• Title/Summary/Keyword: Research Analysis

Search Result 97,850, Processing Time 0.143 seconds

Development of Carbonization Technology and Application of Unutilized Wood Wastes(II) - Carbonization and it's properties of wood-based materials - (미이용 목질폐잔재의 탄화 이용개발(II) - 수종의 목질재료 탄화와 탄화물의 특성 -)

  • Kong, Seog-Woo;Kim, Byung-Ro
    • Journal of the Korean Wood Science and Technology
    • /
    • v.28 no.2
    • /
    • pp.57-65
    • /
    • 2000
  • Objective of research is obtain fundamental data of carbonized wood wastes for soil condition, de-ordorization, absorption of water, carrier for microbial activity, and purifying agent for water quality of river. The carbonization technique and the properties of carbonized wood wastes(wood-based materials) were analyzed. Proximate analysis showed the wood-based materials contains 0.37~2.27% ash, 70~74% volatile matter, and 17~20% fixed carbon. As carbonization temperature was increased, the charcoal yield was decreased. However, no difference in charcoal yield was found due to time increase. The specific gravity after the carbonization decreased about 30~40% comparing to green wood. The charcoal had 1.08~4.18% ash, 5.88~13.79% volatile matter, and 80.15~90.94% fixed carbon. The pH of plywood and particleboard(pH 9 at $400^{\circ}C$, pH 10 at $600^{\circ}C$ and $800^{\circ}C$) made charcoals was higher than that of fiberboard. The water-retention capacity was not affected by the carbonization temperature and time. The water-retention capacity within 24h was about 2~2.5 times of sample weight, and the Equilibrium moisture content(EMC) became 2~10% after 24h. EMC of charcoal from the thinned trees were 9.40~11.82%($20^{\circ}C$, RH 90%), 6.87~7.61%($20^{\circ}C$, RH 65%), and 1.69~2.81%($20^{\circ}C$, RH 25%). EMC of charcoal from the wood-based materials under $20^{\circ}C$, relative humidity(RH) 90% was similar to EMC of charcoal from the thinned trees(9~11 %). However, under $20^{\circ}C$, RH 25.65%, EMC of charcoal from the wood-based materials were higher(2~3%) than EMC of charcoal from the thinned trees. Every charcoal from the wood-based materials fulfilled the criteria in JWWA K 113-1947.

  • PDF

An Analysis of Prognostic Factors Affecting the Outcome of Radiation Therapy for Nasopharyngeal Carcinoma (비인강암의 방사선치료 곁과 및 생존율에 관한 예후인자 분석)

  • Jung, Young-Yeon;Kim, Ok-Bae;Kim, Jin-Hee
    • Radiation Oncology Journal
    • /
    • v.23 no.2
    • /
    • pp.71-77
    • /
    • 2005
  • Purpose: This retrospective study was conduced to analyze the treatment results and to evaluate the prognostic factors affecting the survival of nasopharyngeal carcinoma patients. Materials and Methods: From 1987 to 2002, we analyzed 43 patients who had nasopharyngeal carcinomas that were histologically confirmed and who had also completed the planned radiation therapy course at Keimyung University Dongsan Medical Center According to the 6th edition of American Joint Committee on Cancer staging system, 12 patients ($27.9\%$) were at Stage 11, 13 ($30.2\%$) were at Stage III and 18 ($41.9\%$) were at Stage IV Histopathologically, there were 15 ($34.9\%$) squamous cell carcinomas, 8 ($18.5\%$) nonkeratinizing carcinomas, 17 ($39.5\%$) undifferentiated carcinomas, and 3 ($7.0\%$) lymphoepitheliomas. Among the total 43 patients, 31 patients ($72.1\%$) were treated with only radiation therapy. Neoadjuvant chemotherapy was peformed on 7 patients ($16.3\%$) and concurrent chemoradiotherapy was performed on S patients ($11.6\%$). Cisplatin and 5-Fluorouracil were administered to 11 patients for 4 cycles, and Cisplatin and Taxotere were administered to 1 patient for 6 cycles. The range of the total radiation dose delivered to the primary tumor was from 61.2 to 84 Gy (median 70.4 Gy), The follow-up period ranged from 2 to 197 months with median follow-up of 84 months. Results: The local control rate at 6 months after radiation therapy was $90.7\%$. The five year overall survival and disease free survival rates were $50.7\%$ and $48.9\%$, respectively. On the multivariate analysis, the age, T-stage ($T_{1-3}\;vs\;T_4$), N-stage and AJCC stage were the statistically significant prognostic factors affecting survival (p<0.05). The patterns of failure were as follows: local failure only in 3 patients ($7.0\%$), local and systemic failure in 1 patient ($2.3\%$), and distant metastasis only in 11 patients ($25.6\%$). Conclusion: The prognostic factors affecting the outcome of nasopharyngeal carcinoma were age, T-stage (7$T_{1-3}\;vs\;T_4$), N-stage and stage. Because systemic metastasis was the main failure pattern noted for nasopharyngeal carcinoma, systemic chemotherapy is needed to decrease the rate of distant metastasis for nasopharyngeal carcinoma. In audition, research for more effective chemotherapeutical regimens and schedules is also needed.

A Comparative Study on Hydraulic Jump and Specific Energy Losses at Downstream According to the Weir Discharge Types (보 유출형태에 따른 하류부 도수 및 비에너지 손실에 관한 비교 연구)

  • Park, Hyo-Seon;Yoon, Geun-Ho;Koo, Bon-Jin;Choi, Gye-Woon
    • Journal of Wetlands Research
    • /
    • v.15 no.1
    • /
    • pp.149-157
    • /
    • 2013
  • The weirs built so far are mainly overflow type weirs overflowing to the upstream. Main advantages of overflow type weirs are, effective water resources management and easy design, construction and maintenance due to many accumulated studies. However, due to the special feature of the overflow type weir where water overflows through the upstream of the weir, the silt coming from the upstream is not discharged to the downstream of the weir. This increases the river bed and reduces the reservoir capacity, and as a result, the weir loses its function. A underflow type weir with a water gate has been implemented in order to solve such sediment deposit and weir maintenance problems. However due to the design problem of recently constructed underflow type weirs, the river bed of the downstream of a weir has been scoured. And this leds to a structural problem. In this study, the flow characteristics of overflow type weirs and underflow type weir, hydraulic jump length analysis depending on change of water depth and the amount of specific energy loss generated per unit length depending on a weir type have been compared and analyzed, for the effective design and management of the weirs. The experiment results show that, when identical upstream conditions of underflow type weir and an overflow type weir were maintained, the hydraulic jump length was up to twice longer with Fr(Froude number) 3.5 of the hydraulic jump length at the underflow type weir, and the hydraulic jump length gradually decreased as the downstream water depth increased. The comparative analysis result of the amount of specific energy loss generated per unit length showed that the amount of energy loss per unit length was twice higher for an overlfow type weir than a underflow type weir. Therefore, in case of a underflow type facility, an additional energy reduction facility is determined to be necessary for safety of water construction structures.

Post-operative Radiation Therapy for Esophageal Cancer; Analysis of Failure Pattern (식도암의 수술 후 방사선 치료: 실패 양상 분석)

  • Kim Mi Sook;Kim Jae Young;Yoo Seoung Yul;Zo Chul Goo;Yoo Hyung Jun;Zo Jae Ill;Baek Hee Jong;Park Jong Ho;Choi Soo Yong
    • Radiation Oncology Journal
    • /
    • v.16 no.4
    • /
    • pp.447-454
    • /
    • 1998
  • Purpose : This study evaluated the survival, local control, prognostic factor, and failure pattern of patients with esophageal cancer treated with operation and adjuvant radiation therapy to use as fundermental data of postoperative radiation therapy. Materials and Methods : A retrospective analysis was undertaken of 82 patients who had locally advanced esophageal cancer treated with operation and adjuvant radiation therapy from January 1988 to December 1995. According to AJCC staging, stage IIA were in 26 patients, stage IIB in 4 patients, and stage III in 52 patients. Squamous cell carcinoma were in 77 patients, adenosquamous carcinoma in 3 patients, and adenocarcinoma in 2 patients. The patients received radiation therapy ranging from 41.0 Gy to 64.8 Gy. Five patients received neoadjuvant chemotherapy. Results : Two-year survival and local control rates for all patients were 36.8$\%$ and 30.4$\%$ respectively. And they were 9.3$\%$ and 26.3$\%$ respectively at 5 years. According to stages, 2-year survival rates were 50.2$\%$ in IIA, 0$\%$ in IIB and 23.3$\%$ in III (p=0.004). Two-year local control rates were 49.2 $\%$ in IIA, 66.6$\%$ in IIB and 24.7$\%$ in III (p=0.01). Sixty patients developed recurrence, which were 3 tumor margin, 23 lymph node recurrence, 4 tumor margin and lymph node, 1 tumor margin and distant metastasis, 9 lymph node and distant metastasis, 17 distant metastasis and 3 unknown metastatic site. Prognostic factors affecting survival were smoking (p=0.02), T-staging (p=0.0092), N-staging (p=0.0045). Prognostic factors affecting local control were T-staging (p=0.019), N-staging (p=0.047). Conclusion : In spite of post-operative radiation therapy, predominant failure pattern was local failure. Especially regional lymph node failure was major cause of local failure. So strategy of aggresive adjuvant radiation therapy to regional lymph node area in post operative treatment should be proposed.

  • PDF

Development of Dose Planning System for Brachytherapy with High Dose Rate Using Ir-192 Source (고선량률 강내조사선원을 이용한 근접조사선량계획전산화 개발)

  • Choi Tae Jin;Yei Ji Won;Kim Jin Hee;Kim OK;Lee Ho Joon;Han Hyun Soo
    • Radiation Oncology Journal
    • /
    • v.20 no.3
    • /
    • pp.283-293
    • /
    • 2002
  • Purpose : A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 30 dose distributions. Materials and Methods : Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dosevolume histogram. Results : The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a $200\times200\;(mm^2)$ plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were $4.5\~9.0\%$ smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed $1\~5\%$ discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. Conclusion : This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

A Study on Cold Damage(傷寒) in the Compendium of Prescription from the Countryside(鄕藥集成方) - Focusing on citation, medical theory, prescription, medicinal herbs - (조선 의서 『향약집성방』 중에 실린 상한(傷寒) 논의 연구 - 인용 문헌, 의론(醫論), 처방, 본초 등을 중심으로 -)

  • Oh, Chae-Kun
    • The Journal of Korean Medical History
    • /
    • v.25 no.2
    • /
    • pp.121-136
    • /
    • 2012
  • The purpose of this paper is to derive the features of cold damage clinical medicine during the early days of the Chosun(朝鮮) period by analyzing discussions on cold damage published in the official medical book of the Chosun period, Compendium of Prescription from the Countryside(鄕藥集成方, CPC). Cold damage was one of the typical diseases in East Asia where there was constant seeking of the utilization of prescriptions, ways of preparations, and awareness regarding cold damage as shown in Zhang, Zhongjing(張仲景)'s Treatise on Cold Damage Disease(傷寒論, TCDD) below. Traditional Korean medicine which possessed the medical universality of East Asia also was no exception and through an analysis of the part on cold damage in CPC, it is expected that medical features of cold damage in Korea passed down from the Koryo(高麗) Dynasty to the early Chosun period will be revealed. For this, first there needs to be an organization of past discussions on cold damage surrounding the existence of infection and after checking the issues, exploring which of the writings related to TCDD and editions are being utilized through an analysis on citing literature of Cold Damage Disease Literature(傷寒門) and Heat Pathogen Disease Literature(熱病門) which have developed discussions on cold damage in CPC. In addition, by comparing Peaceful Holy Benevolent Prescription(太平聖惠方, PHBP) and Complete Record of Sacred Benevolence(聖濟總錄, CRSB), known to have greatly influenced CPC and Cold Damage Literature and Heat Pathogen Disease Literature, features of form and content used by CPC were analyzed. Features of form were examined through pattern of organization and number of citing literature were examined and for features of content, cold damage infection, classification, syndrome differentiation method, and utilization of materia medica among prescriptions were examined. Discussions on cold damage as being uninfectious as stated in Treatise on the Pathogenesis and Manifestations of All Diseases(諸病源候論) unlike pestilence, epidemic pathogen(時氣), warm pathogen disease(溫病), and heat pathogen disease were excluded in PHBP. PHBP opened the possibility of cold damage infection and later writings, CRSB and CPC also follow this. As a result of analyzing citing literature of the part on cold damage in CPC, it is uncertain which edition of TCDD is being utilized; however, the most distinctive feature was that Classified Emergency Materia Medica(證類本草) and not writings specializing in cold damage are in use. In general, although CPC in terms of form is similar to CRSB, content creation predominantly depended on PHBP. More specifically; first, in terms of the existence of cold damage infection, arguments of PHBP and CRSB are maintained. Second, in terms of cold damage classification, although CRSB is followed, heat pathogen disease is classified separately developing PHBP as is. Third, in terms of method, as Book of Keep Healthy(南陽活人書) and CRSB compiled in later times are cited, it is deemed that arguments were raised to a certain extent regarding six-meridian syndrome differentiation(六經辨證). Fourth, although the majority of utilized materia medica among cold damage prescriptions utilize Materia Medica from the Countryside(鄕藥本草) in CPC and materia medica from Korean Peninsula, this is due to the desire for the compilation performance of CPC to be propagated to ordinary citizens and not the ruling class. CPC as the official medical book compiled in the early days of the Chosun period was greatly influenced by the Song(宋) Dynasty's medical books, PHBP and CRSB shows that cold damage medicine in the early Chosun Period indeed possesses the medical universality of East Asia. Furthermore, the features of published medical theory and prescriptions reveal the existence of the cold damage medical tradition of the Chosun period serving as clues for cold damage research tradition among Korea's medical history.

An Empirical Study on the Impact of the Perception of the Monitoring Function on Effective BPMS Adoption (모니터링 기능에 대한 인식이 효과적인 BPMS 도입에 미치는 영향)

  • Chae, Myung-Sin;Park, Jin-Suk;Lee, Byung-Tae
    • Asia pacific journal of information systems
    • /
    • v.17 no.3
    • /
    • pp.105-130
    • /
    • 2007
  • Recently, there is a substantial interest in implementing Business Process Management System(BPMS) among enterprises with the purpose of business process innovation. BPMS redesigns and coordinates business processes in terms of both automated steps and human involvement in order to maximize the value of both involved people and systems. The reason why BPMS is getting attention from top managers is that it has the possibility to optimize the business processes by cycling the process of modeling, execution, monitoring, evaluation, and redesigning work processes. Thus, it has created high expectations about not only productivity improvement but also business process innovation. However. having an innovative nature, which is used for process innovation, BPMS implementation has great potential to stir up employee resistance. The analysis and the discussion about the prevention of the resistance against IS(Information Systems) is important because IS change the way people work and also alter the power structure within the organization, in general. The purpose of this study is to investigate factors that have an impact on the effective adoption of BPMS at the enterprise level. To find out these factors, this study considers two characteristics of BPMS: First. BPMS shares some characteristics with other enterprise-wide IS such as ERP. Second, it has special BPMS-specific characteristics. Due to the lack of previous research on BPMS adoption, interviews were carried out with IT-consultants and CIOs who conducted BPMS projects previously to find out BPMS-specific features that would make BPMS unique when compared to other enterprise-wide IS. As a result, the monitoring function was chosen as the main BPMS-specific factor. Thus, this paper reviewed studies both on enterprise-wide IS adoptions, which applied Technology Acceptance Model (TAM) and secondly on computer based monitoring to find out factors that would influence the employees' perception on the monitoring function of BPMS. Based on the literature review, the study suggested three factors that would have an impact on the employee's perception of the monitoring function: fairness of enterprise evaluation system, fairness of the boss, and self-efficacy of their work. Three factors that would impact the enterprise-wide IS adoption were also set: the shared belief in the benefit of BPMS, training, and communication. Then, these factors were integrated with TAM. Structural equation modeling was used to test hypotheses, out factors that would impact the employees' perception on the monitoring function of BPMS. Based on the literature review the study suggested three factors that would have an impact on the employee's perception of the monitoring function: fairness of enterprise evaluation system, fairness of the boss, and self-efficacy of their work. Three factors that would impact the enterprise-wide IS adoption were also set: the shared belief in the benefit of BPMS, training, and communication. Then, these factors were integrated with TAM. Structural equation modeling was used to test hypotheses. The data analysis results showed that two among three monitoring function related factors - enterprise evaluation system and fairness of the boss - were significant. This implies that employees would worry less about the BPMS implementation as long as they perceive the monitoring results will be used fairly for their performance evaluation. However, employees' high self-efficacy on their job was not a significant factor in their perception of the usefulness of BPMS. This is related to cases that showed employees resisted against the information systems because they automated their works (Markus, 1983). One specific case was an electronic company, where the accounting department workers were requested to redefine their job because their working processes were automated due to BPMS implementation.

A Study about the Correlation between Information on Stock Message Boards and Stock Market Activity (온라인 주식게시판 정보와 주식시장 활동에 관한 상관관계 연구)

  • Kim, Hyun Mo;Yoon, Ho Young;Soh, Ry;Park, Jae Hong
    • Asia pacific journal of information systems
    • /
    • v.24 no.4
    • /
    • pp.559-575
    • /
    • 2014
  • Individual investors are increasingly flocking to message boards to seek, clarify, and exchange information. Businesses like Seekingalpha.com and business magazines like Fortune are evaluating, synthesizing, and reporting the comments made on message boards or blogs. In March of 2012, Yahoo! Finance Message Boards recorded 45 million unique visitors per month followed by AOL Money and Finance (19.8 million), and Google Finance (1.6 million) [McIntyre, 2012]. Previous studies in the finance literature suggest that online communities often provide more accurate information than analyst forecasts [Bagnoli et al., 1999; Clarkson et al., 2006]. Some studies empirically show that the volume of posts in online communities have a positive relationship with market activities (e.g., trading volumes) [Antweiler and Frank, 2004; Bagnoli et al., 1999; Das and Chen, 2007; Tumarkin and Whitelaw, 2001]. The findings indicate that information in online communities does impact investors' investment decisions and trading behaviors. However, research explicating the correlation between information on online communities and stock market activities (e.g., trading volume) is still evolving. Thus, it is important to ask whether a volume of posts on online communities influences trading volumes and whether trading volumes also influence these communities. Online stock message boards offer two different types of information, which can be explained using an economic and a psychological perspective. From a purely economic perspective, one would expect that stock message boards would have a beneficial effect, since they provide timely information at a much lower cost [Bagnoli et al., 1999; Clarkson et al., 2006; Birchler and Butler, 2007]. This indicates that information in stock message boards may provide valuable information investors can use to predict stock market activities and thus may use to make better investment decisions. On the other hand, psychological studies have shown that stock message boards may not necessarily make investors more informed. The related literature argues that confirmation bias causes investors to seek other investors with the same opinions on these stock message boards [Chen and Gu, 2009; Park et al., 2013]. For example, investors may want to share their painful investment experiences with others on stock message boards and are relieved to find they are not alone. In this case, the information on these stock message boards mainly reflects past experience or past information and not valuable and predictable information for market activities. This study thus investigates the two roles of stock message boards-providing valuable information to make future investment decisions or sharing past experiences that reflect mainly investors' painful or boastful stories. If stock message boards do provide valuable information for stock investment decisions, then investors will use this information and thereby influence stock market activities (e.g., trading volume). On the contrary, if investors made investment decisions and visit stock message boards later, they will mainly share their past experiences with others. In this case, past activities in the stock market will influence the stock message boards. These arguments indicate that there is a correlation between information posted on stock message boards and stock market activities. The previous literature has examined the impact of stock sentiments or the number of posts on stock market activities (e.g., trading volume, volatility, stock prices). However, the studies related to stock sentiments found it difficult to obtain significant results. It is not easy to identify useful information among the millions of posts, many of which can be just noise. As a result, the overall sentiments of stock message boards often carry little information for future stock movements [Das and Chen, 2001; Antweiler and Frank, 2004]. This study notes that as a dependent variable, trading volume is more reliable for capturing the effect of stock message board activities. The finance literature argues that trading volume is an indicator of stock price movements [Das et al., 2005; Das and Chen, 2007]. In this regard, this study investigates the correlation between a number of posts (information on stock message boards) and trading volume (stock market activity). We collected about 100,000 messages of 40 companies at KOSPI (Korea Composite Stock Price Index) from Paxnet, the most popular Korean online stock message board. The messages we collected were divided into in-trading and after-trading hours to examine the correlation between the numbers of posts and trading volumes in detail. Also we collected the volume of the stock of the 40 companies. The vector regression analysis and the granger causality test, 3SLS analysis were performed on our panel data sets. We found that the number of posts on online stock message boards is positively related to prior stock trade volume. Also, we found that the impact of the number of posts on stock trading volumes is not statistically significant. Also, we empirically showed the correlation between stock trading volumes and the number of posts on stock message boards. The results of this study contribute to the IS and finance literature in that we identified online stock message board's two roles. Also, this study suggests that stock trading managers should carefully monitor information on stock message boards to understand stock market activities in advance.

Effects of Transaction Characteristics on Distributive Justice and Purchase Intention in the Social Commerce (소셜커머스에서 거래의 특성이 분배적 정의와 거래 의도에 미치는 영향)

  • Bang, Youngsok;Lee, Dong-Joo
    • Asia pacific journal of information systems
    • /
    • v.23 no.2
    • /
    • pp.1-20
    • /
    • 2013
  • Social commerce has been gaining explosive popularity, with typical examples of the model such as Groupon and Level Up. Both local business owners and consumers can benefit from this new e-commerce model. Local business owners have a chance to access potential customers and promote their products in a way that could not have otherwise been easily possible, and consumers can enjoy discounted offerings. However, questions have been increasingly raised about the value and future of the social commerce model. A recent survey shows that about a third of 324 business owners who ran a daily-deal promotion in Groupon went behind. Furthermore, more than half of the surveyed merchants did not express enthusiasm about running the promotion again. The same goes for the case in Korea, where more than half of the surveyed clients reported no significant change or even decrease in profits compared to before the use of social commerce model. Why do local business owners fail to exploit the benefits from the promotions and advertisements through the social commerce model and to make profits? Without answering this question, the model would fall under suspicion and even its sustainability might be challenged. This study aims to look into problems in the current social commerce transactions and provide implications for the social commerce model, so that the model would get a foothold for next growth. Drawing on justice theory, this study develops theoretical arguments for the effects of transaction characteristics on consumers' distributive justice and purchase intention in the social commerce. Specifically, this study focuses on two characteristics of social commerce transactions-the discount rate and the purchase rate of products-and investigates their effects on consumers' perception of distributive justice for discounted transactions in the social commerce and their perception of distributive justice for regular-priced transactions. This study also examines the relationship between distributive justice and purchase intention. We conducted an online experiment and gathered data from 115 participants to test the hypotheses. Each participant was randomly assigned to one of nine manipulated scenarios of social commerce transactions, which were generated based on the combination of three levels of purchase rate (high, medium, and low) and three levels of discount rate (high, medium, and low). We conducted MANOVA and post-hoc ANOVA to test hypotheses about the relationships between the transaction characteristics (purchase rate and discount rate) and distributive justice for each of the discounted transaction and the regular-priced transaction. We also employed a PLS analysis to test relations between distributive justice and purchase intentions. Analysis results show that a higher discount rate increases distributive justice for the discounted transaction but decreases distributive justice for the regular-priced transaction. This, coupled with the result that distributive justice for each type of transaction has a positive effect on the corresponding purchase intention, implies that a large discount in the social commerce may be helpful for attracting consumers, but harmful to the business after the promotion. However, further examination reveals curvilinear effects of the discount rate on both types of distributive justice. Specifically, we find distributive justice for the discounted transaction increases concavely as the discount rate increases while distributive justice for the regular-priced transaction decreases concavely with the dscount rate. This implies that there exists an appropriate discount rate which could promote the discounted transaction while not hurting future business of regular-priced transactions. Next, the purchase rate is found to be a critical factor that facilitates the regular-priced transaction. It has a convexly positive influence on distributive justice for the transaction. Therefore, an increase of the rate beyond some threshold would lead to a substantial level of distributive justice for the regular-priced transaction, threrby boosting future transactions. This implies that social commerce firms and sellers should employ various non-price stimuli to promote the purchase rate. Finally, we find no significant relationship between the purchase rate and distributive justice for the discounted transaction. Based on the above results, we provide several implications with future research directions.

  • PDF

Ecological Health Assessment of Dongjin River Based on Chemical Measurement and Fish Assemblage Analysis. (동진강의 이.화학적 수질 및 서식지 분석을 통한 어류 생태영향 평가)

  • Kim, Yu-Pyo;Lee, Eui-Haeng;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
    • /
    • v.42 no.2
    • /
    • pp.183-191
    • /
    • 2009
  • This study was to evaluate ecological health of Dongjin River in October 2007. The ecological health assessments was based on the Index of Biological Integrity (IBI), Qualitative Habitat Evaluation Index (QHEI), and water chemistry. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. We also analyzed spatial patterns of chemical water quality over the period of 2005${\sim}$2008, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. In Dongjin River, values of IBI averaged 19 (n=3), which is judged as a "Fair" condition after the criteria of Barbour et al. (1999). There was a distinct spatial variation. IBI score at Site 1 was estimated as 28, indicating a "Good" condition whereas, IBI at Site 2 and Site 3 were as 18 and 12, indicating "Fair" and "Poor" condition, respectively. Habitat analysis showed that QHEI values in the river averaged 117 (n=3), indicating a "Fair${\sim}$Good" condition after the criteria of Barbour et al. (1999). Values of BOD and COD averaged 2.3 mg $L^{-1}$ (scope: 0.1${\sim}$8.9 mg $L^{-1}$) and 5.5 mg $L^{-1}$ (scope: 1.8${\sim}$12.6 mg $L^{-1}$), respectively during the study. Total nitrogen (TN) and total phosphorus (TP) averaged 2.7mg $L^{-1}$ and 0.127mg $L^{-1}$, respectively, and the nutrients showed large longitudinal gradients between the upper and lower reach. Overall, dataset of IBI, QHEI, and water chemistry showed that river health was a gradual decline at upstream to downstream. So, Dongjin River should be protected from habitat disturbance and chemical pollutions.