라이브 스트리밍 커머스 중 라이브 인터페이스가 소비자 구매의도에 미치는 영향에 관한 연구

WANG ZHENG 경희대학교 대학원 2022 국내석사

In order to satisfy the consumer needs of many shoppers, shopping malls satisfy consumers in various aspects. We are doing our best to satisfy consumers in both the environmental construction of the shopping mall and the shopping atmosphere created by the sales staff of the shopping mall. Currently, studies on the offline shopping mall environment and consumer purchasing behavior in China and abroad are relatively abundant. And there are quite a few studies on online shopping, that is, shopping through live streaming. The research direction of the existing live streaming can be divided into two major studies: the study of anchors and the study of the atmosphere of live streaming. However, research on the online streaming interface, that is, the environment of the broadcasting room, will not be seen yet. As mentioned earlier, offline shopping malls must consider the shopping environment and shopping atmosphere. If so, I wonder if the environment provided by the live streaming room should also consider these two. Although consumers cannot directly enter the scene of the broadcast room, can consumers be influenced by the live streaming interface to influence their purchasing behavior while watching the live stream? Based on the above research ideas, the shopping environment was subdivided according to related theories and research results. That is, a virtual online broadcasting interface; an artificially configured user interface; Instant social interaction interface; A carefully crafted business interface has been subdivided into four categories. Since this study intends to study the four interfaces of a live streaming room, it does not do a detailed study on the atmosphere of the broadcasting room, so one point of interaction between anchors and consumers in the live streaming room is limited. Based on this, this paper builds a relationship model between various interfaces of a live streaming broadcasting room and consumers' purchase intentions using emotional flow (FE) and media attachment (MA) as parameters, and analyzes the relationship between various factors in depth. We want to verify the conceptual model. And, by presenting research hypotheses through normative empirical analysis and discussing the results of the hypotheses, it is intended to reveal the theoretical value of this study and its practical and guiding significance to create a better interface for live streaming rooms. Before starting this study, an in-depth analysis of previous studies and related theoretical studies was performed. I did an in-depth study on “what is a live streaming interface” and “what aspects of a live streaming interface are included”. Second, according to the existing literature on live streaming research, emotional flow (FE) and media attachment (MA) theories are frequently used as parameters in related research models. Third, based on the aforementioned live streaming interface and the framework of emotional flow (FE) and media attachment (MA) theories, we present a hypothesis to create and test a conceptual model with purchase intention. Fourth, this thesis uses empirical research as the main research method to secure the scientificity of the research results. After developing an initial scale suitable for the requirements of this study, data are collected through preresearch testing and the second data collection. do. After the reliability and validity test, we want to check the degree of fit of the model through exploratory and confirmatory factor analysis and verify the hypothesis through regression analysis. Fifth, we would like to present a proposal for improvement of the live streaming interface according to the results obtained from the data. Based on the research in this paper, the following conclusions are drawn: First, among the live streaming interfaces, the entrance interface and the broadcast interface have a significant effect on emotional flow and media attachment. However, payment interfaces were found to have a significant effect on media attachment, but no clear positive effect on emotional flow. Second, interim flow and media attachment will positively influence purchase intention, respectively. Finally, according to the conclusions and research of this paper, we make the following recommendations for live streaming room managers: (1) As a person in charge of live broadcasting, you should try to broaden the entrance to the broadcasting room and provide various ways for consumers to enter the broadcasting room through various platforms. Information from the live broadcast room should be made widely available for distribution on portal sites, browsers, forums and other places. Consumers can pay attention to the live broadcast room from multiple channels, which can not only achieve the purpose of promoting the live broadcast room, but also provide more means for consumers to enter the live broadcast room. (2) In the live broadcasting room, by adding a specific decoration, the environment of the live broadcasting room can be established, attracting consumers' attention, and increasing the probability that the consumer enters the live broadcasting room. It should be possible to provide “experiential (immersive)” broadcasting to consumers in the broadcast interface. “Experiential (immersive)” broadcasting includes both sensory and cognitive experiences. These broadcasts can stimulate consumers' emotional flow and increase their purchase intention. 다양한 새로운 비즈니스 모델의 출현으로 쇼핑몰 및 쇼핑 센터와 같은 전통적인 비즈니스 방식의 상황은 점점 더 어려워지고 있다. 오프라인 매장의 총 매출액은 더 천천히 성장하고 있다. 동시에 중국 경제가 더욱 발전함에 따라 온라인 소비는 점점 더 많이 찾는 소비 방법이 된다. 그리고 라이브 쇼핑의 회전율이 빠르게 증가하고 있다. 2017 년부터 2019 년까지 라이브 스트리밍 전자상거래 시장 규모는 전년 대비 200% 이상의 성장률을 보이며 높은 수준의 성장을 유지했다. 2021 년에는 라이브 스트리밍 전자상거래 산업의 매출이 1 조 위안을 넘었다. 중국 과학원의 예측에 따르면 라이브 스트리밍 전자 상거래는 앞으로 빠른 발전 추세를 유지할 것이지만 수익 증가율은 점차 둔화될 것이다. 주된 이유는 라이브 스트리밍 전자 상거래의 보급률이 증가함에 따라 "거친 성장"라는 트래픽 배당금이 점차 합리적으로 되기 때문이다. 많은 쇼핑객의 소비자 니즈를 충족시키기 위해 쇼핑몰은 다양한 측면에서 소비자를 만족시키고 있다. 쇼핑몰의 환경적인 건설이나 쇼핑몰의 영업직원이 만들어내는 쇼핑분위기에 모두 소비자를 만족시키기 위해 최선을 다하고 있다. 현재 중국 국내외 오프라인 쇼핑몰 환경과 소비자의 구매 행동에 대한 연구는 상대적으로 풍부하다. 그리고 온라인 쇼핑, 즉 라이브 스트리밍을 통한 쇼핑에 대한 연구는 상당히 많다. 기존의 라이브 스트리밍의 연구 방향은 크게 앵커에 대한 연구와 라이브 스트리밍의 분위기에 대한 연구로 두 가지로 나눌 수 있다. 그러나 온라인 스트리밍 인터페이스에 대한 연구는 아직까지 적게 보일 것이다. 앞서 언급했듯이 오프라인 쇼핑몰은 쇼핑 환경과 쇼핑 분위기를 고려해야 한다. 그렇다면 라이브 스트리밍 방송실에서 제공하는 환경도 이 두 가지를 고려해야 할지 아닐까 싶다. 소비자가 직접 방송실의 현장에 들어갈 수는 없지만 라이브 스트리밍 인터페이스의 영향을 받아 라이브 스트리밍을 시청하는 과정에서 구매 행동에 영향을 미치게 될 수 있다. 이상의 연구 아이디어를 바탕으로 쇼핑몰 외부적인 환경을 관련 이론과 연구 결과에 따라 쇼핑환경을 세분화 하였다. 즉 생방송실로 들어가기 전에 보이는 입구 인터페이스와 방송 인터페이스, 그리고 마지막으로 결제할 때 보이는 지불 인터페이스 이 3가지로 나눌 수 있다. 본 연구는 라이브 스트리밍 룸의 3 가지 인터페이스 연구하고자 하니 방송실의 분위기에 대한 세분화된 연구를 하지 않으므로 라이브 스트리밍 룸에서의 앵커와 소비자의 상호작용이라는 한 점을 제한된다. 이를 바탕으로 본 논문에서는 감정적 흐름(FE)과 미디어 애착(MA)을 매개변수로 하여 라이브 스트리밍 방송실의 다양한 인터페이스와 소비자의 구매의도 간의 관계 모형을 구축하고 다양한 요소들 간의 관계를 심층적으로 분석하여 개념 모형을 검증하고자 한다. 그리고 규범적 실증분석을 통해 연구 가설을 제시하고 가설의 결과를 논의함으로써 본 연구의 이론적 가치와 더욱 좋은 라이브 스트리밍 룸의 인터페이스를 만들기 위한 실천적이면서 지도적인 의의를 밝히고자 한다. 먼저 본 연구를 시작하기 전에 선행 연구 및 관련 이론 연구에 대한 심층 분석을 수행하였다. “라이브 스트리밍 인터페이스가 무엇인가 ”,”라이브 스트리밍인터페이스가 어떤 측면이 포한 되어 있는 지”에 대한 깊이 있게 연구를 해 보았다. 둘째, 라이브 스트리밍 연구에 대한 기존 문헌에 따르면 감정적 흐름(FE)과 미디어 애착(MA) 이론은 관련 연구 모델에서 매개변수로 자주 사용된다는 것을 알게 되었다. 셋째, 앞서 언급한 라이브 스트리밍 인터페이스와 감정적 흐름(FE)과 미디어 애착(MA) 이론의 틀을 바탕으로 구매의도와의 개념적인 모델을 만들고 테스트할 가설을 제시한다. 넷째, 본 논문은 연구결과의 과학성을 확보하기 위해 실증적 연구를 주된 연구방법으로 하고 있으며, 본 연구의 요구사항에 적합한 초기 척도를 개발한 후 연구 사전 테스트와 제 2 회의 자료 수집을 거쳐 데이터를 수집한다. 신뢰성 및 타당성 검정 후 탐색적 및 확인적 요인분석을 통해 모형의 적합한 정도를 확인하고 회귀분석을 통해 해당 가설을 검증하고자 한다. 다섯째, 데이터로부터 얻은 결과에 따라 라이브 스트리밍 인터페이스의 개선을 위한 제안을 제시하고자 한다. 본 논문의 연구를 바탕으로 다음과 같은 결론을 내린다: 첫째, 라이브 스트리밍 인터페이스 중의 입구 인터페이스, 방송 인터페이스가 감정 흐름과 미디어 애착에 유의한 영향을 미친다. 그러나 지불 인터페이스는 미디어 애착에 유의한 영향을 미치지만 감정 흐름에 분명한 긍정적인 영향을 미치지 않다는 것으로 나타났다. 둘째, 잠정 흐름과 미디어 애착이 각각 구매의도에 긍정적으로 영향을 미칠 것이다. 마지막으로 본 논문의 결론과 연구에 따르면 라이브 스트리밍 룸 담당자에게 다음과 같은 제언을 합니다: (1)라이브 방송 담당자로서 방송실 입구를 광범위하게 확대하고 다양한 플랫폼을 통해 소비자가 방송실로 입장할 수 있는 다양한 방법을 제공하도록노력해야 한다. 라이브 방송실의 정보는 포털 사이트, 브라우저, 포럼 및 기타 장소에 널리 배포될 수 있게 해야 한다. 소비자는 여러 채널에서 라이브 방송실에 관심을 기울일 수 있으므로 라이브 방송실을 홍보하는 목적을 달성할 수 있을 뿐만 아니라 소비자가 라이브 방송실에 들어갈 수 있는 더 많은 수단을 제공할 수 있다. (2)라이브 방송실에서 특정한 장식을 추가하여 라이브 방송실의 환경을 구축하여 소비자의 관심을 끌 수 있고 소비자가 라이브 방송실에 들어갈 확률을 높일 수 있다. 방송 인터페이스에서 소비자에게 “체험식(몰입식)” 방송을 제공할 수 있어야 한다. “체험식(몰입식)” 방송은 감각적 경험과 인지적 경험을 모두 포함한다. 이러한 방송을 통해 소비자들의 감정 흐름을 자극하면서 구매의도를 높일 수도 있다.

Electrophysiology of growing rat dorsal root ganglion neurons in culture

Wang, Zheng Rijksuniversiteit te Leiden] 1996 국내박사

(The) antecedents of reverse channel strategic choice in business-to-customer electronic markets

Wang, Zheng Sungkyunkwan University 2018 국내박사

Reverse channel is return of products from a customer to the supplier, enabling the merchant to recapture value. Benefits of reverse channels are regaining value, achieving a competitive advantage and promoting a positive environmental impact. Although not widely mentioned in academic literatures of the marketing domain, reverse channel management is an important component of ecommerce. In particular, a well-managed reverse channel can not only enhance customer relationship management, but also support firm’s strategic marketing. Product returns, which erodes producers’ profits, has been one of the major challenges resulting from the rapid growth of ecommerce. The virtualization of the online business makes the high uncertainty of transaction which leads to the increasing amount of returns. In particular, unlike reverse channel in the B2B transaction where products generally return back in bulk, product returns in the B2C market is relatively complex. It is because of the fragmentation characteristic that the product return comes from various individuals in different places, and due to varying reasons—customers may regret over an impulsive buying, or quality of the product may be out of his/her expectation, or the virtual product description may be inaccurate. Extant papers largely illustrated that using coordination contracts or strict return policies can resolve or reduce customer returns, whereas in practice, many anecdotal evidences have delineated that providing return policies or contract alone is not sufficient to improve and reduce customer returns in ecommerce market. This dissertation aims to delineate a new designed reverse channel strategy—the Reversed Deposition Center (RDC)—proposed by a market maker in the B2C context. Since the success of this new designed channel system depends not only on the value the maker can provide for the participant firms, but also on the responses of the participant firms, the author investigates the factors that influence the choice decision of firms’ participation in RDC building on motivation-ability framework with transaction cost theory and resource based view. Laying out an understanding of the suppliers’ participation would enable the market maker to make his RDC more attractive to participant firms, and would enable other platform market makers like Alibaba or Amazon to deliberate the homologous reverse channel strategy in the future. By compiling a comprehensive dataset according to three steps bilateral sided interviews and using firm-level survey data in JD—one of the largest B2C market maker in China—the author specifies an ordinal logit regression model estimates and identifies parameters of each antecedent. Results point out that efficiency motive is a crucial determinant for supplier’s adopting on RDC, positively associates with the degree of supplier’s participation states. In accordance with the results of prior research, organizational abilities are confirmed as effective antecedents for organizational strategic choice. Especially, a supplier’s logistics capacity and communication capacity influence his decision on whether use the RDC or not. The results disclose that when a supplier possesses a stronger level of logistics capability, she/he has lower likelihood of adopting RDC; whereas frequency communication with the market maker makes increasing the probability of choosing RDC as a reverse channel strategy for a supplier. In addition, the author found that the effect of supplier’s customer orientation and his/her perception of the behavioral uncertainty of the market maker are substitutable, in which customer orientation can positively impact supplier’s RDC choice only when the supplier perceives the market maker has high behavioral uncertainty. Moreover, the positive effect of communication capacity is stronger when the supplier perceives the market maker has lower versus higher behavioral uncertainty. Drawing on empirical findings, the author discusses the theoretical and managerial implications for reverse channel management and put forth some recommendations.

New marketing channels of China FMCG market : a case of Nongshim China

Wang,Zheng 성균관대학교 경영전문대학원 2010 국내박사

This thesis presents a comprehensive analysis of the new distribution channels of FMCG market, particularly the instant noodle manufacture, based on the case study of Nongshim Company in the China market. Research was divided into two parts: literature study of China distribution situation and case study of Nongshim China. In the literature study part I found two things. First, major changes in the Chinese macro-environment have made great changes of the distribution channels, which a new dynamically and radically reshaped channel structure has been formed in the domestic FMCG market in China. At present, hypermarkets, supermarkets, discount stores, convenience stores and other mass grocery retailers are the main distribution channels in the Chinese FMCG market. Second, marketing channels are the lifeline and they have a significant meaning for all instant noodle manufacturers. As the common consensus: ?Winning the channels? means ?Winning the market?, channel competition will still be the mainstream and will become more fiercely in the future. Nongshim Company has a long tradition for being the marketing leader in the South Korean ramen market, however, with only 1% market share, they failed to meet their expectations in the China market. Problems may result from many aspects, based on the analysis of Nongshim?s marketing performance and by interviewing with key informants in the respective marketing of Nongshim and its Beijing branch, I found distribution decline hindered Nongshim?s market share. In this thesis, the new marketing channels of China FMCG market analysis as well as Nongshim case study make several contributions to the marketing channels management literature that will be of interest to both academic researchers and practitioners. Moreover, some managerial implications will be drawn from the research, which will make this thesis more meaningful and practical.

다층 자기구성 네트워크 구조 안정화 를위한 Type-2 퍼지 C 평균 기반 다항식 신경망의 설계

Wang Zheng 수원대학교 2021 국내박사

In this thesis, a design methodology based on type-2 fuzzy c means-based polynomial neural networks for stabilized self-organizing networks structure is introduced to cope with over-fitting as well as multi-collinearity problems which generally appear in conventional fuzzy neural networks. The design method of the proposed self-organizing networks structure provides an efficient solution to construct the type-2 fuzzy c means-based polynomial neural networks(T2FPNNs) through a synergy of multiple techniques such as L2-norm regularization, probability theory, and multi-optimization, in order to generate the structure of the multi-layered self-organizing networks designed with the aid of the learning as well as novel structural design. Overall networks structure is realized with the aid of parallel networks structure with newly added inputs as well as effective neuron selection method through the exponential-based roulette selection technique for each layer in T2FPNNs, and the least square error estimation (LSE)-based learning method with L2-norm regularization is used for constructing the stabilized networks architecture, and their ensuring design methodologies result in alleviating the overfitting phenomenon and also enhancing the generalization ability. For the performance enhancement of T2FPNNs directly affected by some parameters such as the number of input variables, fuzzification coefficient, the number of clusters per each variable, and the order of polynomial in the consequent parts of the fuzzy rules, multi-particle swarm optimization (MPSO) is exploited for the effectively structural as well as parametric optimization of the proposed networks. That is, the multi-optimization helps achieve compromise between the better generation performance and the alleviated over-fitting in order to lead to the stabilization of the proposed multi-layered self-organizing networks structure realized with the aid of synergistic multi-techniques such as a) L2-norm regularization-based LSE learning, b) probability theory for effective neuron selection through the exponential-based roulette selection technique, and c) novel parallel networks structure including newly added inputs and neuron selection method. The performance of the proposed networks structure is quantified by comprehensive experiments and comparative analysis.

Optimal stopping and switching problems with financial applications

Wang, Zheng Columbia University ProQuest Dissertations & These 2017 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This dissertation studies a collection of problems on trading assets and derivatives over finite and infinite horizons. In the first part, we analyze an optimal switching problem with transaction costs that involves an infinite sequence of trades. The investor's value functions and optimal timing strategies are derived when prices are driven by an exponential Ornstein-Uhlenbeck (XOU) or Cox-Ingersoll-Ross (CIR) process. We compare the findings to the results from the associated optimal double stopping problems and identify the conditions under which the double stopping and switching problems admit the same optimal entry and/or exit timing strategies. Our results show that when prices are driven by a CIR process, optimal strategies for the switching problems are of the classic buy-low-sell-high type. On the other hand, under XOU price dynamics, the investor should refrain from entering the market if the current price is very close to zero. As a result, the continuation (waiting) region for entry is disconnected. In both models, we provide numerical examples to illustrate the dependence of timing strategies on model parameters. In the second part, we study the problem of trading futures with transaction costs when the underlying spot price is mean-reverting. Specifically, we model the spot dynamics by the OU, CIR or XOU model. The futures term structure is derived and its connection to futures price dynamics is examined. For each futures contract, we describe the evolution of the roll yield, and compute explicitly the expected roll yield. For the futures trading problem, we incorporate the investor's timing options to enter and exit the market, as well as a chooser option to long or short a futures upon entry. This leads us to formulate and solve the corresponding optimal double stopping problems to determine the optimal trading strategies. Numerical results are presented to illustrate the optimal entry and exit boundaries under different models. We find that the option to choose between a long or short position induces the investor to delay market entry, as compared to the case where the investor pre-commits to go either long or short. Finally, we analyze the optimal risk-averse timing to sell a risky asset. The investor's risk preference is described by the exponential, power or log utility. Two stochastic models are considered for the asset price -- the geometric Brownian motion (GBM) and XOU models to account for, respectively, the trending and mean-reverting price dynamics. In all cases, we derive the optimal thresholds and certainty equivalents to sell the asset, and compare them across models and utilities, with emphasis on their dependence on asset price, risk aversion, and quantity. We find that the timing option may render the investor's value function and certainty equivalent non-concave in price even though the utility function is concave in wealth. Numerical results are provided to illustrate the investor's optimal strategies and the premia associated with optimally timing to sell with different utilities under different price dynamics.

Characterization of lead leaching in drinking water distribution systems relative to water age and water quality parameters

Wang, Zheng-Ming Michael North Carolina State University 2007 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Lead (Pb) leaching has occurred in the water distribution systems (WDSs) of many cities and towns in the United States. This heavy metal can dissolve in drinking water from lead pipes, lead solders and lead-containing plumbing fixtures. Exposure to lead can be seriously hazardous to human health, especially to children. While the treated water from water treatment plants does not generally contain lead, physical and chemical conditions in WDSs may cause lead to leach into the drinking water. Although the seriousness of lead corrosion in drinking water has long been recognized and researchers have analyzed the chemical causes of lead leaching, the use of computer water quality models combined with water quality parameters to analyze spatial locations and areas where lead leaching may occur has not been detailed. This study characterizes water age and its influence on water quality; especially lead leaching, in WDSs. The goal is for water utility managers and operators to efficiently target areas prone to lead leaching in WDSs. The approach has three components, (1) calculating water ages utilizing a computer water quality model, (2) analyzing spatially distributed water age and lead occurrence levels, and (3) evaluating the influences of other routinely monitored water quality parameters on lead leaching in water distribution systems. A water quality model is a model that is upgraded from an existing hydraulic trunk-main model using geographic information systems (GIS) about the WDSs. The results used in this study were calculated from the water quality models that are allowed by the United States Environmental Protection Agency (US EPA) to be applied in evaluating water quality in water distribution systems. The qualifications are determined and outlined by the US EPA for the initial distribution system evaluation (IDSE) from the recently promulgated Stage 2 Disinfection and Disinfectant Byproduct Rule (EPA, 2006). We then calculated the water age using the GIS-assisted water quality model. Based on recent occurrences of lead leaching in several local utilities in North Carolina, we hypothesized that the lead leaching may correlate to the hydraulic residence time. We combined the calculated water age and water quality parameters sampled in water distribution systems utilizing spatial analysis tools in GIS. We geo-coded these data and spatially joined them based on street addresses. Matrices were generated for spatial database analyses to map the lead levels versus the building ages, and the water age, one of the results from the water quality model simulation. We tested the hypothesis using the data from three water utilities in North Carolina. Some of these data were gathered for compliance with the US EPA Lead and Copper Rule, and others for preventive measuring. We analyzed approximately 400 samples. To aid the test of the hypothesis, we evaluated the other water quality parameters and their influence to lead leaching. These consisted of pH, HPC, and nitrate measures, all of which are routinely monitored by water utilities. All of the analysis components use the spatial and water measurement data that are readily available to most utilities. The approach developed in this study can also be used to analyze other pollutants that may be regulated under the US EPA Safe Drinking Water Act in the future. Overlay of derived GIS maps, including water quality model simulation results, lead sampling data, and other routinely monitored water quality parameters will allow utility managers to target lead sample sites and allocate their scarce resources more efficiently to alleviate the problems.

Analysts' superiority in processing public information: Evidence from recommendation revisions

Wang, Zheng University of Maryland, College Park 2006 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In this paper, I study analysts' superiority over the market in processing publicly disclosed earnings information by examining a sample of recommendation revisions issued subsequent to annual earnings announcements within a short period of thirty trading days. The main findings of this study are as follows: First, I provide strong evidence that these recommendation revisions convey valuable information to the market for clarifying the long term implications of recently released earnings. These revisions significantly alter the market's belief about the value implications of announced earnings, suggesting that analysts do have superiority over the market in processing pubic information. Also, the extent of this superiority is positively related to analysts' performance in picking stocks and forecasting earnings. Recommendation revisions issued by analysts with superior performance can make the market revise its assessment about the value implications of previous earnings to a much greater extent than those issued by analysts with moderate performance. Moreover, the extent of this superiority increases with the level of information complexity of earnings signals. Analysts' information is even more valuable to the market for reevaluating previous earnings when the earnings information is more difficult to analyze. Lastly, on average, the extent of this superiority declines after Regulation Fair Disclosure, but still remains significant, suggesting that analysts do not solely rely on inside information from the management to interpret public information. Actually, the decline in the extent of superiority is more likely due to a great increase in the number of revisions issued by analysts whose expertise is not in processing public information. Prior studies document that investors also use subsequent earnings announcements to adjust their estimate of the value implications of previous earnings. This study finds initial evidence that when analysts' information and subsequent earnings announcements provide consistent predictions on how previous earnings is misinterpreted, subsequent earnings announcements become less useful to investors for updating their beliefs regarding the implications of previously released earnings. This paper also compares the extent of analysts' superiority in processing publicly released earnings information across industries and find that analysts exhibit a greater degree of superiority for firms in the manufacturing and retail industry.

Essays in Stochastic Modeling with Applications in Entrepreneurship and Healthcare

Wang, Zhengli Stanford University ProQuest Dissertations & These 2021 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In this thesis we present applications of stochastic modeling in entrepreneurship and healthcare. In Chapter 1 we model the creation of a new venture with a novel drift-variance diffusion control framework in which the state of the venture is captured by a diffusion process. The entrepreneur creating the venture chooses costly controls, which determine both the drift and the variance of the process. When the process reaches an upper boundary, the venture succeeds and the entrepreneur receives a reward. When the process reaches a lower boundary, the venture fails. The entrepreneur can choose between two different controls and wishes to determine the policy that maximizes the expected total reward minus total cost. We consider two variations of the model: one in which both boundaries are fixed, and one in which only the upper boundary is fixed but the lower is free. We derive closed-form expressions under which the optimal policy will be dynamic versus static and we prove that when the policy is dynamic it switches between the two controls at most once. The results reveal a subtle trade-off between the cost of the two controls, their drift and their variances, in which controls that are more expensive may be utilized more than controls that are less expensive. We also demonstrate that in the fixed boundary case the entrepreneur may wastefully use a more expensive control near the lower boundary to avoid hitting that boundary. This implies that efficient utilization of the two controls cannot happen when the entrepreneur does not have the freedom to choose when to abandon the venture.In Chapter 2 we model entrepreneurs' behavior when they engage in a simultaneous process of search and hypothesis testing. Entrepreneurs search for a set of strategic and operational choices that will maximize their venture's profits and they test the hypothesis that these profits exceed a minimum threshold of viability. We formulate a problem of the entrepreneur opportunity search process, where in each time period, the entrepreneur can stop and conclude, or choose an experiment from a set of strategic and operational options, implement it and observe the resulting profit. Using tools from machine learning to model the search process and tools from sequential hypothesis testing to model the testing procedure, we analytically characterize the optimal testing strategy for the resulting problem. We demonstrate that in certain scenarios the optimal testing strategy from ourframework and that predicted by the Lean Startup Theory are consistent, while in others they disagree.In Chapter 3 we present an application of stochastic modeling in healthcare. Conventional clinical trial designs adopt a fixed sample size and assume a standard type I error of 5% and type II error of 10% or 20%. While interim review of the results is possible to accelerate decision making, these designs are rigid because they do not allow changes in the design over time in response to the results accumulated, or adaptation of the type I and type II errors to reflect the potential benefits and risks of the treatment under study.

On the steady-state operation of loop heat pipe evaporators: Fundamentals and modeling

Wang, Zheng Clemson University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Fundamentals of flow and heat transfer in the loop heat pipe evaporator were studied for the purpose of exploring evaporator characteristics and modeling evaporator operation. In the present study, major research efforts were directed toward the phase-change heat transfer in the wick structure and thermal-fluid behavior in the liquid core. The investigation in this field improves the understanding of fundamentals related to evaporator operation and thus presents prior knowledge for evaporator modeling. With this prior knowledge, a comprehensive mathematical model was developed to investigate the steady-state evaporator operation. Fundamental flow and heat transfer in the wick structure with phase-change, including the two-phase zone formation and phase-change behavior in the two-phase zone, were studied. Using a one-dimensional flow and heat transfer analysis, the two-phase zone formation in the wick structure was explored and related to loop operating conditions. An evaporation limit was also presented in the wick to connect continuum-scale two-phase behavior with pore-scale interfacial transport processes. Phase-change heat transfer was experimentally and theoretically investigated in large-pore wick structures. Owing to regular pore geometry and large pore size, the phase-change behavior was visually observed at the pore-level. Based on experimental observations, an analytical model was developed to describe the two-phase behavior and interfacial heat and mass transfer in the wick structure. The flow and heat transfer in the liquid core was numerically simulated to explore the thermal-fluid behavior and vapor generation mechanism. It was indicated that the maximum temperature appears at the stagnation point of the wick/core interface, which suggests that the vapor may be generated on the inner wick surface if a liquid superheat necessary for bubble nucleation is present at the stagnation end of the liquid core. Two typical geometrical configurations used for the liquid core, circular core and annular core (bayonet core), were considered to examine the bayonet effects on evaporator operation. It was found that the presence of a bayonet significantly affects the flow and heat transfer in the liquid core and helps to prevent vapor bubbles from accumulating inside the liquid core. A comprehensive mathematical model on steady-state evaporator operation was developed to describe the operational characteristics and evaluate evaporator performance. Numerical solutions were obtained for conjugate flow and heat transfer in the wick structure, the liquid core and the bayonet. The influences of input heat flux, inlet liquid subcooling, external loop resistance and effective thermal conductivity of the wick structure on evaporator performance were also studied. It was observed that increasing the applied heat flux and inlet liquid subcooling decreases the maximum temperature in the liquid core and helps to prevent vapor formation in the liquid core, which is favorable for proper evaporator operation. Decreasing the external loop resistance and effective thermal conductivity also decreases the maximum temperature in the liquid core. Additionally, increasing the applied heat flux and liquid subcooling significantly enhances the cooling capability of the liquid in the bayonet. This helps to prevent vapor bubbles from accumulating in the liquid core.