A Nonstationary Negative Binomial Distribution Applied to Coffee Purchase Data

Park, Heungsoo 연세대학교 산업경영연구소 1988 산업과경영 Vol.8 No.1

Negative binomial distribution(NBD) has been widely used as a stochastic model of purchase incidence, where the purchase process is assumed to be stationary. Sabavala and Morrison(1981) capture the dynamic nature of the process or the nonstationary behavior of the empirical process by extending the beta binomial model. Schmittlein, Bemmaor and Morrison (1985) compare the conditional expected mean of the NBD with the conditional expected mean of beta binomial/negative binomial as a way to measure the effect of the nonstationarity. This paper proposes another way to incorporate the nonstationarity behavior by providing a method to estimate the conditional expectation of NBD given the purchase history of past periods insead of just one past period. An optimum weighting scheme which combines the forecasted value and the actual value is the basis for obtaining the NBD conditional expectation given t period purchase history. Once the conditional expectation and the proportion of nonbuyers are estimated using the weighting scheme, the parameters of the nonstationary NBD are calculated using the series approximation method proposed by Morrison (1969b). The NBD so obtained is used to predict the mean number of buyers and the probability of nonbuyers of ground decaffeinated coffee. These values are compared with the values obtained with the stationarity assumption.

MODELING THE PRODUCT LEVEL CHOICE PROBLEM

Park, Heungsoo,Park, Jongseop 全州大學校 大學院 1994 全州大 論叢 Vol.5 No.-

소비자는 매일매일의 생활을 통해 여러가지 제품들 중 이용가치가 가장높은, 즉 최대 만족을 주는 제품을 선택하려고 한다. 이러한 가설을 중심으로하여 마케팅 관리자는 소비자에게 만족도를 극대화시킬수 있는 제품을 제공해야 한다. 이 문제를 PLC(제품 레벨 선택) 문제라고 부른다. 이 PLC 문제는 두개의 흐름이 있는데, 그 하나는 소비자가 여러가지 제품에 대한 대체능력의 습득이용에 중점을 두는 것이며 다른 하나는 소비자가 결정하는 실제적 선택 전략에 관한 것이다. PLC 문제의 추론과정은 주로 부수적 요구 (기분전환, 사회적 활동, 육체활동, 학구활동 등)를 가격분포와 결합하여 공식화한 모델로서 지출액에 대한 총 효용을 최대화하는 고객의 결정계산에 부응하도록 만들었다. 예를 들면 스키장비, 신사복, 자동차 등의 3가지 제품중에서 신사복은 육체활동에 있어 낮은 만족도를 나타낸 반면, 상대적으로 스 키장비는 사회 활동에 낮은 만족도를 나타내고 있다. 이러한 두가지 만의 차원을 가진 예문에서 마케팅 믹스를 통해 스키장비에 대한 어떠한 사회적 활동의 의미를 부여한다면 비용에 대한 전체적 만족도는 증가할 것이다라는 점이다. 즉, 한 제품이 한 차원에서 가치가 낮게 평가 되었을 때, 어떤 향상된 통계가 제품의 감각적 가치를 증가시킬수 있을지, 그래서 비용에 대한 기대치가 증가할 수 있을지를 테스트할 수 있다는 것이다. 이상에서 우리는 많은 영역에서 비용에 대한 전체 만족도를 극대화하는 제품을 소비자가 선택할 수 있도록 마케팅 관리자는 PLC문제의 모델을 발전시켜 실제 활용화에 박차를 가할 필요성이 있다고 본다.

A Model of Product Bundling

Park, Heungsoo 연세대학교 산업경영연구소 1992 산업과경영 Vol.10 No.1

This paper proposes an efficiency rationale for product bundling. Given initial prices of products and inventory-cost parameters for a buyer and a seller, it shows that product bundling reduces transactions cost and that a product-bundling strategy Pareto dominates a nobundling strategy. The number of product bundles offered by a seller, the constituent items of each bundle, and the number of units of each item in each bundle are considered to be decision variables in the model. Pricing mechanisms for splitting the efficiency gain in any desired proportion between the buyer and the seller using mixed-leader and mixed-joint bundling are presented. A dynamic-programming algorithm identifies optimal product bundles that maximize the gain in efficiency from product bundling.

A Nonstationary Negative Binomial Distribution Applied to Coffee Purchase Data

Heungsoo Park 연세대학교 경영연구소 1989 연세경영연구 Vol.26 No.2

A Model of Product Bundling

Heungsoo Park 연세대학교 경영연구소 1992 연세경영연구 Vol.29 No.1

<i>In situ</i> cross-linkable gelatin–poly(ethylene glycol)–tyramine hydrogel <i>via</i> enzyme-mediated reaction for tissue regenerative medicine

Park, Kyung Min,Ko, Ki Seong,Joung, Yoon Ki,Shin, Heungsoo,Park, Ki Dong Royal Society of Chemistry 2011 Journal of materials chemistry Vol.21 No.35

<P>An <I>in situ</I> cross-linkable gelatin–poly(ethylene glycol)–tyramine (GPT) hydrogel was developed as a novel injectable material for tissue regenerative medicine. The hydrogel was formed rapidly using horseradish peroxidase (HRP) and hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>). The gelation times could be controlled from five seconds to over one minute by changing the HRP concentration, and the mechanical properties could be controlled by varying the H<SUB>2</SUB>O<SUB>2</SUB> concentration. The storage moduli of the hydrogels ranged from approximately 200 to over 8000 Pa. In addition, an <I>in vitro</I> cell attachment study was carried out using various cell types. The results of this study demonstrated that the GPT hydrogel, formed <I>in situ via</I> an enzyme-mediated reaction, was an excellent bioactive matrix for cellular behavior. Furthermore, an <I>in vitro</I> 3D cell study was made using the GPT hydrogels formed with different mechanical strengths, and <I>in vivo</I> subcutaneous injection was carried out. The <I>in vitro</I> and <I>in vivo</I> studies demonstrated that the GPT hydrogels had excellent bioactivities, and that the cellular behavior in the hydrogel matrix could be controlled. The obtained results showed that these <I>in situ</I> forming GPT hydrogels, with excellent bioactivities and tunable physicochemical properties, have great potential for use as injectable materials in tissue regenerative medicine and various biomedical applications.</P> <P>Graphic Abstract</P><P>An <I>in situ</I> cross-linkable gelatin-poly(ethylene glycol)-tyramine (GPT) hydrogel was developed as a novel injectable material for tissue regenerative medicine. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm12527c'> </P>

<i>In situ</i> hydrogelation and RGDconjugation of tyramine-conjugated 4-arm PPO–PEOblock copolymer for injectable bio-mimetic scaffolds

Park, Kyung Min,Jun, Indong,Joung, Yoon Ki,Shin, Heungsoo,Park, Ki Dong The Royal Society of Chemistry 2011 SOFT MATTER Vol.7 No.3

<P>RGD-conjugated Tetronic–tyramine (RGD–Tet–TA) hydrogels were formed <I>in situ</I>, and cell attachment and spreading on the hydrogels were evaluated for an injectable tissue-regenerative scaffold. The hydrogels were prepared by simple mixing GRGDGGGGGY (RGD–Y) in a tyramine-conjugated Tetronic (Tet–TA) polymer solution in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>). The physico-chemical properties such as mechanical properties and swelling ratio were evaluated and the conjugated RGD concentration and distribution were measured using fluoresamine assay and fluorescence observation. An <I>in vitro</I>cell study was investigated using osteoblasts (MC3T3–E1) on the hydrogel surfaces for 24 h, in which the viability and morphology of the adhered cells were observed using live/dead and F-actin assays. The results demonstrate that the <I>in situ</I>conjugation of RGDpeptides to tyrosine residues enhanced the attachment and spreading of osteoblasts in a surface density-dependent manner. Therefore, this study suggests that <I>in situ</I>conjugation of the RGDpeptide to injectable hydrogels <I>via</I> an enzymatic reaction may be an efficient tool to prepare <I>in situ</I> forming bio-mimetic hydrogels for tissue regenerative medicine.</P> <P>Graphic Abstract</P><P>RGD-conjugated Tet-TA hydrogels were rapidly formed by an enzymatic reaction using HRP and H<SUB>2</SUB>O<SUB>2</SUB>. <I>In situ</I> conjugation of RGD peptide to tyrosine residues enhanced the attachment and proliferation of osteoblasts. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0sm00612b'> </P>

현대중국어 방향보어구조와 공기하는 장소명사(구)의 위치선정 기제

박흥수(Park, Heungsoo),이현숙(Lee, Hyunsuk) 한국중국어교육학회 2012 중국어교육과연구 Vol.0 No.16

漢語敎學中類詞綴“熱”的敎學初探

朴興株(Park, Heungsoo),??(Wu, Zhen) 한국중국어교육학회 2019 중국어교육과연구 Vol.0 No.29

“Quasi-affix” have been controversial in the academic world as a unique linguistic phenomenon. However, with the emergence of a large number of new words composed of quasi-affix in modern Chinese, the Chinese teaching outline also puts forward certain requirements for foreign students to master quasi-affix. However, as an important component of modern Chinese, the importance of word formation in Chinese teaching is not enough. The research results of analysis and teaching of specific quasi-affix in quasi-affix are rare. This paper takes the affix “Re” as an example, analyzes its semantics, structural characteristics and the importance of its teaching in Chinese teaching, and then summarizes the teaching method of affix “Re” in Chinese teaching, hoping to teach Chinese in the future. It is help to quasi-affix teaching in chinese teaching.

광고모델 선호도가 광고태도, 브랜드 태도 및 구매의도에 미치는 영향에 관한 연구

박흥수(Heungsoo Park),우정(Jeong Woo),김현정(Huynjeong Kim) 연세대학교 경영연구소 2006 연세경영연구 Vol.43 No.1