, it is necessary to improve the operation efficiency of ports for long-term development. This paper provides an assessment of the competitiveness of Chinese seaport companies using the Boston Consulting Group’s matrix, and efficiency measurements using a data envelopment analysis and the Malmquist method. This analysis showed that highly efficient companies reformed their development strategies, which should be a solution considered by less efficient companies, such as Shenzhen Yan Tian Port Holdings Co., Ltd.. Although, having high throughput should be reformed in the investment structure. This research will assist port companies in gaining effective operating experience, and governments in establishing strategic planning to enhance the efficiency of port development.

Efficiency Analysis of Port Companies in China Using DEA and the Malmquist Method

He, Wenjun,Ma, Hye-Min,Yeo, Gi-Tae Korean Institute of Navigation and Port Research 2017 한국항해항만학회지 Vol.41 No.5

The efficiency of port operations is an important indicator of port development. Moreover, there is excess handling capacity in Chinese ports, which results in a slower speed of development. Under the detrimental environment of the international shipping market, it is necessary to improve the operation efficiency of ports for long-term development. This paper provides an assessment of the competitiveness of Chinese seaport companies using the Boston Consulting Group's matrix, and efficiency measurements using a data envelopment analysis and the Malmquist method. This analysis showed that highly efficient companies reformed their development strategies, which should be a solution considered by less efficient companies, such as Shenzhen Yan Tian Port Holdings Co., Ltd.. Although, having high throughput should be reformed in the investment structure. This research will assist port companies in gaining effective operating experience, and governments in establishing strategic planning to enhance the efficiency of port development.

Progranulin Controls Sepsis via C/EBPα-Regulated <i>Il10</i> Transcription and Ubiquitin Ligase/Proteasome-Mediated Protein Degradation

Yan, Wenjun,Ding, Aihao,Kim, Ha-Jeong,Zheng, Hua,Wei, Fang,Ma, Xiaojing American Association of Immunologists 2016 Journal of Immunology Vol. No.

<P>Progranulin (PGRN) is a widely expressed, pleiotropic protein that is involved in diverse biological processes, including cellular proliferation, neuron development, and wound healing. However, the role of PGRN in the regulation of pathogen-induced systemic inflammation and the mechanisms involved have not been established. In this study, we show that PGRN-deficient mice display heightened mortality in models of polymicrobial sepsis and endotoxinemia, with increased tissue levels of inflammatory cytokines and reduced IL-10 production. Conversely, administration of rPGRN decreases the susceptibility of PGRN-deficient mice to LPS-induced endotoxemic shock and augments IL-10 production by LPS-activated macrophages in a TNFR-dependent manner. Molecular analysis reveals a direct role of the transcription factor C/EBP alpha in PGRN-regulated IL-10 expression. C/EBP alpha-deficient macrophages produce less IL-10 in response to LPS. Furthermore, mice deficient in C/EBP alpha in hematopoietic cells are highly vulnerable to LPS-induced septic shock. Lastly, the defective IL-10 production by PGRN-deficient cells is primarily due to reduced C/EBP alpha protein stability via the E3 ubiquitin-conjugating enzyme E6AP and proteasome-mediated degradation. To our knowledge, this study provides the first evidence that PGRN is a nonredundant regulator of systemic inflammation via modulating the levels and activity of C/EBP alpha, IL-10, and the ubiquitin-proteasome proteolysis pathway. The results bear strong and profound implications for PGRN insufficiency and its mutation-associated systemic and organ-specific inflammatory human diseases.</P>

Quantifying carotid stiffness in a pre-hypertensive population with ultrafast ultrasound imaging

Xuehui Ma,Zhengqiu Zhu,Yinping Wang,Bixiao Shen,Xuezhong Jiang,Wenjun Liu,Yiyun Wu,Chong Zou,Yun Luan,Hui Gao,Hui Huang 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.1

Purpose: The aim of this study was to assess carotid stiffening in a pre-hypertensive (PHT) population using ultrafast pulse wave velocity (ufPWV). Methods: This study retrospectively enrolled 626 individuals who underwent clinical interviews, serum tests, and assessments of the systolic blood pressure (SBP), diastolic blood pressure (DBP), carotid intima-media thickness (cIMT), pulse wave velocity-beginning of systole (PWV-BS), and pulse wave velocity-end of systole (PWV-ES) between January 2017 and December 2021. The patients were divided into three groups according to their blood pressure (BP)—normal BP (NBP): SBP <130 mmHg and DBP <80 mmHg (n=215); PHT: 130 mmHg≤SBP<140 mmHg and/or 80 mmHg≤DBP<90 mmHg (n=119); hypertensive (HT): SBP ≥140 mmHg and/or DBP ≥90 mmHg (n=292). Correlation analyses and comparisons were performed among the groups and in the cIMT subgroups (cIMT ≥0.050 cm and <0.050 cm). Results: cIMT and PWV-ES significantly differed among the BP groups (P<0.05). The BP groups had similar PWV-BS when cIMT <0.050 cm or cIMT ≥0.050 cm (all P>0.05). However, the NBP group had a notably lower PWV-ES than the PHT (P<0.001 and P=0.024) and HT (all P<0.001) groups in both cIMT categories, while the PWV-ES in the PHT group were not significantly lower than in the HT group (all P>0.05). Conclusion: Carotid morphological and biomechanical properties in the PHT group differed from those in the NBP group. ufPWV could be used for an early evaluation of carotid stiffening linked to pre-hypertension.

Inhibiting oxidation and enhancing absorption characteristics of sodium sulfite for SO₂ removal from the non-ferrous smelting flue gas

Yongpeng Ma,Dongli Yuan,Xiaojing Zhang,Zan Qu,Wenjun Huang 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.2

In this work, we investigated the absorption characteristics of SO₂ and the effect of inhibitors on the desulfurization performances of Na₂SO₃. The results showed that the NO₂ had a competitive effect with SO₂ on SO₃<SUP>2-</SUP> which resulted in a significant decrease in the absorption capacity of SO₂. O₂ in the flue gas could decrease the absorption capacity of SO₂ due to the oxidation of Na₂SO₃. Besides, Na₂S₂O₃ had more excellent inhibiting effect on the oxidation of SO₃<SUP>2-</SUP>; the inhibition mechanism is understood on the basis of the free radical chain reaction, whereby S₂O₃<SUP>2-</SUP> combined with the sulfite free radical to form an inert substance, thus, quenching the reaction of free radical with the dissolved oxygen and invariably inhibiting the oxidation of SO₃<SUP>2-</SUP>. Furthermore, the intrinsic and the apparent oxidation kinetics of Na₂SO₃ oxidation process with Na₂S₂O₃ were investigated to explain the relationships between consumption rates of SO₃<SUP>2-</SUP> and the absorption capacities of SO₂ under different components in flue gas and absorption solution.

A Flattop Radiation Pattern Antenna with Special‑Shaped Array Placement for Stadium Communications

Bing Ma,Tao Zhang,Wenjun Gao,Xiaotian Wang,Zhijia Liu 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

A fattop radiation pattern antenna with special-shaped array placement for large-scale stadium communications is presented in this paper. The antenna array consists of only 16 electric dipoles, each of that is±45° linear polarizations, placed in three rings confguration above a ground plane. Under the ground plane two feeding networks with±45° linear polarizations, respectively are used to divide signals to the 16 electric dipoles to produce fattop radiation patterns. A prototype operated at 2300–2700 MHz for stadium wireless communications, such as 4G LTE, is manufactured and tested, and good agreements between simulation and measurement are demonstrated. The measured gain is above 12 dBi and the side-lobe levels are lower than −20 dB. The measured isolations between the two polarization ports are less than −30 dB within the operating band. A fast beam ramp of less than 20° from −3 to −20 dB is achieved.

Riemann hypothesis for period polynomials of modular forms

Jin, Seokho,Ma, Wenjun,Ono, Ken,Soundararajan, Kannan National Academy of Sciences 2016 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.113 No.10

<P>The period polynomial r(f) (z) for an even weight k >= 4 newform f epsilon S-k(Gamma(0)(N)) is the generating function for the critical values of L(f, s). It has a functional equation relating r(f) (z) to r(f) (-1/Nz). We prove the Riemann hypothesis for these polynomials: that the zeros of r(f) (z) lie on the circle vertical bar z vertical bar = 1 / root N . We prove that these zeros are equidistributed when either k or N is large.</P>

Effects of resveratrol on the inflammatory response and renal injury in hyperuricemic rats

Xiao Benxi,Ma Wenjun,Zheng Ying,Li Zhen,Li Dan,Zhang Yanjun,Li Yuanhong,Wang Duan 한국영양학회 2021 Nutrition Research and Practice Vol.15 No.1

BACKGROUND/OBJECTIVES: Hyperuricemic nephropathy is a common cause of acute kidney injury. Resveratrol can ameliorate kidney injury, but the explicit mechanism remains unclear. We investigated the effects of resveratrol on the inflammatory response and renal injury in hyperuricemic rats. MATERIALS/METHODS: A rat model of hyperuricemic nephropathy was established by the oral administration of a mixture of adenine and potassium oxinate. Biochemical analysis and hematoxylin and eosin staining were performed to assess the rat kidney function. Enzyme-linked immunosorbent assays were performed to evaluate the immune and oxidative responses. RESULTS: The expression levels of urine albumin and β2-microglobulin were significantly decreased after resveratrol treatment. In addition, the levels of serum creatinine and uric acid were significantly decreased in the resveratrol groups, compared with the control group. The levels of proinflammatory factors, such as interleukin-1β and tumor necrosis factor-α, in kidney tissue and serum were also increased in the hyperuricemic rats, and resveratrol treatment inhibited their expression. Moreover, the total antioxidant capacity in kidney tissue as well as the superoxide dismutase and xanthine oxidase levels in serum were all decreased by resveratrol treatment. CONCLUSIONS: Resveratrol may protect against hyperuricemic nephropathy through regulating the inflammatory response.

Preparation of Copper Nanoparticles and Catalytic Properties for the Reduction of Aromatic Nitro Compounds

Duan, Zhongyu,Ma, Guoli,Zhang, Wenjun Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

A novel copper nanoparticles were synthesized from cupric sulfate using hydrazine as reducing reagents. A series of aromatic nitro compounds were reacted with sodium borohydride in the presence of the copper nanoparticles catalysts to afford the aromatic amino compounds in high yields. Additionally, the catalysts system can be recycled and maintain a high catalytic effect in the reduction of aromatic nitro compounds.

Paleoenvironmental changes of source rocks from the Carboniferous to Permian sediments of the Mahu Sag, Junggar Basin, China

Feng Chong,Ma Mingze,He Wenjun,Li Teng,Wu Qiuyu,Zhang Zexin,Zhao Haiyang 한국자원공학회 2020 Geosystem engineering Vol.23 No.5

There are four sets of source rocks from Carboniferous (C) to Permian in Mahu Sag, and the paleoenvironment is the decisive factor for the differences of source rocks. In order to study the controlling effect of paleoenvironmental evolution on the change of source rock properties, the major, trace elements and the total organic carbon (TOC) of 47 core samples from four sets of source rocks were tested. The results indicate that the paleoenvironmental evolution of these four sets of source rocks from C to Permian in Mahu Sag can be divided into five stages. At the end of C and the early stage of deposition of Wuerhe formation (P2w), the paleo climate became warm and humid, and the salinity of water body became small. Meanwhile, the oxidizability of water body gradually became stronger. At the deposition stage of Jiamuhe Formation (P1j), Fengcheng Formation (P1f) and the late stage of deposition of P2w, the paleo climate gradually became hot and dry, and the salinity of water body gradually increased. Meanwhile, the reducibility of water body became stronger. The paleoenvironmental factors controlling the abundance of organic matter in source rocks are different in different stages.