• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
• /
• pp.50-50
• /
• 2008

ZnO has been extensively studied for optoelectronic applications such as blue and ultraviolet (UV) light emitters and detectors, because it has a wide band gap (3.37 eV) anda large exciton binding energy of ~60 meV over GaN (~26 meV). However, the fabrication of the light emitting devices using ZnO homojunctions is suffered from the lack of reproducibility of the p-type ZnO with high hall concentration and mobility. Thus, the ZnO-based p-n heterojunction light emitting diode (LED) using p-Si and p-GaN would be expected to exhibit stable device performance compared to the homojunction LED. The n-ZnO/p-GaN heterostructure is a good candidate for ZnO-based heterojunction LEDs because of their similar physical properties and the reproducibleavailability of p-type GaN. Especially, the reduced lattice mismatch (~1.8 %) and similar crystal structure result in the advantage of acquiring high performance LED devices with low defect density. However, the electroluminescence (EL) of the device using n-ZnO/p-GaN heterojunctions shows the blue and greenish emissions, which are attributed to the emission from the p-GaN and deep-level defects. In this work, the n-ZnO:Ga/p-GaN:Mg heterojunction light emitting diodes (LEDs) were fabricated at different growth temperatures and carrier concentrations in the n-type region. The effects of the growth temperature and carrier concentration on the electrical and emission properties were investigated. The I-V and the EL results showed that the device performance of the heterostructure LEDs, such as turn-on voltage and true ultraviolet emission, developed through the insertion of a thin intrinsic layer between n-ZnO:Ga and p-GaN:Mg. This observation was attributed to a lowering of the energy barriers for the supply of electrons and holes into intrinsic ZnO, and recombination in the intrinsic ZnO with the absence of deep level emission.

• 유통과학연구
• /
• 제12권12호
• /
• pp.83-92
• /
• 2014

Purpose - A business ecosystem refers to mutually dependent systems interconnected by a loose foundation of various ecosystem members such as customers, suppliers, partners, and other stakeholders. The ecosystem-based strategy attempts to achieve competitive advantage for firms by enriching a business ecosystem or building a sustainable business ecosystem through the collaboration and co-evolution of its members. A sustainable business ecosystem is a source of competitiveness for firms anda manageable resource for gaining a competitive advantage. Customers represent the core membership of the business ecosystem and play a pivotal role in building a sustainable business ecosystem. This study examines the effects of customer participation on economic and social value in the business ecosystem and suggests a course of action for building a sustainable business ecosystem. Research design, data, and methodology - Two business cases of South Korea are selected from two different business types: business-to-business (B2B) and business-to-customer (B2C) firms. Business ecosystems for B2B and B2C firms reflect contrasting characteristics. Data was collected from in-depth interviews with four representatives of four firms. Results - The study suggested seven propositions for the relationships between customer participation and a sustainable business ecosystem through multiple case studies based on in-depth interviews. The results reveal the following four strategic actions for building sustainable business ecosystems based on the suggested propositions: alignment, systemization, socialization, and co-evolution. Alignment refers to achieving a harmonic balance or virtuous circle among the firm's mission, investment, and value creation. Systemization refers to building and implementing management and infrastructure systems rooted in the corporate culture. Socialization of customers in the business ecosystem reinforces the harmony or virtuous cycle. Finally, co-evolution is associated with the relationship between firms and customers as buyer firms in a restricted business ecosystem. Conclusions - This study considers multiple cases for the execution of a sustainable business ecosystem in collaboration with customers and suggests seven propositions and four strategic actions. The results are based on qualitative data from interviews with business associates from two firms in an open business ecosystem and two firms in a restricted business ecosystem, both in South Korea. Our research results regarding two contrasting business ecosystems shed light on business issues and policy making in Asian business environments, which are in the transition stages from a traditional conglomerate-driven to an inclusive growth-driven economy. The business ecosystem itself should be considered a manageable resource for firms' competitive positions in the market. A customer is a member of the business ecosystem and should thus be viewed not only as a purchasing entity and an object of relationship management but also as a co-creator of value. Therefore, firms should collaborate with customers to build sustainable business ecosystems. For this, firms must create social value, which cannot be created by customers alone, within the business ecosystem. Then, customers participate in a business ecosystem and build it to be favorable to them. Implications for academics and practitioners were suggested.

• 한국작물학회지
• /
• 제58권3호
• /
• pp.220-225
• /
• 2013

2001년 국립식량과학원 인공기상실에서 수경재배로 규산의 시용 여부가 영양생장기 벼의 수분과 질소흡수량에 미치는 효과를 조사하여 규산시용 여부 및 공급된 질소의 형태별 처리에 의한 시험품종들의 수분과 질소이용효율을 산출한 결과는 다음과 같다. 1. 처리 67일 후의 벼 건물중은 규산처리 시험구 및 $NH_4+NO_3$ 혼합시용 처리구가 규산을 처리하지 않은 시험구 및 NH4 단독시용 처리구보다 유의하게 증가하였음. 2. 이앙 후 67일간 조사된 벼의 수분흡수량은 규산처리와 규산 무처리 간의 차이가 없었으나 질소흡수량은 규산 무처리에 비해 규산처리구에서 유의하게 증가하였음. 3. 질소형태별로는 $NH_4$ 단독 시용보다$NH_4+NO_3$ 혼합시용에서 규산처리 여부와 관계없이 수분과 질소흡수량이 월등히 많았음. 4. 수분이용효율은 규산처리 시험구가 규산을 처리하지 않은 시험구에 비해 유의하게 증가하였으나 질소형태별 처리에서는 차이가 없었음. 5. 질소형태의 혼합처리가 암모늄태 단독처리보다 질소 흡수량은 유의하게 많았으나 질소이용효율은 감소하였음.

• 한국식품저장유통학회지
• /
• 제20권3호
• /
• pp.365-371
• /
• 2013

쌀을 원료로한 전통주의 우수성을 밝히고자 일반계통 3종, 통일계통 2종 및 태국산 인디카 품종 1종 등 총 6종에 대한 약주의 이화학적 특성과 DPPH radical 소거활성 및 SOD 유사활성 등 항산화활성을 측정하였다. 쌀 품종에 따른 약주의 시료구별 pH는 일미벼와 한아름벼로 담금한 약주의 pH가 4.14와 4.07로 다른 시료구에 비해 높았고, 그 외 시료구는 3.92~3.98이었다. 총산 함량은 태국산 쌀의 인디카 품종으로 담금한 약주의 총산 함량이 0.56%로 가장 높았다. 환원당 함량은 국내산 일반계통 품종과 통일계통 품종은 2.12~2.59%로 비슷하였으나, 태국산 인디카 품종은 3.59%로 다른 시료구에 비해 다소 높았다. Ethanol 함량은 통일계 품종인 한아름벼를 이용해 담금한 약주가 19.14%로 가장 높았고, 태국산 인디카 품종으로 담금한 약주는 13.97%로 가장 낮았다. 유기산 함량은 태국산 인디카 품종으로 담금한 약주가 3,491.8 mg%로 가장 높았으며, 주요 유기산은 lactic acid였다. 쌀 품종에 따른 fusel oil 총량을 보면 태국산 인디카 품종으로 담금한 약주가 1,270.35 mg/L로 가장 높은 함량을 보였고, Fusel oil 류 중 2-butyl alcohol이 가장 많은 함량을 보였다. 시료별 DPPH free radical 소거능은 태국산 인디카 품종으로 담금한 약주에서 소거능이 높았고, 일미벼 및 한아름벼로 담금한 약주는 상대적으로 약하였다. SOD 유사활성 또한 태국산 인디카 품종으로 담금한 약주가 60.10%로 가장 높았으며, total polyphenol 함량 역시 태국산 인디카 품종으로 담금한 약주가 국내산 품종으로 담금한 약주에 비해 약간 높았다. 쌀품종에 따른 약주의 항산화 활성을 비교한 결과 국내산 품종과 태국산 품종 모두에서 활성이 확인되었다.