Study on Risk of Logistics and transport

Abstract. for logistics and transport security status quo， study and proposed transportation security risk evaluation index system； using whitening weight function design specific transportation security risk assessment model； verified by an example， that the evaluation method is more scientific and accurate comprehensive evaluationtransportation security situation， with the characteristics of the feasibility and operability.

Key words： evaluation； logistics； transportation risk management

1. Introduction

How to ensure the safety of transport， more and more public concern. But transportation security involves a wide range of influencing factors， and various influencing factors randomness， some factors both objectivity and subjectivity， it is difficult to quantify， the general safety evaluation method has some limitations. Of man - machine - environment - Principles of management systems， through the use of gray system theory， fuzzy math and expert scoring method established transportation safety evaluation model to evaluate the actual situation of the transport and use of the evaluation model， based on the results of some rationalization recommendations.

2. Transport safety risk assessment model

2.1 Evaluation index system

Transportation Safety Evaluation， follow the principle of comprehensiveness， highlight， independence and viability. Transportation Security conducted a comprehensive， systematic analysis of the transport system is a human - vehicle - environment - management system [4]. According to the actual situation of the four elements and the transport of dangerous goods， the analysis of all aspects of transport， to assess all aspects of the level of risk， screening crew factors， the five-level indicators of the factors of the ship， sailing environmental factors， management， institutional factors， and dangerous goods factors Ui and 21 secondary indicators Uij to build a transportation security risk evaluation index system， shown in Figure 1.

2.2 Evaluation index weight

The importance degree of each indicator affect safety during transport in transportation security risk evaluation index system. Given different weights should be based on the level of each indicator of the size of the Transportation Security. Based on various indicators with subjective expert scoring method to get the weight of all the experts， then the weight average weight requirements so closer to the actual situation of the transport of dangerous goods safety.Assumptions m bits experts are invited first to rate the importance of an evaluation， the result is noted as：

（i=1，2，…，5 ）， At the same time need to meet the conditions

， 。Each ，Corresponding to the weights can be obtained by scoring average of all experts， denoted as：

（1）

Where ， 。Determine the weight of the 21 second evaluation right. Uses the same expert scoring， and then averaging method. For example： the same invite experts in the m-bit set to u1） （5） of the two indicators of the first-level indicators （scoring， the result is noted as

，（ Secondary indicators），Then：

（2）

Wherein each column satisfy： ， ，

By calculating the average for each row of data. Two indicators can be obtained weights， denoted ，where i is number of expert。Weight according to the same method can be obtained for all other Layer indicators， denoted as：

（3）

Where ， （i=1，2，…5），ni is second Layer indicators。

2.3 Transportation security risk evaluation process

This transportation security risk level identified as level 5， namely： （4）

Five levels following meanings： safety， safer， general safety， more dangerous， dangerous} to five levels， respectively， given the values 1， 2， 3， 4， 5. Higher numbers indicate a greater security risk. When experts believe that one of two indicators of security risk rating is between two adjacent level of risk can be endowed numerical 1.5，2.5，3.5，4.5. Has m experts on indicators of 21 second-level evaluation for scoring， set the number of experts to k=1，2，…，m， is score of number k expert for uij。Sample matrix （see 5）.

（5）

Transportation risk level is determined to be 5： 1 - Security， 2 - safer - General Security， 4 - dangerous， 5 - dangerous. Serial v= 1，2， ... 5。

is whitening weight function，then ：

（6）

Whitening weight function to calculate （5） in the coefficient of the right value， the result is D‘，then：

（7）

The use of the formula （7） were calculated the secondary evaluation index weight vector.then： - 1- layer of indicators of risk level， ：2- layer of indicators of risk level，then：

， ，is：

（8）

an indicator of the weight vector can be calculated through （3） and （8）. Assume that the weight vector is Ai， are：

evaluation value of total logistics security risk rating isT：

Set ，G's size determines that what risk level for the transport of dangerous goods security risk ， and based on the results of analysis of causes and response measures.

3. Results Test

A logistics enterprises， for example， according to the transport of dangerous goods safety risk index system and gray fuzzy comprehensive evaluation model to assess the risk of transportation safety，by 13 Transportation Security expert interviews and actually research. To collate ， classificate and calculate the data given by these experts，Respectively determine the weight of a layer of evaluation：

Table 1 Second layer index weights：

After analysis calculated， =3.255.

Analysis of results： the logistics of the security situation in the general security more dangerous between the two levels， with a certain degree of risk， should take measures to strengthen prevention， especially in the secondary indicators， staffing levels， the level of security risk management generally partialfuture logistics enterprises should strengthen staff training， improve personnel management levels. The level of the average age of younger managers to comply with the requirements of the logistics staff.

4. Conclusion

Logistics is a modern transport with a vital significance， gray system theory and fuzzy mathematics security risk assessment and early warning of dangerous goods transportation， both able to better understand the transport safety risk status at the same time be able to be taken according to the results of the evaluationmeasures ，to reduce the level of risk. Therefore， the evaluation method has some scientific and practical value.

Reference

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