Irreversible Investment under Uncertainty and Competition: Evidence from Patent Examination Requests in Korea

( Zhen Lei ),( Jun Byoung Oh ) 한국산업조직학회 2014 한국산업조직학회 정책세미나 논문집 Vol.2014 No.3

Filing patent application and examination request under deferred patent examination system provides inventor with option value and similar decision process on the irreversible investment under uncertainty and competition. This paper investigates firm decisions on whether and when to request patent examinations under a deferred patent examination system in Korea, and provides the first empirical evidences on how firms, faced with both uncertainty about investment return and market competition, make decision on its irreversible investment. We provide a simple theoretical model and show that both uncertainty in invention value and market competition has significant impact on firm’s examination requests in particular for less valued inventions, and the negative correlation between uncertainty and competition leads to the interesting bipolar distribution.

Irreversible Investment under Uncertainty and Competition: Evidence from Patent Examination Requests in Korea

( Zhen Lei ),( Jun Byoung Oh ) 한국산업조직학회 2014 한국산업조직학회 정책세미나 논문집 Vol.2014 No.2

Filing patent application and examination request under deferred patent examination system provides inventor with option value and similar decision process on the irreversible investment under uncertainty and competition. This paper investigates firm decisions on whether and when to request patent examinations under a deferred patent examination system in Korea, and provides the first empirical evidences on how firms, faced with both uncertainty about investment return and market competition, make decision on its irreversible investment. We provide a simple theoretical model and show that both uncertainty in invention value and market competition has significant impact on firm’s examination requests in particular for less valued inventions, and the negative correlation between uncertainty and competition leads to the interesting bipolar distribution.

Coupled Discriminant Analysis for Heterogeneous Face Recognition

Zhen Lei,Shengcai Liao,Jain, A. K.,Li, S. Z. IEEE 2012 IEEE transactions on information forensics and sec Vol.7 No.6

<P>Coupled space learning is an effective framework for heterogeneous face recognition. In this paper, we propose a novel coupled discriminant analysis method to improve the heterogeneous face recognition performance. There are two main advantages of the proposed method. First, all samples from different modalities are used to represent the coupled projections, so that sufficient discriminative information could be extracted. Second, the locality information in kernel space is incorporated into the coupled discriminant analysis as a constraint to improve the generalization ability. In particular, two implementations of locality constraint in kernel space (LCKS)-based coupled discriminant analysis methods, namely LCKS-coupled discriminant analysis (LCKS-CDA) and LCKS-coupled spectral regression (LCKS-CSR), are presented. Extensive experiments on three cases of heterogeneous face matching (high versus low image resolution, digital photo versus video image, and visible light versus near infrared) validate the efficacy of the proposed method.</P>

Effects of L-lysine on thermal gelation properties of chicken breast actomyosin

Zhen Lei,Yuan Fu,Yadong Zheng,Peng Xu,Cunliu Zhou 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

The effects of L-lysine (L-Lys) on the water holding capacity (WHC) and texture of actomyosin (AM) gel and the possible mechanisms were investigated. L-Lys increased the WHC and hardness of the AM gel. These effects may be related to the even and continuous microstructure of the gel according to the scanning electron microscopy analysis. Furthermore, L-Lys increased the surface hydrophobic residues and the reactive sulfhydryl groups. L-Lys decreased the storage modulus at the first transition temperature but increased it at the second transition temperature and the third transition enthalpy. These results suggested that L-Lys varied the thermal behaviors and the microstructure of the AM gel by increasing the surface hydrophobicity and reactive sulfhydryl groups, ultimately contributing to the increased WHC and hardness. The changes in pH did not fully explain the results from the present study. The results were useful for understanding previous findings and may serve as a reference for the preparation of reduced-sodium and phosphate-free meat products.

Rockburst occurrences and microseismicity in a longwall panel experiencing frequent rock bursts

Zhen-lei Li,Xue-qiu He,Lin-ming Dou,Gui-feng Wang 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.4

A rockburst is a kind of dynamic geological hazard faced by engineers and researchers. Identification of a potential rockburst risk area (PRBRA) allows effective, targeted measures to be taken mitigate these hazards. To provide a reference for determining PRBRA in longwall panels with similar conditions, an in situ investigation that lasted for over three years was conducted on LW3401 in the Junde coal mine which experienced a total of 22 rockbursts. The investigation involves rockburst consequences (including the location, length, degree, and modes of the ensuing damage), seismic features of rockburst (including the source and seismic energy), and the relationship between rockbursts and microseismicity. Results show that damaged areas are mostly within the 18 m behind the excavation face, or up to 30 m ahead of the coalface. Lengths of damaged sections of roadways are within 95 m (and 115 m) during roadway excavation (and coalface advancing operations). The seismic energy of rockbursts ranges from 1.60 × 104 to 8.21 × 106 J. Sources of rockbursts lie mostly within 145 m of damage locations. Before a rockburst, sources of microseismic (MS) events begin to cluster around the roadway or coalface. Daily total energy and MS event counts rose, then fell, before a rockburst occurred. PRBRAs in a roadway lie within a certain distance behind the excavation face, or ahead of the coalface. When high-energy MS events are found in close proximity to a PRBRA, the rockburst risk in a given panel increases.

Real-time hydrogen mud logging during the Wenchuan earthquake fault scientific drilling project (WFSD), holes 2 and 3 in SW China

Zhen Fang,Yaowei Liu,Duoxing Yang,Lishuang Guo,Lei Zhang 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.3

We present hydrogen gas concentration data for drilling mud extracted during the Wenchuan Earthquake Fault Scientific Drilling (WFSD; holes 2 and 3), measured on-line during drilling in SW China. Hydrogen influx into the well at depth is largely dependent on lithology and fracture density. In hole WFSD-2, the average background concentration of hydrogen is lower in granitic rocks than in sedimentary formations. More than five major hydrogen influxes were detected while drilling through the sedimentary formations, and two hydrogen-rich zones were detected in the granite (1240–1243 m and 1383.5–1405 m depth). In hole WFSD-3, mud extracted from a tectonic breccia contains high hydrogen concentrations at depths of 600–1000 m depth, and relatively low concentrations below 1000 m depth. In both holes, we observe a lack of hydrogen in the center of the fault zone and high concentrations of hydrogen in fractured zones. Hydrogen concentration in both holes displays significant vertical heterogeneity, and is positively correlated with fracture density. Hydrogen was likely sourced from interaction between water and fresh silicate minerals surfaces that were exposed during faulting, from the mantle, and from faulting events. Fracture zones provide the main channels for the migration of hydrogen gas. The variations in background hydrogen concentrations relate to changes in porosity and permeability. The two hydrogen-rich zones (642.36–676.22 m, and 1383.5–1405 m) were likely caused by earthquake activity or far-field triggering during WFSD-2 drilling. The results of this study provide gas data that can be used to model fault activity. It is important to consider the relationship between hydrogen gas and the seismic cycle, and to use such data to identify seismic precursors.

Upregulation and biological function of transmembrane protein 119 in osteosarcoma

Zhen-Huan Jiang,Jun Peng,Hui-Lin Yang,Xing-Li Fu,Jin-Zhi Wang,Lei Liu,Jian-Nong Jiang,Yong-Fei Tan,Zhi-Jun Ge 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Osteosarcoma is suggested to be caused by genetic and molecular alterations that disrupt osteoblast differentiation. Recent studies have reported that transmembrane protein 119 (TMEM119) contributes to osteoblast differentiation and bone development. However, the level of TMEM119 expression and its roles in osteosarcoma have not yet been elucidated. In the present study, TMEM119 mRNA and protein expression was found to be up-regulated in osteosarcoma compared with normal bone cyst tissues. The level of TMEM119 protein expression was strongly associated with tumor size, clinical stage, distant metastasis and overall survival time. Moreover, gene set enrichment analysis (GSEA) of the Gene Expression Omnibus (GEO) GSE42352 dataset revealed TMEM119 expression in osteosarcoma tissues to be positively correlated with cell cycle, apoptosis, metastasis and TGF-β signaling. We then knocked down TMEM119 expression in U2OS and MG63 cells using small interfering RNA, which revealed that downregulation of TMEM119 could inhibit the proliferation of osteosarcoma cells by inducing cell cycle arrest in G0/G1 phase and apoptosis. We also found that TMEM119 knockdown significantly inhibited cell migration and invasion, and decreased the expression of TGF-β pathway-related factors (BMP2, BMP7 and TGF-β). TGF-β application rescued the inhibitory effects of TMEM119 knockdown on osteosarcoma cell migration and invasion. Further in vitro experiments with a TGF-β inhibitor (SB431542) or BMP inhibitor (dorsomorphin) suggested that TMEM119 significantly promotes cell migration and invasion, partly through TGF-β/BMP signaling. In conclusion, our data support the notion that TMEM119 contributes to the proliferation, migration and invasion of osteosarcoma cells, and functions as an oncogene in osteosarcoma.

A 3-D Steady-State Analysis of Thermal Behavior in EHV GIS Busbar

Lei, Jin,Zhong, Jian-ying,Wu, Shi-jin,Wang, Zhen,Guo, Yu-jing,Qin, Xin-yan The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

Wind tunnel study of wind structure at a mountainous bridge location

Lei Yan,Zhen S. Guo,Le D. Zhu,Richard G. J. Flay 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.23 No.3

Wind tunnel tests of a 1/2200-scale mountainous terrain model have been carried out to investigate local wind characteristics at a bridge location in southeast Tibet, China. Flows at five key locations on the bridge at deck level were measured for 26 directions. It was observed that wind characteristics (including mean wind velocity and overall turbulence intensity) vary significantly depending on the approaching wind direction and measurement position. The wind inclination angle measured in the study fluctuated between -18 and +16 and the ratio of mean wind velocity to reference wind velocity was small when the wind inclination angles were large, especially for positive wind inclination angles. The design standard wind speed and the minimum critical wind speed for flutter rely on the wind inclination angle and should be determined from the results of such tests. The variation of wind speed with wind inclination angles should be of the asymmetry step type. The turbulence characteristics of the wind were found to be similar to real atmospheric flows.

Pole-to-Ground Fault Analysis for MMC-HVDC Grid

Zhen He,Jiabing Hu,Lei Lin,Zhiyuan He 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Pole-to-ground (PTG) fault analysis is of vital importance for HVDC grid. However, many factors are not considered in the existing studies, such as the asymmetrical property of PTG fault, the coupling issue between dc transmission lines and the complexity of dc grid’s structure. This paper presents a PTG fault analysis method, which is based on common- and differential-mode (CDM) transformation. Similar to the symmetrical component method in ac system, the transformation decomposes the HVDC grid into CDM networks at first. Then, under the perspective of CDM components, a transfer impedance based analysis is performed to obtain the analytical expressions of PTG fault characteristics. The proposed PTG fault analysis method is applicable to arbitrary HVDC grid topologies. And the analytical expressions can give theoretical guidance for fault protection. The validity of the proposed PTG fault analysis method is verified by comparison with the simulation results in PSCAD/EMTDC.