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Time-of-use price is an important means of demand side management, how to accurately divide peak and valley periods is an important problem to be solved. In this paper, an improved fuzzy c-means (FCM) clustering algorithm is proposed to solve the problem that traditional FCM clustering algorithm is sensitive to the initial clustering center and easy to fall into local optimal. This algorithm combines an improved particle swarm optimization (PSO) based on support vector machine regression (SVR) with FCM algorithm, makes full use of the strong global search ability of PSO, replaces FCM to find the clustering center at the beginning of iteration, makes it out of the local optimal, realizes fuzzy clustering, and thus classifies more accurate peak and valley periods. Finally, the improved algorithm is applied to an example of an industrial park, and a distributed energy storage system is set up. The effectiveness of the proposed method is verified by simulation.

Background: The study aimed to examine the antipsychotic treatment effect on the serum S100B and oxidative stress in patients with schizophrenia. Methods: Subjects consisted of patients with schizophrenia of first-episode drug-naive and drug-free acute phases, and met the DSM-IV diagnostic criteria for schizophrenia. All patients were treated with risperidone for eight weeks. Positive and Negative Syndrome Scale (PANSS) was evaluated, and serum levels of S100B and parameters of oxidative stress including total oxidative status (TOS) and malondialdehyde (MDA) were measured before and after antipsychotic treatment. A general linear random-effect model was used for data analysis. Results: Antipsychotic treatment with risperidone reduced the levels of S100B significantly in the first episode drug-naive patients with schizophrenia (Beta=24.89; p=0.0087) and marginally in the drug-free acute phase (Beta=15.65; p=0.093), no significant difference in the effect on S100B between patient groups (p=0.4785). In contrast, antipsychotic treatment increased the levels of MDA in drug-free acute phase schizophrenia (Beta=-6.55; p

Background: Patients with schizophrenia have been noted with an elevation of serum S100B protein concentration, but the pathological process is not known. This study was to investigate the relationship between levels of S100B protein and oxidative stress. Methods: General information and blood sample were collected from the first-episode drug naïve or drug-free acute stage of patients who met the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria for schizophrenia and healthy controls. The serum levels of S100B, total oxidants (TOS) and malonaldehyde (MDA) were used to measure the level of oxidative stress in both patients, and healthy controls. General linear regression analysis was performed to examine the association of S100B protein with the levels of oxidative stress. Results: The levels of serum protein S100B were associated with the concentration of both TOS (Beta=15.77; p=0.0038) and MDA (Beta=7.90; p=0.0068) in the first-episode drug-naive patients (n=29).While both associations were no longer significant (p>0.05) in the drug-free acute phase patients (n=29); the levels of serum S100B was still consistently associated with TOS (Beta=12.42;p=0.0026) and MDA(Beta=4.11;p=0.0480) in the combined group of patients group(n=58). Simultaneous analysis of both oxidative markers, we still found that both TOS (Beta=12.88; p=0.0103) and MDA (Beta=6.46; p=0.0167) were associated with the serum level of protein S100B in the first-episode drug-naive patients, but not drug-free acute phase patients. Conclusion: Our results suggest that astrocyte activity, serum levels of oxidants, and their cross-talking might be involved in the pathogenesis of schizophrenia. This warrants a further study for understanding the underlying mechanism.

Background This study integrates data from high-quality mental health surveys in five provinces in China to examine the prevalence, demographic correlates, age of onset, and comorbidity of alcohol use disorder (AUD). Methods The five cross-sectional surveys initially screened a representative sample of 74,752 community-living adults (94% response rate) from a sampling population including over 12% of China’s adult population. Psychiatrists then administered a detailed diagnostic exam to an enriched sample of 21,015 respondents (95% response rate). The prevalence of AUD in females in China is below 0.5%, so we limited our analysis to 9619 males who completed the diagnostic interview. Results Using meta -analyses to summarize estimates across the five locations, the current (30-day) prevalence of AUD among adult Chinese males was 9.8% (95% CI = 5.7–16.9%), but there was wide cross-province variation. After adjusting for age and other demographic variables, the prevalence of AUD was significantly lower in single men than in married men (OR = 0.4, CI = 0.2–0.7), lower in men who were not currently working than in men who were currently working (OR = 0.7, CI = 0.5–0.96), and lower in men with comorbid mental disorders than in men without comorbid mental disorders (OR = 0.4, CI = 0.2–0.8). The risk of developing AUD peaked at 30 years of age. Conclusions Substantial differences in the demographic correlates and age of onset of AUD in men in China compared to those reported in other countries highlight the importance of understanding the country-specific and region-specific profile of AUD before developing intervention and prevention strategies.

In this paper, we present a system to detect and count the number of vehicles in traffic surveillance videos based on Fast Region-based Convolutional Network (Fast R-CNN). Fast R-CNN is a state-of-the-art object detection network, which takes an entire image and a set of object proposals as input, produces bounding-box positions with probability estimates over object classes as output. First, we fine-tune a pre-trained Fast R-CNN net with images captured from traffic videos for accuracy improvement. Second, we define a series of rules of bounding boxes screening for vehicle counting. The proposed system takes around 3 seconds per image to count vehicles on a GTX970 GPU, and then records the corresponding number of vehicles into a database for traffic flow analysis. Experimental results demonstrated that the proposed system can provide significant improvements on the detection accuracy. In addition, experiments on challenging videos with occlusions or full of vehicles show that the proposed system works effectively.

Background Suicide intervention programs have been guided by findings that attitude towards suicide and suicidal behavior may be causally linked. These findings also make it imperative to identify the factors that influence attitudes towards suicide. However, there has been little research on attitudes towards suicide among the general population, especially in low-income and middle-income countries. This population-based, cross-sectional study investigated the associated factors of attitudes towards suicide among a representative sample of urban and rural adult residents in China. Methods A multi-stage, stratified random sampling approach was implemented to select participants. Data were collected by a survey using the Scale of Public Attitudes about Suicide (SPAS). The survey also collected some socio-demographic factors and suicidal history of participants. Statistical tests were conducted to identify associated factors that account for variations in attitudes towards suicide. Results The residents in China generally hold a neutral attitude towards suicide. Attitudes towards suicide among Chinese residents were associated with age, duration of formal education, marital status, job and suicidal ideation. Different attitudinal subscales seemed not to share the same risk factors. However, gender, ethnicity, religious belief, housing style and economic status might not influence residents’ attitudes towards suicide. Attitudes towards suicide among Chinese urban and rural residents generally had no statistical difference with one notable exception: opinions on whether or not suicides and suicide attempts are different phenomena. Conclusions Age, duration of formal education, marital status, job and suicidal ideation seem to have an impact on attitudes towards suicide among residents. Urban and rural residents have similar attitudes towards suicide with the only statistically significance difference being their opinions on whether or not suicides and suicide attempts are different phenomena. Electronic supplementary material The online version of this article (doi:10.1186/s12888-016-0872-z) contains supplementary material, which is available to authorized users.

Summary Background In China and other middle-income countries, neuropsychiatric conditions are the most important cause of ill health in men and women, but efforts to scale up mental health services have been hampered by the absence of high-quality, country-specific data for the prevalence, treatment, and associated disability of different types of mental disorders. We therefore estimated these variables from a series of epidemiological studies that were done in four provinces in China. Methods We used multistage stratified random sampling methods to identify 96 urban and 267 rural primary sampling sites in four provinces of China; the sampling frame of 113 million individuals aged 18 years or older included 12% of the adult population in China. 63 004 individuals, identified with simple random selection methods at the sampling sites, were screened with an expanded version of the General Health Questionnaire and 16 577 were administered a Chinese version of the Structured Clinical Interview for Diagnostic and Statistical Manual (DSM)-IV axis I disorders by a psychiatrist. Findings The adjusted 1-month prevalence of any mental disorder was 17·5% (95% CI 16·6–18·5). The prevalence of mood disorders was 6·1% (5·7–6·6), anxiety disorders was 5·6% (5·0–6·3), substance abuse disorders was 5·9% (5·3–6·5), and psychotic disorders was 1·0% (0·8–1·1). Mood disorders and anxiety disorders were more prevalent in women than in men, and in individuals 40 years and older than in those younger than 40 years. Alcohol use disorders were 48 times more prevalent in men than in women. Rural residents were more likely to have depressive disorders and alcohol dependence than were urban residents. Among individuals with a diagnosable mental illness, 24% were moderately or severely disabled by their illness, 8% had ever sought professional help, and 5% had ever seen a mental health professional. Interpretation Substantial differences between our results and prevalence, disability, and treatment rate estimates used in the analysis of global burden of disease for China draw attention to the need for low-income and middle-income countries to do detailed, country-specific situation analyses before they scale up mental health services. Funding China Medical Board of New York, WHO, and Shandong Provincial Bureau of Health.

Since suicide in Chinese people exhibits certain distinctive characteristics, it is important to develop indigenous measures to assess Chinese attitudes toward suicide that may be used to inform suicide reduction programs. Combining qualitative and quantitative methods, we developed a Hong Kong version of the Chinese Attitude toward Suicide Questionnaire (CASQ-HK) which assesses attitudes toward suicide, suicidal inclination under 12 hypothetical scenarios, and prior suicidal experience. A convenience sample of 1,226 people completed the self-report questionnaire. In keeping with Chinese tradition, respondents revealed both tolerant and condemning attitudes that varied with their sociodemographic characteristics. Generally, they were not strongly inclined to consider suicide in the presence of difficult scenarios. Female gender, older age, and the presence of suicidal ideation were associated with more contemplation of suicide.

This paper proposed the drawback of Doubly Fed Induction Generator (DFIG) during voltage drops. Since the stator winding of DFIG is directly connected to the grid, DFIG is sensitive to the grid fault, especially to voltage drops. With the increasing capacity of wind turbines, the wind turbines need to meet the certain ability to across low voltage. The research of dynamic behavior based on DFIG during voltage drops is important to provide the evidence to protecting circuit. Due to the electromagnetic transient process of DFIG, this paper analyzed the analytical expressions of stator current? rotor current and the dc bus voltage both in symmetrical short-circuit and asymmetric short-circuit. The simulation results in PSCAD/EMTDC proved the correctness of the theoretical expression.

The Voltage Source Converter-HVDC (VSC-HVDC) system applied to wind power generation can solve large scale wind farm grid-connection and long distance transmission problems. However, the low voltage ride through (LVRT) of the VSC-HVDC connected wind farm is a key technology issue that must be solved, and it is currently lacking an economic and effective solution. In this paper, a LVRT coordinated control strategy is proposed for the VSC-HVDC-based wind power system. In this strategy, the operation and control of VSC-HVDC and wind farm during the grid fault period is improved. The VSC-HVDC system not only provides reactive power support to the grid, but also effectively maintains the power balance and DC voltage stability by reducing wind-farm power output, without increasing the equipment investment. Correspondingly, to eliminate the influence on permanent magnet synchronous generator (PMSG)-based wind turbine (WT) systems, a hierarchical control strategy is designed. The speed and validity of the proposed LVRT coordinated control strategy and hierarchical control strategy were verified by MATLAB/Simulink simulations.

This paper proposes a low-voltage ride-through (LVRT) protection scheme without fault current limiter (FCL) on the grid-side inverter (GSI), based on energy balance characteristics of permanent magnet synchronous generator (PMSG) wind power systems during the grid voltage drop. The scheme utilizes a series dynamic braking resistor (SDBR) to consume the excess active power from the PMSG transmitting to the grid during the voltage drop. A detailed design procedure and control strategy for the SDBR is presented. The theoretical analysis and the PSCAD/EMTDC simulation results prove that the proposed protection scheme can boost GSI voltage, limit GSI over-current, stabilize DC-link voltage, guarantee the safe and stable operation of the converters, and then improve LVRT capability of PMSG wind power system.

A desired islanding detection method applied in microgrid not only can detect islanding correctly within acceptable duration as same as that in distributed generation system, but also ensures the smooth transition from grid-connected mode to islanded mode. In the paper an islanding detection method is presented, which considers the characteristics of system equivalent impedance that varies with the microgrid connecting main grid or not, with the help of the negative current injection into the point of common coupling (PCC), and then identifies the negative voltage variations near PCC. The method is able to avoid the negative impact on the operation stability of the microgrid. Through the Matlab/Simulink simulation, the rapidity and affectivity of these principles are verified.

HVDC Light is a new generation of HVDC power transmission based on PWM controlled voltage source converter(VSC). First, this paper presents an equivalent statespace model of HVDC Light system under dq synchronous rotating coordinate system. After established the detailed model, the simplified model based on the multi-time scale theory was given. The HVDC Light mathematical model is decomposed into the slow and fast subsystems in explicit form. By applying state-feedback, output feedback control strategy based on multi-time scale model is proposed. In the end, the coherency between the reduced and composite models is compared by MATLAB simulation, and the simulation result assures that the simplified model based on multi-time scale is valid to design state-feedback controller.

BackgroundSuicide is the most common cause of death among youth in China.MethodA case-control psychological autopsy study in 23 geographically representative disease surveillance points around China collected information from family members and close associates of 114 persons aged 15–24 years who died by suicide (cases) and 91 who died of other injuries (controls).ResultsAmong the 114 suicides 61% were female, 88% lived in rural villages, 70% died by ingesting pesticides (most commonly stored in the home), 24% previously attempted suicide, and 45% met criteria of a mental illness at the time of death. Multivariate logistic regression identified several independent risk factors: severe life events within 2 days before death (OR 31.8, 95% CI 2.6–390.6), presence of any depressive symptoms within 2 weeks of death (OR 21.1, 95% CI 4.6–97.2), low quality of life in the month before death (OR 9.7, 95% CI 2.8–34.1), and acute stress at time of death (moderate: OR 3.1, 95% CI 0.8–11.9; high: OR 9.1, 95% CI 1.2–66.8). A significant interaction between mental illness at time of death and gender indicated that diagnosis was an important predictor of suicide in males (OR 14.0, 95% CI 2.6–76.5) but not in females (OR 0.3, 95% CI 0.0–3.6). Prior suicide attempt was related to suicide in the univariate analysis (OR 57.5) but could not be included in the multivariate model because no controls had made prior attempts.ConclusionsSuicide prevention efforts for youth in China must focus on restricting access to pesticides, early recognition and management of depressive symptoms and mental illnesses, improving resiliency, and enhancing quality of life.

Background Attitudes and knowledge about suicide may influence psychiatrists’ management of suicidal patients but there has been little research about this issue in China. Methods We used the Scale of Public Attitudes about Suicide (SPAS) – a 47-item scale developed and validated in China – to assess knowledge about suicide and seven specific attitudes about suicide in a sample of 187 psychiatrists from six psychiatric hospitals in Shanghai. The results were compared to those of 548 urban community members (assessed in a previous study). Results Compared to urban community members, psychiatrists were more likely to believe that suicide can be prevented and that suicide is an important social problem but they had more stigmatizing beliefs about suicidal individuals and felt less empathy for them. The belief that suicide can be prevented was more common among female psychiatrists than male psychiatrists but male psychiatrists felt more empathy for suicidal individuals. Only 37% of the psychiatrists correctly agreed that talking about suicide-related issues with an individual would not precipitate suicidal behavior and only 41% correctly agreed that those who state that they intend to kill themselves may actually do so. Conclusions Many psychiatrists in Shanghai harbor negative attitudes about suicidal individuals and are concerned that directly addressing the issue with patients will increase the risk of suicide. Demographic factors, educational status and work experience are associated with psychiatrists’ attitudes about suicide and, thus, need to be considered when training psychiatrists about suicide prevention.