• 제목/요약/키워드: power trade

검색결과 581건 처리시간 0.028초

Ga2O3와 4H-SiC Vertical DMOSFET 성능 비교 (Performance Comparison of Vertical DMOSFETs in Ga2O3 and 4H-SiC)

  • 정의석;김영재;구상모
    • 전기전자학회논문지
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    • 제22권1호
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    • pp.180-184
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    • 2018
  • 산화갈륨 ($Ga_2O_3$)과 탄화규소 (SiC)는 넓은 밴드 갭 ($Ga_2O_3-4.8{\sim}4.9eV$, SiC-3.3 eV)과 높은 임계전압을 갖는 물질로서 높은 항복 전압을 허용한다. 수직 DMOSFET 수평구조에 비해 높은 항복전압 특성을 갖기 때문에 고전압 전력소자에 많이 적용되는 구조이다. 본 연구에서는 2차원 소자 시뮬레이션 (2D-Simulation)을 사용하여 $Ga_2O_3$와 4H-SiC 수직 DMOSFET의 구조를 설계하였으며, 항복전압과 저항이 갖는 trade-off에 관한 파라미터를 분석하여 최적화 설계하였다. 그 결과, 제안된 4H-SiC와 $Ga_2O_3$ 수직 DMOSFET구조는 각각 ~1380 V 및 ~1420 V의 항복 전압을 가지며, 낮은 게이트 전압에서의 $Ga_2O_3-DMOSFET$이 보다 낮은 온-저항을 갖고 있지만, 게이트 전압이 높으면 4H-SiC-DMOSFET가 보다 낮은 온-저항을 갖을 수 있음을 확인하였다. 따라서 적절한 구조와 gate 전압 rating에 따라 소자 구조 및 gate dielectric등에 대한 심화 연구가 요구될 것으로 판단된다.

이어도 쟁점과 중국 해군전략의 변화 (Ieodo Issue and the evolution of People's Liberation Army Navy Strategy)

  • 강병철
    • Strategy21
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    • 통권31호
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    • pp.142-163
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    • 2013
  • Ieodo is a submerged rock within a Korea's Exclusive Economic Zone(EEZ) in the East China Sea with its most shallow part about 4.6m below the sea level which has no specific rights for the EEZ delimitation. The United Nations Convention on the Law of the Sea (UNCLOS) stipulates that any coastal state has the rights to claim an EEZ that stretches up to 200 nautical miles from its shore, except where there is an overlap with a neighboring country's claims. Korea claims that Ieodo is within its EEZ as it sits on the Korean side of the equidistant line and the reef is located on the Korea section of the continental shelf. China does not recognize Korea's application of the equidistance principle and insists that Ieodo lies on its continental shelf. According to UNCLOS, Ieodo is located in international waters, rather than one country's EEZ as the two countries have failed to reach a final agreement over the delimitation of the maritime border. This study seeks to understand the evolution of the People's Liberation Army Navy(PLAN) strategy as main obstacles for the EEZ delimitation between Korea and China. PLAN's Strategy evolves from "coastal defense" to "offshore defence", since the late 1980s from a "coastal defence" strategy to an "offshore defence" strategy which would extend the perimeter of defence to between 200 nm and 400 nm from the coast. China's economic power has increased It's dependence on open trade routes for energy supplies and for its own imports and exports. China want secure Sea Lane. PLAN's "offshore defence" strategy combines the concept of active defence with the deployment of its military forces beyond its borders. China's navy try to forward base its units and to achieve an ocean going capability. China's navy expects to have a 'Blue Water' capability by 2050. China insists that coastal states do have a right under UNCLOS to regulate the activities of foreign military forces in their EEZs. China protests several times against US military forces operating within It's EEZ. The U.S. position is that EEZs should be consistent with customary international law of the sea, as reflected in UNCLOS. U.S. has a national interest in the preservation of freedom of navigation as recognized in customary international law of the sea and reflected in UNCLOS. U.S. insists that coastal states under UNCLOS do not have the right to regulate foreign military activities in their EEZs. To be consistent with its demand that the U.S. cease performing military operations in china's EEZ, China would not be able to undertake any military operations in the waters of South Korea's EEZ. As such, to preserve its own security interests, China prefers a status quo policy and used strategic ambiguity on the Ieodo issue. PLAN's strategy of coastal defence has been transformed into offensive defence, Korea's EEZ can be a serious limitation to PLAN's operational plan of activities. Considering China'a view of EEZs, China do not want make EEZ delimitation agreement between Korea and China. China argues that the overlapping areas between EEZs should be handled through negotiations and neither side can take unilateral actions before an agreement is reached. China would prefer Ieodo sea zone as a international waters, rather than one country's EEZ.

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IBC형 태양전지를 위한 균일하게 증착된 비정질 실리콘 층의 광섬유 레이저를 이용한 붕소 도핑 방법 (Boron Doping Method Using Fiber Laser Annealing of Uniformly Deposited Amorphous Silicon Layer for IBC Solar Cells)

  • 김성철;윤기찬;경도현;이영석;권태영;정우원;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.456-456
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    • 2009
  • Boron doping on an n-type Si wafer is requisite process for IBC (Interdigitated Back Contact) solar cells. Fiber laser annealing is one of boron doping methods. For the boron doping, uniformly coated or deposited film is highly required. Plasma enhanced chemical vapor deposition (PECVD) method provides a uniform dopant film or layer which can facilitate doping. Because amorphous silicon layer absorption range for the wavelength of fiber laser does not match well for the direct annealing. In this study, to enhance thermal affection on the existing p-a-Si:H layer, a ${\mu}c$-Si:H intrinsic layer was deposited on the p-a-Si:H layer additionally by PECVD. To improve heat transfer rate to the amorphous silicon layer, and as heating both sides and protecting boron eliminating from the amorphous silicon layer. For p-a-Si:H layer with the ratio of $SiH_4$ : $B_2H_6$ : $H_2$ = 30 : 30 : 120, at $200^{\circ}C$, 50 W, 0.2 Torr for 30 minutes, and for ${\mu}c$-Si:H intrinsic layer, $SiH_4$ : $H_2$ = 10 : 300, at $200^{\circ}C$, 30 W, 0.5 Torr for 60 minutes, 2 cm $\times$ 2 cm size wafers were used. In consequence of comparing the results of lifetime measurement and sheet resistance relation, the laser condition set of 20 ~ 27 % of power, 150 ~ 160 kHz, 20 ~ 50 mm/s of marking speed, and $10\;{\sim}\;50 {\mu}m$ spacing with continuous wave mode of scanner lens showed the correlation between lifetime and sheet resistance as $100\;{\Omega}/sq$ and $11.8\;{\mu}s$ vs. $17\;{\Omega}/sq$ and $8.2\;{\mu}s$. Comparing to the singly deposited p-a-Si:H layer case, the additional ${\mu}c$-Si:H layer for doping resulted in no trade-offs, but showed slight improvement of both lifetime and sheet resistance, however sheet resistance might be confined by the additional intrinsic layer. This might come from the ineffective crystallization of amorphous silicon layer. For the additional layer case, lifetime and sheet resistance were measured as $84.8\;{\Omega}/sq$ and $11.09\;{\mu}s$ vs. $79.8\;{\Omega}/sq$ and $11.93\;{\mu}s$. The co-existence of $n^+$layeronthesamesurfaceandeliminating the laser damage should be taken into account for an IBC solar cell structure. Heavily doped uniform boron layer by fiber laser brings not only basic and essential conditions for the beginning step of IBC solar cell fabrication processes, but also the controllable doping concentration and depth that can be established according to the deposition conditions of layers.

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한국청년의 이문화 변화와 커뮤니케이션 관계와의 실증적 연구 (An Empirical Study on the Between Cross-Culture Exchange and Communication(Negotiation) of Korean Youth)

  • 이제홍
    • 통상정보연구
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    • 제19권3호
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    • pp.153-174
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    • 2017
  • 시대환경변화에 따라 각국의 젊은이들은 다양한 문화를 습득하기 때문에 공통적인 문화를 형성하며, 타국의 문화를 쉽게 수용할 수 있다. 이에 기존의 선행연구 즉, E. T. Hall(1959)의 고배경문화와 저배경문화 그리고 Hofstede(1991)의 5개 차원(권력거리, 불확실성회피, 개인 또는 집단주의, 남성성 또는 여성성, 장기적지향성)을 기본으로 하여 한국의 젊은 청년들은 이문화변화가 어떻게 형성되고 있는지 그리고 이들 이문화 형성에 따른 협상이 어떻게 진행될 것인지 예측모형을 도출하여 미래의 한국 통상협상 모형을 재정립하고자 하는데 연구의 목적을 두고 있다. 한국인 젊은이는 집단주의 문화권을 가지고 있는 것으로 나타났으며, 불확실성 회피 성향이 있다는 기존의 선행연구와 일치하는 것으로 분석되었다. 반면 한국인은 장지지향성이 있으며, 권력간격이 매우 높으며, 남성주의가 강할 것이라는 실증분석 결과 반대의 경향이 나타나고 있다. 대체적으로 한국 젊은이의 이문화 변화 유형은 남성주의보다는 여성주의 경향이 강하며, 가부장적이고 권위적인 측면보다는 가정적인 측면으로 변화함에 따라 권력간격이 낮은 유형으로 변모하고 있다. 또한 장기지향적인 성향이 아니며, 즉각적인 어떠한 사안에 즉각적인 반응과 해결하고 하는 유형으로 변화하고 있다.

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조건부가치측정법(CVM)을 이용한 바다목장과 바다숲의 비시장 경제가치 연구 (A Study on the Non-market Economic Value of Marine ranches and Marine Forests Using Contingent Valuation Method)

  • 김순미;소애림;신승식
    • 수산경영론집
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    • 제51권3호
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    • pp.1-15
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    • 2020
  • The Korean government has been carrying out the marine ranch development project since 1998 with the purpose of responding to the decrease in coastal fishery resources and fishery income, preparing a systematic management system for the sustainable use of fishery resources and realizing advanced fisheries power by expanding and upgrading fisheries resource development projects. In addition, the government established the Korea Fisheries Resources Agency and promoted projects for the protection and management of fishery resources by increasing basic productivity by artificially creating marine forests in areas where whitening events occur. Since the project of building marine ranches and marine forests requires immense government financial support, it is important to estimate the economic value and thoroughly evaluate the feasibility of the project. In this paper, the project of non-market economic value of the development of marine ranches and the development of marine forests was estimated. CVM (Contingent Valuation Method) was applied as a methodology for benefits estimation. Prior to the analysis, a one-on-one interview survey was conducted with participation of 512 residents and 514 residents respectively for the project of creating a marine ranch and developing a marine forest. A DBDC (Double-Bounded Dichotumous Choice) model was applied in the WTP (Willingness To Pay) analysis model and the socioeconomic variables of the surveyor, such as sex, age, education and income, were reflected in the model. The economic benefits from the two projects, namely, building of marine ranches and developing marine forests were estimated to be equal to 4,608 won and 7,772 won per household per year, respectively. According to the results of the survey, it seems that respondents think that marine forests are more valuable than marine ranches. This is as a result of ordinary citizens' thought that the marine ranches are more cost-effective than the marine forests. The benefits estimated through this study can be used for analysis of economic feasibility prior to carrying out the project of building marine ranches and developing marine forests, and are considered to be the valuable for policy-making purposes and finding social and economic consensus.

제주 해군기지의 역할과 전망 (Roles and strategic functions of the Jeju Naval Base)

  • 이춘근
    • Strategy21
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    • 통권39호
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    • pp.140-162
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    • 2016
  • The construction of Jeju Naval Base was finally completed and donated to the Republic of Korea Navy on February 26th this year. There is no doubt that the new base will contribute to the substantial augmentation of Korea's naval power and maritime security. However, we should note that the new naval base took a long and hard twenty-three years to be completed. In the 21st century, Korea should adopt a new strategy that can fulfill the security requirements of Korea for the new age of international relations. The 21st century is characterized by globalization, and in the world of globalization, a national boarder has become meaningless. In the late 20th century, after the Cold War, trade between countries have greatly increased and so did the importance of the seas. Having transformed from an agricultural country into a commercial country, Korea went from a continental state to a maritime state. Korea has become the 9th largest trading state, and obviously, the importance of the sea has become significant. Korea's national strategic focus needs to be on the sea for national survival. Thus, since the 1990s, the Korean Navy has planned to build the Jeju Naval Base. Jeju, due to its geopolitical characteristics, is extremely important to the 21st century Korea's economy and national security. Jeju is the starting point of the sea route that reaches out to the world, and at the same time, the ending point of the sea route that heads towards Korea. Jeju is located in the center of Northeast Asia and thus, Jeju Naval Base is extremely important for the area's security and order. Jeju Naval Base will be very useful not only for the maritime security of Korea, but also for keeping peace and order in Northeast Asia. Jeju Naval Base was the minimal effort against the six sea route security threats towards Korea. The six sea route threats are: 1) Threat from North Korea; 2) China's Threat towards Korea's sovereignty; 3) China's treat towards Korea's fishery; 4) Threat from Japan; 5) Threat towards Korea's sea routes; 6) Threat from recent phenomena of isolationism of the United States. Jeju Naval Base is built for both warships and civilian ships--such as cruise ships--to use. Just like the United States' Pearl Harbor, Jeju Naval Base will become not only the largest military base, but a beautiful tourist site.

Introduction of the representative mushroom cultivars and groundbreaking cultivation techniques in Korea

  • Jang, Kab-Yeul;Oh, Youn-Lee;Oh, Minji;Woo, Sung-I;Shin, Pyung-Gyun;Im, Ji-hoow;Kong, Won-Sik
    • 한국버섯학회지
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    • 제14권4호
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    • pp.136-141
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    • 2016
  • The production scale of mushrooms in Korea is approximately 600 billion won, which is 1.6% of Korea's gross agricultural output. In Korea, ca. 190,000 tons of mushrooms are harvested annually. Although the numbers of mushroom farms and cultivators are constantly decreasing, total mushroom yields are increasing owing to large-scale cultivation facilities and automation. The recent expansion of the well-being trend has caused an increase in mushroom consumption in Korea: the annual per capita mushroom was 3.9 kg ('13), whichis a little higher than that in Europe. Thus, mushroom export, mainly Flammulina velutipes and Pleurotus ostreatus, has increased since the mid-2000s. Recently, however, it is slightly reduced. Nevertheless, Vietnam, Hong Kong, the United States, and the Netherlands continue to export mushrooms, and Korea has increased its export to Australia, Canada, Southeast Asia, etc. Canned Agaricus bisporus, the first export of the Korean mushroom industry, reached it speak sales in 1977-1978. When Korea initiated trade with China in 1980, the international prices of mushrooms fell sharply, leading to shrinkage of the domestic markets. Spurred by the high demand to develop substitute goods for A. bisporus, the oyster mushroom (P. ostreatus) gained attention since it seemed to suit the taste of Korean consumers. Although the log cultivation technique for oyster mushroom was developed in the early 1970s, it required a great deal of labor. Thus, we developed the shelf cultivation technique, which is easier to manage and allows for mass production. In this technique, the growing shelf is made mafrom fermented rice straw, whichis the only P. ostreatus medium in the world and isused only in South Korea. After then, the use of cotton wastes as an additional material of medium, the productivity. Currently, we are developing a standard cultivation technique and environmental control system that can stably produce mushrooms throughout the year. The increase of oyster mushroom production may boostthe domestic market and contribute to industrial development. In addition, oyster mushroom production technology played a role in forming the basis for the development of bottle cultivation, which made mass production. In particular, bottle cultivation using liquid spawn could allow for the export of F. velutipes and Pleurotus eryngii. In addition, the white varieties of F. velutipes were second developed in the world after Japan. We also developed the new A. bisporus cultivar 'Saeah', which is easy to grow in Korea. In hopes to advance the mushroom industry, we will continue to develop cultivars with international competitive power and to improve cultivation techniques.

일러스트레이션과 광고 사회학의 관계 - 한국과 중국의 상품광고 포스터속의 근대 여성이미지를 중심으로- (A Comparative Study on Relationship between Advertising Sociology and Illustration - Focused on the Images of Modern Women in Commercial Posters in Korea and China-)

  • 장미경
    • 디자인학연구
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    • 제18권2호
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    • pp.27-36
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    • 2005
  • 상품을 팔기 위한 경제적 현상인 광고의 일러스트레이션은 일차적으로 상품내용을 전달하고자 소비자의 구매 욕구를 자극하기 위해 다양한 사회 문화적 코드를 사용하고 있다. 특히 현대사회에서 광고디자인은 대량생산을 통해 표준화된 상품을 차별화하기 위한 전략이드로 제품자체의 물리적 특징이나 사용가치 못지 않게 광범위한 상품외적 요소들인 사회학적 요인들이 개입하게 된다. 그 결과 상품판매 효과와는 상관없이 광고에 쓰인 문안이나 시각 이미지들이 독립된 사회적 영향력을 지니기도 하는데, 이러한 점에서 광고디자인은 시대상과 의식을 반영하고, 만들어 가는 공공의 문화적 현상이기도 하다. 그러므로 앞서 제시한 광고디자인의 특성과 역할을 전제로 본 논문은 근대기인 1900-1945년도의 한국과 중국의 광고포스터를 중심으로 당시 근대성의 성립과 전개를 개진한 시대상과 여성이미지의 관계를 고찰하고자 한다. 근대기의 한국과 중국이 서구화되면서, 광고 포스터에 등장한 여성이미지, 상품가치, 소비, 생활양식과 취향의 상관관계를 정치, 경제, 문화 현상 등을 광고일러스트레이션을 매개로 살펴보려고 한다.

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전통시장 상권 활성화에 대한 상인들의 의식구조 고찰 : S상권을 중심으로 (Consideration of Traditional Markets' Impact on the Self-Consciousness of Retailers: A Focus on the S Marketing Area)

  • 김민수;전진호;임진
    • 유통과학연구
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    • 제12권2호
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    • pp.17-25
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    • 2014
  • Purpose - This study used empirical methods to investigate the consciousness structure of vendors in the S marketing area, which is a commercial revitalization district in the country, and examined its effect on their business activities. Based on the results derived through the performance of an actual proof analysis, this study aims to facilitate the promotion of changes in the consciousness structures of traditional market vendors, with a view to allowing them to adapt to the current economic realities in the country. Further, this study aims to provide suggestions that would improve the efficiency of the commercial revitalization program of the government. Research design, data, and methodology - This study examined all the stores in the S marketing area using a questionnaire survey conducted over three weeks beginning on July 4, 2012, and involved the performance of a data analysis on 1,859 samples. The questionnaire consisted of two parts. The first part addressed the market revitalization and the second part addressed the store management strategies. Questionnaire responses were calibrated based on a Likert scale. Statistical analysis was conducted using PASW version 18.0. Results - The results of the analysis of the consciousness structure of merchants in the S marketing area have led to the discovery that they have a medium level of satisfaction with market revitalization. There was a difference in the perceptions of the concept of store management between merchants and customers. Merchants have poor strategies for store management, which do not go much beyond an imitation of the practices of large domestic discount stores. Conclusions - The appearance of big discount stores and the accompanying changes in people's consumption patterns have led to a decline in local market areas. The government has sought new ways to secure autogenic power for local markets. To create regional economies, the government enacted a revised "Law for creating traditional markets and shopping streets" in 2010 and introduced a commercial district revitalization program. This program, which originally supported only the S marketing area, has subsequently expanded into neighboring shopping districts so that the whole of the regional market can be revitalized. However, since the revitalization of the traditional market and the government support required for it were mostly limited to facilities, the result has not proved to be effective. Although there are several reasons why the government investment was characterized by poor efficiency, traditional market vendors' consciousness structure, which did not adapt well to the vagaries of time and its consequent changes, was a major cause. Only when vendors have a true merchant spirit can they have a real service focus that will enable them to clearly understand the distribution organization. This will have the effect of bring about complete customer satisfaction and will ensure the survival and development of traditional markets.

3세대 디바이스의 속성별 소비자 선호 분석 (Consumers' preference about the attributes of 3rd generation device)

  • 정재영;이주석;곽승준
    • 한국산학기술학회논문지
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    • 제18권3호
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    • pp.703-710
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    • 2017
  • 3세대 디바이스는 사물인터넷을 통해 지능화된 서비스와 어플리케이션을 활용할 수 있는 차세대 단말기이다. 스마트폰, 태블릿 PC와 같은 기존 스마트 디바이스 시장이 정체기에 접어들면서, 차세대 디바이스 시장을 이끌어 갈 3세대 디바이스 및 부품, 서비스 개발에 세계 각국이 주목하고 있다. 본 연구에서는 3세대 디바이스의 다양한 속성들에 대한 이용자 편익을 경제적 가치평가 방법론을 적용하여 측정해보고자 하였다. 이를 위해 대표적인 가치평가법의 하나인 컨조인트 분석법을 적용하였다. 컨조인트 분석을 위해 3세대 디바이스의 속성을 사용방식, 전력효율성, 라이프케어, 가격의 4가지로 선정했다. 혼합로짓모형을 적용하여 개별 속성들에 대한 한계지불의사액을 도출하였으며, 대부분 통계적으로 유의한 결과를 얻을 수 있었다. 응답자들은 사용방식 속성에서는 완전한 플렉서블 수준에 높은 선호를 보였으며, 전력효율성에 측면에서도 진보된 충전기술에 양(+)의 지불의사를 보였다. 또한 응답자들은 3세대 디바이스가 제공할 일상의 생산성 관리 서비스인 라이프케어 속성의 개선에 대해서도 지불의사가 있는 것으로 확인되었다. 본 연구에서 제시된 정량적 결과와 시사점은 3세대 디바이스 시장을 위한 정책 및 제품, 서비스 전략 수립에 유용하게 활용할 수 있을 것으로 판단된다.