درخت حوزه‌های تخصصی

Value stream mapping because of being able to understand process bottlenecks, as one of the most common tools for analyzing, identifying and eliminating various losses in operational and support processes are used. On the other hand, inventory management, precise control entry and exit of goods, accurate and timely information about the inventories status and planning, reduce product maintenance costs, including important issues organizations have a special look to it to consider the whole objectives and strategies, making procedures and policies that have a positive effect on the overall organization’s economy. In this paper, the use of value stream mapping as a lean production technique, in a production process to improve inventory control is discussed. This is a tool seeks to reduce losses, especially losses related to inventory by mining a bearing manufacturer companies. In this study, the literature of value stream mapping considered. The current state and future state of the company drawn in order to improve production process and losses in the company's future status. In addition, after drawing the mapping, the results of the simulation software Arena and the final report suggests that the use of this technique has an impact on reduce losses and increase inventory turnover.

The aim of this study is to investigate the relationship between social capital among employees with their job performance in Tehran's Forensic Medicine Organization. The study population consisted of all the employees of Tehran's Forensic Medicine Organization in 2015 that based on available statistics are 120 employees that because of limited statistical population, sampling has not been done. To collect data, two instruments were used to measure including social capital questionnaire of Nahapiet and Ghoshal (1998), with average reliability coefficient of 93% and job performance questionnaire of Hersey and Goldsmith Achiu model with average reliability coefficient of 88%. Descriptive statistics were used to describe the data and to analyze and evaluate the research hypotheses; test of inferential statistics including univariate regression analysis was used. While confirming the research hypotheses, results showed: Structural, cognitive and communicative dimensions of social capital of employees have an increasing and positive impact on their job performance and this effect is statistically significant.

The Internet along with many advantages has some disadvantages, and the lack of a complete understanding of cyberspace can cause damage in terms of mate selection method. This article attempts to address some of the disadvantages and threats that virtual spaces create in mate selection method and tries to introduce some strategies to prevent and reduce these emerging injuries. This study was conducted using a questionnaire survey and the reference method. The population of this research is all youth between 20 to 34 years old who live in Jahrom in 1395. The sampling methods used here is the cluster sampling method. The sample size has been calculated by the Cochran formula, and 320 people were selected. The questionnaire was 0.77 alpha general questionnaire and statistical analysis was performed by SPSS software in the form of analyzing the correlation coefficient and regression. In this research, after describing the stages of major indicators of family position as the most important unit of society, and after declaring the ideas about mate selection and cyberspace relationships, and mentioning them as opportunities and threats, emerging injuries following by cyberspace relationships and their influence on the mate selection methods are discussed. In this study, family attachment, traditional values and the level of religiosity are effective in young people attitudes to cyberspace mate selection, as well as effective variables have an impact on mate selection method with a coefficient of 0.611% were able to predict changes. In other words, effective independent variables have been able to define 0.611% of changes in mate selection methods, and the rest of the effects are due to some variables that are not included in this study.

The present research has been done with the aim of determine the relationship between intellectual capital and employee performance of Ports and Maritime Organization. Statistical population of the present study includes head office employees of Tehran Ports and Maritime Organization. The statistical population is 140 people, 103 samples were selected according to Morgan table. In this research, field study and the standard questionnaire of intellectual capital of Bontis (1998) and employee performance of Hersey and Goldsmith (1980) have been used as data collection tools, In order to describe the data, descriptive statistics to analyze the data and Kolmogorov Smirnov test and Pearson's correlation coefficient have been used to evaluate the research hypotheses .Statistical analysis has been done by using SPSS software. According to the results of this research there is a significant relationship between the dimensions of intellectual capital (human capital, structural capital, relational capital) with the performance of Ports and Maritime Organization, and intellectual capital and its dimensions was not assessed at desirable level in the Ports and Maritime Organization with an average rate of 3.224 as well as the performance of employees was not assessed at desirable level in the Ports and Maritime Organization with the Average Rate of 3.468 .

Hail phenomenon is one of the hazardous weather phenomena that can make the highest amount of damage to farms, gardens, cars, rooftops, etc. in a very short time (a few minutes), depending on the diameter of the particles. One of the best ways to study this devastating climatic phenomenon is the use of atmospheric instability indices. The indices which are calculated with the help of radiosonde data give a fairly comprehensive vision regarding the occurrence of such phenomenon. In this study, the incidence of moderate to severe hail is investigated in the period of 1990-2010. First, the atmospheric codes related to hail phenomena were applied to extract the data, then radiosonde data in intended time were received and applying the RAOB software, the physical status of atmosphere was studied. In the studied period, two hail examples were reported on November 27, 2008 and December 5, 2008. In the first instance of hail that occurred on November 27, 2008, the status of some indicators was calculated and it was found that LCL was at an altitude of 284 meters, CCL at an altitude of 1582 meters, LFC at an altitude of 6230 meters, the ice surface at an altitude of 3278 meters, the LI index was -0.2, the K index was 25.7 ° C, and PWC was 28 mm. In the above mentioned conditions, there was a hail with a diameter of 25.4 mm. In the second instance of hail that occurred on December 5, 2008, the status of some indicators was calculated and the results showed that LCL was at an altitude of 280 meters, CCL at an altitude of 1762 meters, LFC at an altitude of 2271 meters, the ice surface at an altitude of 2771 meters, the LI index was -1.4, the K index was 27.1 ° C, and PWC was 23.6 mm. In the above mentioned conditions, there was a hail with a diameter of 3.6 mm. Given that in many ways, the status of most atmospheric indicators in the two above examples of hail were close to each other, it turns out that in similar circumstances, the greater the distance the ice level gets to the summit of cloud, the greater is the probability of hails larger in diameter. The value of this distance for November 27, 2008 was at approximately 6384 meters and for December 5, 2008, it was at about 5012 meters.