Dynamic Analysis of the Effect of Network Externality in Vertically Differentiated Market Hyung-Rae Cho․Minho Rhee † Dept. of Industrial Systems Engineering/ERI, Gyeongsang National University

조형래(Hyung-Rae Cho):이민호(Minho Rhee) 한국산업경영시스템학회 2019 한국산업경영시스템학회지 Vol.42 No.2

Network externalities are essentially dynamic in that the value consumers feel about a product is affected by the size of the existing customer base that uses that product. However, existing studies on network externalities analyzed the effects of network externalities in a static way, not dynamic. In this study, unlike previous studies, the impact of network externalities on price competition in a vertically differentiated market is dynamically analyzed. To this end, a two-period duopoly game model was used to reflect the dynamic aspects of network externalities. Based on the game model, the Nash equilibria for price, sales volume, and revenue were derived and numerically analyzed. The results can be summarized as follows. First, if high-end product has strong market power, the high-end product vendor takes almost all benefits of the network externality. Second, when high-end product has strong market power, the low-end product will take over most of the initial sales volume increase. Third, when market power of high-end product is not strong, it can be seen that the effects of network externalities on the high and low-end products are generally proportional to the difference in quality. Lastly, if there exists a strong network externality, it is shown that the presence of low-end product can be more profitable for high-end product vendor. In other words, high-end product vendor has incentive to disclose some technologies for the market entrance of low-end product, even if it has exclusive rights to the technologies. In that case, however, it is shown that the difference in quality should be maintained significantly.

기업가지향성과 조직문화가 기업성과에 미치는 영향에 관한 연구

조형래(Jo, Hyung-Rae) 글로벌경영학회 2012 글로벌경영학회지 Vol.9 No.4

조직성과에 관한 오랜 연구에서는 그에 영향을 주는 요인들을 기업이 보유하고 있는 자원역량, 환경요 인, 전략적 구성, 경영관리 특성 등으로 보고 그러한 요인들을 중심으로 주요한 분석들을 수행해 왔다. 본 연구에서는 기업들의 성과에 영향을 줄 것으로 기대되는 조직문화적인 변수들을 중심으로 분석하였 다. 이를 통해 조직의 더 근원을 이루는 요소들을 분석함으로써 기업들에게 다른 시사점을 전해 줄 수있을 것으로 기대할 수 있다. 구체적으로 기업성과에 영향을 주는 조직문화의 요인으로서 기업가지향성, 참여적 문화, 사명감 문화 등을 고려하였다. 이론적 고찰의 결과 기업가지향성은 신제품개발에의 성과를 비롯한 여러 기업성과에 영향을 주는 요인으로 나타났고 참여적 문화, 사명감 문화도 기업의 여러 성과에 영향을 주는 요인으로 분석되었다. 따라서 연구의 모형과 가설은 이들 변수들이 기업성과에 어떻게 영향을 주는가 라는 점에 초점을 맞추어 수립되었다. 실증분석을 위해 89개의 기업체 자료들이 수집되 었다. 요인분석 결과 기업가지향성, 참여적 문화, 전략적 초점, 비전 공유의 4가지 변수들이 최종적인 독립변수로 선정되었고 기업성과는 재무적 성과, 비재무적성과, 전반적 성과의 세 가지로 구성되었다. 가설검증을 위한 회귀분석 결과 전략적 초점은 모든 종속변수에 중요하게 영향을 주는 변수로 나타났다. 기업가지향성은 비재무적 성과에 영향을 주는 것으로 나타났다. 조직문화 차원의 변수들이 고려되었으 므로 향후 기업들에서 얻을 수 있는 시사점들이 그에 따라 제시되었다. 즉 향후 기업에서 전략적 초점을 가지도록 하는 명시적인 경영 실무 뿐만 아니라 이러한 점들이 기업의 하나의 저변을 이루는 문화로서 정착될 수 있는 노력이 필요하다는 점을 기업들에게 말해 주고 있다. Until now most research on the performance of firms has dealt with management characteristics, strategic formulation, and firm capabilities as major influential variables. This study analyze the organizational cultural variables mainly which are expected to influence the performance of firms. We may anticipate to give some implications to companies through the analysis of more fundamental elements of an organization. Specifically entrepreneurial orientation, involvement culture, mission culture are considered as cultural variables. By theoretical review, we found that entrepreneurial orientation had influenced various firm performance including new product development performance as well as involvement culture and mission culture. Accordingly, we established research model and hypotheses focusing on how these variables influences firm performance. For empirical analysis, 89 samples of firms were gathered. By the result of factor analysis, we selected 4 main independent variables of entrepreneurial orientation, involvement culture, strategic focus, share of vision and 3 main dependent variables of financial performance, non-financial performance, comprehensive performance. After we implemented the regression analysis for the hypotheses testing, we found that strategic focus have significant influence on all of the performace indicators and that entrepreneurial orientation have significant influence on the non-financial performance. As we adopted variables of organizational cultural variables as main research variables, the implications of this research suggest that company should stress not only on the explicit management practices related to the strategic focus but also on the efforts which make these aspects to be set up as the culture underlying the organization.

代替的 情報시스템의 評價에 관한 考察

李炯來 德成女子大學校 1988 德成女大論文集 Vol.17 No.-

The impact of information economics on accounting has been increased since 1970's. e, g. the choice among the financial reporting systems and the information choice for management decision making agency problem. There creteria by which competing information systems can be compared, independent of the payoff functions and the probability distribution function of users has been proposed in the information economics research. ; fineness, sufficiency and garbling. This review explains the relationships among fineness, sufficiency and garbling, the value of information.

Carbofuran 土壤混入處理의 水稻害蟲 防除效果 및 水稻生育에 미치는 影響

朴亨萬,朴重秀,崔承允,李炯來 서울大學校 農科大學 1981 서울대농학연구지 Vol.6 No.1

In 1980, a field experiment was conducted to evaluate the effects of soil-incorporated Carbofuran (Furadan 3G) on some rice insect pests and on the growth of rice plants of the variety Milyang-23, which is one of the Korean leading varieties. The effects were compared with those of the conventional broadcast of Carbofuran and Diazinon as local standard method. The results obtained were as follows: (1) The soil incorporation of Carbofuran dramatically suppressed the plant damages of the rice stem maggots (Chlorops oryzae and Hyderellia sasakii) and thrips (Baliothips biformis) at tillering stage of the rice; plant damages observed were 0.5%(1.2 a.i. kg/ha) and 0.6%(1.8 a.i. kg/ha) for the rice stem maggots, and 1.3%(1.2 a.i. kg/ha) and no damage(1.8 a.i. kg/ha) for thrips while with broadcast of Carbofuran there were 65.9%(1.2 a.i. kg/ha) and 42.4%(1.8% a.i. kg/ha) for ricestem maggots, and for the thrips, 60.6%, 36.0% with Carvofuran baoadcast, and 83.5%, 90.7% with Diazinon treatment, and 97.8% for the untreated check.(2) Soil incorporation and broadcast of Carbofuran were significantly effective for the control of brown planthoppers (Nilaparvata lugens) and the white-backed planthoppers (Sogatella furcifera), and the conventional broadcast of Diazinon was still unsatisfactory for controlling the brown planthoppers. (3) on 38th day after transplanting, the number of tillers per hill and plant height in the soil incoporation of Carboruran revealed the significant increases over those of the Carbofuran and Diazinon brodcasts and the check; with number of tillers per hill 23.0 for 1.2 a.i. kg/ha and 25.7 for 1.8 a.i. kg/ha with number of tillers per hill 23.0 for 1.2 a.i. kg/ha and 25.7 for 1.8 a.i. kg/ha with Carbofuran soil incorporation, while they were for 20.1, 22.1, with respective doses of the broadcasted Carbofuran they were 19.1 for the broadcased Diazinon, and 18.5 for the check, on the 82nd day after transplanting, root development of rice plants grown on the Carbofuran soil incorporated sites also revealed a significant increase over the broadcasting treatments and the check in the number and length of roots.(4) Even under the unusual low-temperature conditions during 1980 in Korea, Carvofuran soil incorporation greatly promoted the heading of rice plants and consequently resulted in significant shortening of the heading time as compared to those of Carbofuran and Diazinon broadasts and the check. In addition, soil incorporation of Cabofuran resulted in much better heading status(65 to 70% in completed heading) than broadcast(35 to 37% in Carbofuran broadcast and 20% in Diazinon broadcast) and the untereated check(30%). (5) The mexmium growth promotion of rice plants was observed from the rate of 1.8 a.i. kg/ha of the Carbofuran soil incorporation in plant height (90.0cm), stem height(78.6cm), length of uppermost internodes(24.7cm), and root weight(5.0g/hill in dry base) over the untreated check(81.9cm in plant height, 62.9cm in stem height, 19.3cm in uppermost intermodes and 3.6g in root weight) and other insecticide treated plots. However, there was no singnificant difference in panicle length among the treatments. (6) The number of panicles per hill, number of grains per panicle and 1000-grain weight showed that Carbofural soil incorporation significantly increased those yield components as compared to the broadcast and the untreated check. Of the treatments, Carbofuran soin incorporation registered significantly higher grain yields (2,460kg/ha from 1.2 a.i. kg/ha and 2,244kg/ha from 1.8 a.i. kg/ha treatments) than Carbofuran broadcest (1,005kg/ha from 1.2 a.i. kg/ha and 1,185kg/ha from 1.8 a.i. kg/ha treatments), Diazinon broadcast(63kg/ha), and the check(849kg/ha). Showing the low yield potential of the test variety seemed to be cold-damage from unusual weather conditions in 1980. (7) Analysis of essential macro-and micro-element contents in rice plants on the 122nd day after transplanting showed more k, Cu, Mn and Zn contents in the plants treated by soil incorporation of Carbofuran than those in the untreated check, while N and Fe were lower in the plants treated by Carbofuran than those in the untreated check, while N and Fe were lower in the plants treated by Carbofuran soil incorporation. Amounts of K and Zn were much greater in Carbofuran soil incorporation than in Carbofuran broadcast, and N and P were greatly lower in the plants by Carbofuran soil incorporation. (8) in conclusion, the result obtained in this study would provide some real evidences that Carbofuran incoporated with the paddy soils could be a new insecticidal application method of the maximization of rice yield through the dramatical suppressin of the plant damages of insect pests; the rice leaf stem maggots, thrips, and planthoppers, and great growth stimulation(increasing the root development, the effective tillers, panicles, etc.) of rice plants.

하악구치부 보철공간을 위한 상악구치부의 분절골절단 및 상방 정위

김명래,김충,김형섭 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.4

Purpose : This is to review the cases of posterior maxillary segmental osteotomies to regain the interarch spaces for dental implants in the posterior mandible. Materials & Methods: Seven patients who presented with alveolar extrusion of upper posterior molars underwent segmental osteotomies by single-stage Kufner's buccal approach under the intravenous sedation and local anesthesia. The posterior maxillary cento-alveolar segments were repositioned upward using pre-fabricated palato-occlusal resin splints and immobilized with osteosynthesis microplates and screws Dental implants were installated simultaneously. The regained spaces, tooth vitality, periodontal healing, relapse, tenderness on function, and complications including maxillary sinus involvements were evaluated periodically for over one year after the surgeries. Results : The single-tage procedures were completed within 80 minutes without any surgical complications. The posterior maxillary segments were repositioned upward to regain the interarch spaces ranging from 2.5 to 5.5mm. All teeth involved in the procedures keep their vitalities. The repositioned segments were maintained showing neither evidence of periodontal break-down nor tenderness to function, One patient whose segments had not been immobilized by osteosynthesis plate resulted in 2mm down-ward relapse in post-operative 8 months. A case of postoperative nasal bleeding from the posterior-lateral wall resulted in oroantral fistula and chronic maxillary sinusitis later. Conclusion : The extruded dento-alveolar segments of the posterior maxilla were repositioned properly by Kufner's one-stage segmental osteotomies. One microplate can be of help to keep the position until the osseous healing enough to support the masticatory force.

忠北地域 벼멸구 系統의 殺蟲劑 低抗性에 關한 硏究

李炯來,金正和 충북대학교 농업과학기술연구소 1991 農業科學硏究 Vol.9 No.1

The strains of brown planthopper(BPH), Nilaparvata lugens Stal, which collected on paddy field in Chungbuk province during the late of September to early of October in 1990 were studied to investigates of insecticide resistance and biochemical characteristic. The results are summarized as follows ; 1.In comparison of LD50(㎍/g) by the several insecticides against the collected strains of BPH, the fenthion showed 22.40 at Seoksung strain of BPH and the BPMC showed 6.90 at Cheongju strain of BPH. While, propoxur, carbaryl and carbofuran showed no big differance of the collected strains. 2.In resistant levels of the insecticides against the collected strains of BPH compared with the LD50 level(㎍/g) of susceptible strain of BPH(S-Lab), the BPMC and the propoxur showed highly resistant levels for 7.04 and 3.4 times, respectively. 3.Comparisons of LC50 (ppm) against the collected BPH: with different bioassay methods showed the susceptible trend on spray method > topical microapplication method > dipping method and the trend was with the results of LD50 levels on tested strains of BPH. 4.In comparison of esterase activity against the collected strains of BPH as compared with the susceptible strain(S- Lab) , the activity of β-band showed higher than the results of α-band and the activity of resistant strains in collected BPH showed more higher than susceptible strains of the collected BPH.

에폭시수지를 이용한 콘크리트 보의 균열 보수효과에 관한 연구

李炯來,柳熙仲 호남대학교 산업기술연구소 2000 산업기술연구논문집 Vol.8 No.-

최근 콘크리트 구조물의 균열보수에 가장 많이 사용되는 에폭시수지는 접착성과 화학성이 우수하여 효과적인 균열 보수재료로 인식되어 왔으며, 이에 대한 연구가 최근 진행되고 있지만 에폭시수지의 균열보수에 대한 엄격한 규준이 없는 현실이다. 따라서 본 연구에서는 콘크리트 구조물의 부재에 가장 많이 적용되는 압축강도 150kg/cm2, 250kg/cm2, 350 kg/cm2 의 콘크리트 보에 가력장치를 이용하여 4, 5, 7 ton의 하중을 재하 함으로써 시험체에 0.2∼0.3mm폭의 균열을 발생시킨 후, 국내에서 가장 많이 사용되고 있는 H사의 에폭시 수지를 선정하여 주제와 경화제의 혼합율을 3 : 1, 5 : 1, 7 : 1의 비율로 달리하여 균열을 저압저속주입공법으로 보수한 후, 파괴실험을 실시하여 균열에 대한 보수성능을 비교, 분석하였다. 본 연구 결과를 요약하면 압축강도의 증가에 따른 보수성능은 증가하지 않았으며 또한 큰 차이가 없었다. 그리고 혼합비율에 따른 보수성능은 주제의 증가에 따라 증가하지 않았으며 주제와 경화제의 비율이 5 : 1인 경우가 보수효과가 가장 크다는 것을 알 수 있었다. 그러므로 보수효과는 보수체의 압축강도보다는 혼합비율이 보수성능에 더 큰 영향을 미친다고 판단되며, 실제 현장에서 에폭시수지를 이용하여 균열을 보수할 경우, 보수성능을 높이기 위해서 수지재료의 특성에 따른 최적의 혼합비율을 채택하여야 하며, 또한 엄격한 계량에 의하여 혼합한 후, 보수를 실시하는 것이 매우 중요하다고 판단된다. Since epoxy resin which has been widely used to rehabilitate cracks of concrete structures has good adhesion and chemical properly, it is considered as effective repairing material. There is no strict criterion for crack repair of epoxy resin although a lot of studies have been performed recently. In this study concrete beams whose compressive strengths are 150 kg/cm2, 250 kg/cm2, 350 kg/cm2 are loaded about 4, 5, 7 ton and the crack of 0.2∼0.3mm width is made. Epoxy resin is chosen as the product of H company widely used in Korea. The mixture ratio of resin and hardener has three cases such as 3:1, 5:1 and 7:1 After crack is repaired using inject grouting, fracture test is performed and the rehabilitation efficiency for crack is analyzed. As compressive strength increases, rehabilitation efficiency does not increase. Also there is no big difference. Although the resin increases, rehabilitation efficiency for the mixture ratio does not increase. The mixture ratio of resin and hardener, 5:1, has the best rehabilitation efficiency Therefore it is concluded that the mixture ratio rather than compressive strength has an effect on rehabilitation efficiency. If crack is repaired using epoxy resin in field, the optimum mixture ratio should be chosen to increase the rehabilitation efficiency. And the rehabilitation should be performed after being mixed by the accurate weighing.

벤처산업의 활성화를 위한 인프라의 개선 방안

趙瀅來 한국중소기업학회 1998 기업가정신과 벤처연구 Vol.1 No.2

This paper studies reform measures of the infrastructure which can vitalize the current venture industry. In so doing, the following procedures have been undertaken : (1) developing the analytical model for the analysis of the infrastructure of venture industry; (2) identifying the demand factor of the infrastructure by reviewing the literature of the influential factors about new venture performance; (3) assessing the supply side of the infrastructure by investigating the current status; (4) identifying the problems of the infrastructure by comparing the demand and supply aspects of it; (5) deriving the alternative reform measures to solve those problems. In proposing reform measures, reform measures at macro level were derived first and then specific methods based on the macroscopic reform measures were investigated. Macroscopic reform measures are as follows : (1) introduction of free competition by removing various regulations and limitations (2) understanding of the real system of venture industry(mechanism and phenomenon) (3) securing specialty by retaining focus in the groping for institutions and methods applying to venture industry (4) emphasis of soft-technological aspects like management technique and/or information in addition to money and personnel.

벼 멸구에 對한 Carbofuran의 殺蟲效果에 미치는 環境要因의 影響 (Ⅰ) 土性, 有機物, pH.溫度 : Effect of Environmental Factors on the Biological Toxicity of Carbofuran against the Brown Planthopper(Nilaparvata lugens STAL) Ⅰ.Soil Texture, Organic Matters, pH and Temperature

李炯來,李海根 충북대학교 농업과학기술연구소 1987 農業科學硏究 Vol.5 No.1

A study was conducted to determine the effects of environmental factors which were soil texture, organic matter, pH and temperature on the biological toxicity against the brown planthopper BPH, (Nilaparvata lugens STAL) when carbofuran 3% granule was applied in artificial controlled pots. The experimental results are shown as follows; 1.Soil texture did not affect the biological toxicity of carbofuran on the BPH until 7 days after treatment (DAT) of carbofuran 3%G, but thereafter loam type soil showed the higher efficacy than those of sandy loam and clay loam. 2.The lower contents of organic matters in soil, the higher mortality of the BPH. 3.Soil pH did not affect the mortality of the BPH until 4 DAT, but !he lower pH in soils, the higher mortality from 14 DAT. 4.When sprayed with BPMC, MIPC, carbaryl and diazinon, the effects of temperature on the mortality of the BPH showed that the higher temperature, the higher mortality at 1 DAT, but the reverse was the case at 4 DAT. In case of application with carbofuran and diazion granules, the mortality of carbofuran were decreased at 20℃ and that of diazinon at 20-25℃.

月岳山 國立公園의 昆忠分布相(第1報)

李炯來,金正和 충북대학교 농업과학기술연구소 1988 農業科學硏究 Vol.6 No.1

A survey of insect fauna on the national park of Mt. Woalack, was conducted the 2 times 20~23th June and 2nd Octorber in 1987. The identification of collected insects was recorded 173 species in 70 families and 13 orders. The 20 species were unrecorded among them in our country until now. Up to date, total numbers of identification on Mt. Woalack recorded 265 species in 83 families and 13 orders.