• Title/Summary/Keyword: marginal effects

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The Effects of Panax gineseng on the Side Effects of Cyclophosphamide to the Spleen in the Rat (인삼추출물이 Cyclophosphamide에 손상된 흰쥐 비장조직의 회복에 미치는 영향)

  • Kim, Jin-Taek;Kim, Dong-Hoan;Ann, Sang-Hyun;Yoon, Sik
    • The Journal of Dong Guk Oriental Medicine
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    • v.2 no.1
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    • pp.177-182
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    • 1993
  • This study were performed for the effects of Panax ginseng on the side effect of Cyclophosphamide to splenic tissue in the Rats. The experimental animals were divided into control group, test group by the way of the method treatment of the drug. Each group was sacrificed and stained in accordance with the schedule and observed under light microscope. The results of this study were as follows : 1. After the ginseng extract administration rat's weight and volume were similarly increased than normal and control group. 2. The decrease of the numbers of the splenic tissue after treatment of cyclophosphamide(CP) were recovered with prescription of the ginseng extract; the decrease of white pulp, red pulp, marginal zone were recovered. 3. Increased macrophage in red pulp of splenic tissue with administration of CP were disapeared after treatment of ginseng extract.

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The Effects of Food Delivery and Single-Person Household on Municipal Solid Waste Generation: Focus on the COVID-19 Period (음식 배달 및 1인 가구가 생활 폐기물 발생량에 미치는 영향: 코로나-19 시기를 중심으로)

  • Kim, Hyung-Gun
    • Asia-Pacific Journal of Business
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    • v.13 no.3
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    • pp.389-400
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    • 2022
  • Purpose - This study empirically analyzes the effects of food delivery service use frequency and the proportion of single-person households on the generation of MSW (Municipal Solid Waste). Additionally, the study analyzes MSW increase during the COVID-19 period. Design/methodology/approach - The study uses annual information on MSW and related characteristics of 228 Si, Gun, and Gu, which are administrative districts of Korea, from 2015 to 2020. Panel fixed effect model is employed for estimations. Findings - The study finds that food delivery and single-person household have significant effects only on recyclable and standard garbage bag MSW, respectively, not on all produce types of MSW. Additionally, it is estimated that, during the COVID-19 period, the increasing effect of food delivery is intensified while single-person households diminish its increasing effect. Lastly, the study confirms that the marginal effect on the increasing effect of MSW generation by the number of household members. Research implications or Originality - The estimated results are expected to provide useful information for the related policies. In particular, it is necessary to focus more on recyclable MSW concerning the developing delivery culture, and regarding changes in the family structure, focus more on the number of household members than single-person households.

Localized Knowledge Spillovers and Organizational Capabilities: Evidence from the Canadian Manufacturing Sector

  • Joung-Yeo No
    • Journal of Korea Trade
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    • v.27 no.5
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    • pp.91-112
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    • 2023
  • Purpose - This study empirically investigates how the effects of localized knowledge spillovers on technology adoption are conditional on the organizational capabilities of potential adopters. Design/methodology - The empirical model utilized in this study examines how the presence of prior adopters of advanced manufacturing technologies affects a plant's technology adoption decision differently based on its organizational capabilities, measured by plant size and plant status (single-plant firm vs. multi-plant firm). Moreover, this study investigates how the scope of knowledge spillovers from prior adopters, both in terms of geographical and functional proximities, differ for plants with different organizational capabilities. Findings - The main findings of this study are as follows: 1. Although plants with lower organizational capabilities are less likely to adopt advanced technologies, such plants receive greater marginal benefits from knowledge spillovers from prior adopters in their region. 2. Plants with greater organizational capabilities can benefit from knowledge spillovers from a wider set of prior adopters. In other words, while plants with lower organizational capabilities tend to benefit from knowledge spillovers from "similar" and "local" adopters, plants with greater organizational capabilities can also benefit from knowledge spillovers from "not-too-similar" or are geographically distant prior adopters. Originality/value - While existing studies mainly focus on the effects of the various kinds of regional agglomeration, few studies investigate localized knowledge spillovers in technology adoption. Moreover, no prior studies have explored how the effects of knowledge spillovers on technology adoption depend on a plant's organizational capabilities and how the scope of knowledge spillovers differs for plants with different organizational capabilities. This study is the first to empirically investigate this topic.

Value Evaluation Model for Korean Professional Baseball Players (한국프로야구선수의 가치평가모형)

  • Oh, Taeyeon;Lee, Young Hoon
    • Journal of Labour Economics
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    • v.39 no.2
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    • pp.113-139
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    • 2016
  • The purpose of this study is to establish evaluation model that can explain marginal effects of baseball players of Korean Baseball Organization (KBO) on their team winnings in terms of productivity. We proposed econometric model with using variables that are provided from official homepage of KBO to overcome the complexity of mainly used productivity index: wins above replacement (WAR). Also, compare to the previous studies such as Scully(1974) or Krautmann(1999) that using limited indices of baseball stats, this study included 61 indices that are provided from official homepage of KBO. We estimated regression based WAR(RBWAR) by conducting panel regression with each team's statistics data of 2002 to 2014. As a results, RBWAR shows 0.869 correlation coefficient for batters and 0.882 for pitchers with WAR in 2014 that can be concluded that two indices shows similar results. From the results of estimation, we analyze the relationship between productivity and actual contract of free agent players in 2015 and it showed that teams have contracted reasonably.

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Study on the resistance of various herbaceous plants to the effect of heavy metals-responses of plants to soil treated with cadmium and lead- (草本植物의 重金屬 抵抗性에 關한 硏究 - Cadmium, Lead 處理 土壤에 의한 反應 -)

  • Kim, Byung-Woo;Park, Jong-Sun
    • The Korean Journal of Ecology
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    • v.15 no.4
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    • pp.433-449
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    • 1992
  • Three horticultural herbaceous plants and a natural herbaceous plant were tested to determine the growth responses, biomass and uptake of cadmium(cd), lead(pb) by application of cd and pb soil treatment in pot culture. The ecological effects on the growth of the plants were investigated to determine the tolerance for the heavy metal pollutants cd and pb. the marginal concentrain of cd treatment on the growth of the each plant was below the 1, 000 ppm treatment of cd. The marginal concentration of pb treatment was below the 1, 000ppm treatment of pb in cultivation of salvia splendens ker., celosia cristata l. and below the 3, 000ppm treatment of pb in cultivation of portulaca grandiflora hook., sedum saramentosum bunge. the resistance for cd of sedum saramentosum bunge, celosia criastata l., portulaca grandiflora hook. and salvia splendens ker. was in the listed order. The resistence for pb was in order of sedum saramentosum bunge, portulaca grandiflora hook. Salvia splendens ker.and celosia criastata l.stems. The flowering of portulaca grandiflora hook. was sustained in the pb 1, 000ppm treated group only. The higher the concentration of pb in the soil cultivated the plants was, the less the content of leaf chlorophy11 in each plant was. The number of stomata per unit leaf area was the highest in salvia splendens ker. and in order of celosia l., sedum saramentosum bunge., portulaca grandiflora hook., the higher the cd and pb concentration of cd and pb treatment was, the more the concent of cd and pb in the part of each plant increased. the content of cd and pb in the stems of salvia spiendens ker. was the highest in the 1, 000ppm-treated ground and in order of the roots, the leaves and the flowers.

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Estimation of CO2 Abatement Cost Considering Allocative Inefficiency of Inputs for the Korean Steel Industry: A Cost Function Approach (국내 철강업의 생산요소 간 비효율적 배분을 고려한 CO2 저감비용 산정 및 분석: 비용함수접근법)

  • Lee, Myunghun
    • Environmental and Resource Economics Review
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    • v.23 no.3
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    • pp.453-472
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    • 2014
  • Analyzing the effects of carbon emissions trading, which is scheduled to be introduced in Korea in 2015, requires an accurate assessment of $CO_2$ abatement costs by both industries and firms. Firms faced with regulatory constraints are unlikely to minimize their production costs due to rising production costs caused by allocative inefficiency of inputs. The use of a distance function would results in underestimation of $CO_2$ abatement costs, because it fails to capture the allocative distortion costs. Recognizing the disadvantage of the previous approach, first, this paper tests for allocative efficiency of input for the Korean steel industry over the period 1990-2010, then derives the marginal $CO_2$ abatement costs by applying a cost function approach. The hypothesis of allocative efficiency in inputs is rejected and the steel industry pays an annual average cost of 92,000 won in removing an additional ton of $CO_2$ over the sample period.

Estimating the Contribution of Industrial Water on Output and Price Elasticities in Manufacture (제조업 생산에 대한 공업용수의 한계생산가치와 가격탄력성 연구)

  • Min, DongKi
    • Environmental and Resource Economics Review
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    • v.15 no.5
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    • pp.961-974
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    • 2006
  • This paper estimates output and price elasticities of the industrial water in order to provide the government with tools that help make educated decisions with regard with the water provision policies rendering the latter more efficient. The estimated output elasticity produces useful insights on the role of industrial water as an input into the production process while the estimate of price elasticity enablesus to forecast the effects of various water pricing policies. This paper employs the marginal productivity method in order to estimate the abovementioned elasticities. The magnitude of the estimated output elasticity imply that the value of industrial water is much higher than its average price while the price elasticity estimate suggests that the water pricing policy can be an effective tool of controlling the demand for industrial water.

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Evaluation of Economic Feasibility of Power Generation System using Waste Woody Biomass in a CFBC Plant (순환유동층연소로에서 폐목질계 바이오매스를 이용한 발전 시스템의 경제성 평가)

  • Kim, Sung-June;Nam, Kyung-Soo;Lee, Jae-Sup;Seo, Seong-Seok;Lee, Kyeong-Ho;Yoo, Kyung-Seun
    • Korean Chemical Engineering Research
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    • v.48 no.1
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    • pp.39-44
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    • 2010
  • Economic feasibility of power generation system using waste woody biomass in a circulating fluidized bed combustor has been investigated. Effects of important variables such as capital investment, cost of waste wood, certified emission reduction(CER), system marginal price(SMP) on the benefit of business have been analyzed. Internal rate of return(IRR) was predicted as 16.67%, which implicates the business is promising based on the assumptions such as SMP of 99 Won/kWh, capital cost of 10.65 billion won, and complimentary providing of waste wood. Major factors affecting the benefit of business were as follows; system marginal price, operational rate, capital investment, expenditure of waste wood, certified emission reduction. In addition, it must be necessary to consider CHP power plant providing steam as one of the means to diversify sales network, for the management of the business risk.

Seasonal Characteristics of Sea Surface Winds and Significant Wave Heights Observed Marine Meterological Buoys and Lighthouse AWSs near the Korean Peninsula (한반도 주변해역의 기상부이와 등표에서 관측된 계절별 해상풍과 유의파고 특성)

  • Kang, Yoon-Hee;Seuk, Hyun-Bae;Bang, Jin-Hee;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.24 no.3
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    • pp.291-302
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    • 2015
  • The seasonal variations of sea surface winds and significant wave heights were investigated using the data observed from the marine meteorological buoys (nine stations) and Automatic Weather Stations (AWSs) in lighthouse (nine stations) around the Korean Peninsula during 2010~2012. In summer, the prevailing sea surface winds over the East/West Sea and the South Sea were northerly/southerly and easterly/westerly winds due to both of southeast monsoon and the shape of Korean Peninsula. On the other hand, the strong northerly winds has been observed at most stations near Korean marginal seas under northwest monsoon in winter. However, the sea surface winds at some stations (e.g. Galmaeyeo, Haesuseo in the West Sea) have different characteristics due to topographic effects such as island or coastal line. The significant wave heights are the highest in winter and the lowest in summer at most stations. In case of some lighthouse AWSs surrounded by islands (e.g. Haesuseo, Seosudo) or close to coast (e.g. Gangan, Jigwido), very low significant wave heights (below 0.5 m) with low correlations between sea surface wind speeds and significant wave heights were observed.

Evaluation of the marginal and internal fit of a single crown fabricated based on a three-dimensional printed model

  • Jang, Yeon;Sim, Ji-Young;Park, Jong-Kyoung;Kim, Woong-Chul;Kim, Hae-Young;Kim, Ji-Hwan
    • The Journal of Advanced Prosthodontics
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    • v.10 no.5
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    • pp.367-373
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    • 2018
  • PURPOSE. To evaluate the fit of a crown produced based on a 3D printed model and to investigate its clinical applicability. MATERIALS AND METHODS. A master die was fabricated with epoxy. Stone dies were fabricated from conventional impressions (Conventional stone die group: CS, n=10). Digital virtual dies were fabricated by making digital impressions (Digital Virtual die group: VD, n=10). 3D data obtained from the digital impression was used to fabricate 3D printed models (DLP die group: DD, n=10, PolyJet die group: PD, n=10). A total of 40 crowns were fabricated with a milling machine, based on CS, VD, DD and PD. The inner surface of all crowns was superimposed with the master die files by the "Best-fit alignment" method using the analysis software. One-way and 2-way ANOVA were performed to identify significant differences among the groups and areas and their interactive effects (${\alpha}=.05$). Tukey's HSD was used for post-hoc analysis. RESULTS. One-way ANOVA results revealed a significantly higher RMS value in the 3D printed models (DD and PD) than in the CS and DV. The RMS values of PD were the largest among the four groups. Statistically significant differences among groups (P<.001) and between areas (P<.001) were further revealed by 2-way ANOVA. CONCLUSION. Although the fit of crowns fabricated based on the 3D printed models (DD and PD) was inferior to that of crowns prepared with CS and DV, the values of all four groups were within the clinically acceptable range (<$120{\mu}m$).