HACCP在观赏鱼配合饲料中的应用

本文对HACCP对观赏鱼配合饲料的应用进行了分析,并提出了相应的风险质量管控措施,仅供参考。     

银行信贷风险预警的动态模型

通过对信贷风险的形成机理、内涵及后果的进行理论分析,利用GM(1,1)模型,建立银行信贷风险预警的动态模型,提出防范银行信贷风险的对策和建议。     

Client Focus,Cooperation, and Coherence: (Re)professionalising Processes for Elderly Care

This paper suggests the study of professionalism and the professionalising processes within public sector organisations. Sociologists propose that professionalism is changing into a new variant developing under the premise of organisational management and control. This paper disputes the perspective that the use of management control leads to deprofessionalisation in terms of the routinisation of reflective professional tasks or weakened professional values. This paper proposes that, with client focus, professionals and accountants can cooperate and create coherence between management control system elements and professional values. This dynamic contributes to the retention of professional values and more reflective work procedures.     

Optimal execution with uncertain order fills in Almgren–Chriss framework

The classical price impact model of Almgren and Chriss is extended to incorporate the uncertainty of order fills. The extended model can be recast as alternatives to uncertain impact models and stochastic liquidity models. Optimal strategies are determined by maximizing the expected final profit and loss (P&L) and various P&L-risk tradeoffs including utility maximization. Closed form expressions for optimal strategies are obtained in linear cases. The results suggest a type of adaptive volume weighted average price, adaptive percentage of volume and adaptive Almgren–Chriss strategies. VWAP and classical Almgren–Chriss strategies are recovered as limiting cases with a different characteristic time scale of liquidation for the latter.     

碳排放权交易、损益偏离与绿色经济效率关系研究

"双碳"目标展现了中国作为负责任的大国,对建设人类命运共同体的担当,碳排放权交易是实现这一目标的重要途径,但其对地区经济与环境的双重影响依然有待检验。结合1997—2017年中国省级数据,采用包含非期望产出的SBM-DEA模型测度地区绿色经济效率,以碳排放权交易试点为准自然实验,运用合成控制法评估试点政策对地区绿色经济效率的影响,并采用空间计量模型从损益偏离视角展开机制检验。研究发现:碳排放权交易试点政策能够显著提升地区经济效率,运用双重差分模型和PSM-DID进行稳健性检验后,基本结论依然可靠。缓解"收益在外,污染在内"的损益偏离现象,是碳排放权交易试点机制提升绿色经济效率的有效途径。随后提出通过进一步完善碳排放权交易市场机制,进而推动我国绿色发展的相关政策启示。     

西北半干旱地区既有城市道路海绵化 改造模式探索——以西宁为例

西宁属于西北高海拔半干旱地区,具有年均降雨量 少、蒸发量高的气候特征。城市道路是城市径流雨水产流的主 要组成部分。西宁现状城市道路均采用传统快排方式,存在雨 水利用不佳、污染城市末端水系生态环境等问题。根据城市道 路等级、下垫面及现状植被生长情况,分析西宁海绵城市建设 试点区道路改造项目的特点,定制城市道路海绵化改造的技术 路线,分类探讨解决西北半干旱地区城市道路初期雨水的径流 污染控制及雨水利用问题。根据已完成海绵化改造的8条道路 的经验,提炼西宁城市道路海绵化改造模式,以期为西北半干 旱地区城市道路海绵化改造提供解决思路。     

基于径流路径优化的校园景观海绵化 改造研究——以天津大学青年湖片区为例

校园中以硬质铺装为主的场地能够满足师生日常公 共活动需求,然而集中的不透水地面、屋面会增大场地雨洪压 力。在保证硬质下垫面功能属性的同时,实现雨洪的有效管控 是校园景观海绵化改造的核心问题之一。通过获取高精度的 场地空间数据,构建SWMM概化模型,分析不同暴雨重现期 下不同场景的径流量、峰值流量、峰现时间及不同排水口的流 量变化规律,得出基于径流路径优化的校园景观海绵化改造对 策,即以优化雨水径流路径为导向,适当组织线性GSI措施, 引导产汇流方向,降低场地中有效不透水面积(EIA),减轻场 地雨洪压力。最后结合青年湖片区的景观现状,提出以优化径 流路径为导向的系统化、立体化、适地性、可观赏的校园雨洪 管理模式,对于中小尺度公共空间海绵化改造实践具有实操价 值和指导意义。     

Optimal excess-of-loss reinsurance contract with ambiguity aversion in the principal-agent model

ABSTRACT

We discuss an optimal excess-of-loss reinsurance contract in a continuous-time principal-agent framework where the surplus of the insurer (agent/he) is described by a classical Cramér-Lundberg (C-L) model. In addition to reinsurance, the insurer and the reinsurer (principal/she) are both allowed to invest their surpluses into a financial market containing one risk-free asset (e.g. a short-rate account) and one risky asset (e.g. a market index). In this paper, the insurer and the reinsurer are ambiguity averse and have specific modeling risk aversion preferences for the insurance claims (this relates to the jump term in the stochastic models) and the financial market's risk (this encompasses the models' diffusion term). The reinsurer designs a reinsurance contract that maximizes the exponential utility of her terminal wealth under a worst-case scenario which depends on the retention level of the insurer. By employing the dynamic programming approach, we derive the optimal robust reinsurance contract, and the value functions for the reinsurer and the insurer under this contract. In order to provide a more explicit reinsurance contract and to facilitate our quantitative analysis, we discuss the case when the claims follow an exponential distribution; it is then possible to show explicitly the impact of ambiguity aversion on the optimal reinsurance.     

Predicting credit card fraud with Sarbanes‐Oxley assessments and Fama‐French risk factors

This research developed and tested machine learning models to predict significant credit card fraud in corporate systems using Sarbanes‐Oxley (SOX) reports, news reports of breaches and Fama‐French risk factors (FF). Exploratory analysis found that SOX information predicted several types of security breaches, with the strongest performance in predicting credit card fraud. A systematic tuning of hyperparamters for a suite of machine learning models, starting with a random forest, an extremely‐randomized forest, a random grid of gradient boosting machines (GBMs), a random grid of deep neural nets, a fixed grid of general linear models where assembled into two trained stacked ensemble models optimized for F1 performance; an ensemble that contained all the models, and an ensemble containing just the best performing model from each algorithm class. Tuned GBMs performed best under all conditions. Without FF, models yielded an AUC of 99.3% and closeness of the training and validation matrices confirm that the model is robust. The most important predictors were firm specific, as would be expected, since control weaknesses vary at the firm level. Audit firm fees were the most important non‐firm‐specific predictors. Adding FF to the model rendered perfect prediction (100%) in the trained confusion matrix and AUC of 99.8%. The most important predictors of credit card fraud were the FF coefficient for the High book‐to‐market ratio Minus Low factor. The second most influential variable was the year of reporting, and third most important was the Fama‐French 3‐factor model R² – together these described most of the variance in credit card fraud occurrence. In all cases the four major SOX specific opinions rendered by auditors and the signed SOX report had little predictive influence.