DIVERSIFICATION GAINS FROM INCLUDING REAL ESTATE IN MIXED-ASSET PORTFOLIOS*

Diversification gains in mean-variance efficiency derived from including real estate in financial asset portfolios are examined. Optimal financial and mixed-asset portfolios were generated by selecting from an investment universe including several distinct financial and real estate media. Deficiencies of previous studies were overcome by employing data with improved representativeness and comparability. The efficient mixed-asset portfolios dominated the efficient financial asset portfolios implying that purely financial asset diversification is inefficient. The optimal mixed-asset portfolio prescribed that approximately two-thirds of the investment wealth be allocated to real estate and one-third to the financial media.     

ON THE DESIGN OF HIERARCHICAL PRODUCTION PLANNING SYSTEMS

To provide effective managerial support for decisions related to production planning and scheduling processes, it is useful to partition the set of decisions into a hierarchical framework. In the resulting system, higher level decisions impose constraints on lower level actions, and lower level decisions provide the necessary feed-back to reevaluate higher level actions. The purpose of this paper is to suggest optimum procedures to deal with the resulting subproblems and to analyze the interaction mechanisms among the different hierarchical levels. Computational results are given.     

THE DETAIL SCHEDULING OF A PART-TIME WORK FORCE: A CASE STUDY OF TELLER STAFFING

This paper presents a comparison of two heuristic methods for assigning a part-time work force to meet varying daily work loads. The authors use actual operating data from Purdue National Bank, Lafayette, Indiana, to make teller staffing decisions. The performance criteria for comparison of the two heuristics is the minimum number of workers employed, minimum number of interbranch transfers, and computer time necessary to attain a solution.     

近600年来我国的旱灾与瘟疫

根据有关历史文献、气象资料、报表和地方志的统计结果 ,15— 19世纪 ,全国共发生旱灾 15次 ,总历时 4 9年 ,其中 14次有瘟疫伴生。北方旱灾 14次 ,13次有瘟疫伴生 ;南方旱灾 7次 ,均有瘟疫伴生 ,有 6次南北同旱。 2 0世纪 ,全国共发生旱灾 18次 ,其中 ,北方旱灾 17次 ,两次有瘟疫伴生 ;南方旱灾 11次 ,1次有瘟疫伴生。 2 0世纪的灾害发生率是前 5 0 0年的 6倍。该文指出 ,这是由于在全球工业化过程中 ,不断增加的温室气体产生了温室效应 ,使气候变暖、降水减少、持续冬暖所致。因此 ,该文建议加快实施西部开发 ,治理环境 ,实施节水、调水工程 ,提高防灾抗灾能力 ,以缓解南北旱灾和瘟疫的发生     

对西部林业生态环境建设资源配置方式的探讨

资源配置的方式是西部林业生态环境建设的重要问题 ,它决定着资源的合理利用和效益大小 ,也影响着我国西部地区经济发展的进程。该文探讨了在西部大开发的背景下 ,在林业实施跨越式发展的形势所需下 ,西部所进行的林业生态环境建设 ,如何进行资源配置方式的选择。在分析了关于计划和市场两种资源配置方式的观点后 ,认为根据西部目前的现实状况 ,西部林业生态环境建设应实行计划和市场相结合的资源配置方式     

The multinational transfer of competency-based foster parent assessment, selection, and training: a nine-country case study.

The UN Convention on the Rights of the Child mandates (Articles 19 and 20) that alternative care be available to protect children from maltreatment by parents and caregivers. Increasingly, countries around the world have recognized the benefits to child well-being of family-based care as an alternative to institutional care. The special if not extraordinary needs of children separated from parents because of abuse, neglect, and maltreatment and placed with foster families requires a commensurate effort to develop foster families who have special if not extraordinary skills. Methods that are effective and replicable across countries offer significant advantages, reducing investments in policies and practices that otherwise would have to be developed independently, country by country. This case study describes the factors that contributed to the transfer of knowledge in the assessment, selection, and training of foster parents and the impact to date.     

Construction Safety Risk Modeling and Simulation

By building on a genetic‐inspired attribute‐based conceptual framework for safety risk analysis, we propose a novel approach to define, model, and simulate univariate and bivariate construction safety risk at the situational level. Our fully data‐driven techniques provide construction practitioners and academicians with an easy and automated way of getting valuable empirical insights from attribute‐based data extracted from unstructured textual injury reports. By applying our methodology on a data set of 814 injury reports, we first show the frequency‐magnitude distribution of construction safety risk to be very similar to that of many natural phenomena such as precipitation or earthquakes. Motivated by this observation, and drawing on state‐of‐the‐art techniques in hydroclimatology and insurance, we then introduce univariate and bivariate nonparametric stochastic safety risk generators based on kernel density estimators and copulas. These generators enable the user to produce large numbers of synthetic safety risk values faithful to the original data, allowing safety‐related decision making under uncertainty to be grounded on extensive empirical evidence. One of the implications of our study is that like natural phenomena, construction safety may benefit from being studied quantitatively by leveraging empirical data rather than strictly being approached through a managerial perspective using subjective data, which is the current industry standard. Finally, a side but interesting finding is that in our data set, attributes related to high energy levels (e.g., machinery, hazardous substance) and to human error (e.g., improper security of tools) emerge as strong risk shapers.     

Conditional moving linear regression: Modeling the recruitment process for ALLHAT

Effective recruitment is a prerequisite for successful execution of a clinical trial. ALLHAT, a large hypertension treatment trial (N = 42,418), provided an opportunity to evaluate adaptive modeling of recruitment processes using conditional moving linear regression. Our statistical modeling of recruitment, comparing Brownian and fractional Brownian motion, indicates that fractional Brownian motion combined with moving linear regression is better than classic Brownian motion in terms of higher conditional probability of achieving a global recruitment goal in 4-week ahead projections. Further research is needed to evaluate how recruitment modeling can assist clinical trialists in planning and executing clinical trials.