생활치 표백술 후 수종의 자유 산소기 제거제 처리가 복합 레진-법랑질 전단 접착 강도 및 파절 양상에 미치는 영향

임경한,금기연,김애리,장수미 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5

Tooth bleaching has been prevailing recently for its ability to recover the color and shape of natural teeth without reduction of tooth material. However, it has been reported that bleaching procedure adversely affects the adhesive bond strength of composite resin to tooth. At the same time the bond strength was reported to be regained by application of some chemical agents. The purpose of this in vitro study was to investigate the effect of the removal of residual peroxide on the composite- enamel adhesion and also evaluated fracture mode between resin and enamel after bleaching. Sixty extracted human anterior and premolar teeth were divided into 5 groups and bleached by combined technique using office bleaching with 35 % hydrogen peroxide and matrix bleaching with 10% carbamide peroxide for 4 weeks. After bleaching, the labial surfaces of each tooth were treated with catalase, 70% ethyl alcohol, distilled water and filled with composite resin. Shear bond strength was tested and the fractured surfaces were also examined with SEM. Analysis revealed significantly higher bond strength values. (p<0.05) for catalase-treated specimens, but water-treated specimens showed reduction of bond strength, alcohol- treated specimens had medium value between the two groups(p<0.05). The fracture mode was shown that the catalase group and the alchohol group had cohesive failure but the water sprayed group had adhesive failure. It was concluded that the per-oxide residues in tooth after bleaching seems to be removed by gradual diffusion and the free radical oxygen from peroxide prevents polymerization by combining catalyst in the resin monomer. Therefore it may be possible to eliminate the adverse effect on the adhesion of composite resin to enamel after bleaching by using water displacement solution or dentin bonding agent including it for effective removal of residual per-oxide Key words : Vital tooth bleaching, Shear bond strength, Composite resin, Fracture mode catalase, Ethylalcohol, Free oxygen radical, Adhesive failure, Cohesive failure

Impacts of Russia-Ukraine War on East Asian Regional Order

임경한,김재호 통일연구원 2022 International journal of korean unification studie Vol.31 No.2

The outbreak of ‘the war in Ukraine’ in 2022 has had impacts well beyond Europe, spreading throughout international society. This study reviewed the structural impact of the war on the global order, as well as on the regional order in East Asia. As a result, the study came to the following conclusions: First, rigidity in the international system is increasing, and regional blocs are gaining strength. Second, the U.S., having previously maintained regional security in Europe and Asia separately, is now seeking strategic change as Russia and China working closely together. Third, the U.S. is courting cooperation with its allies and partners by cementing stronger than-ever economic and military ties in East Asia. Simultaneously, South Korea faces both structural changes in the international order and North Korea’s nuclear threats. Against this backdrop, South Korea needs to pursue a principled and integrated security strategy, along with a flexible strategy compartmentalized into sectors to promote its security. Above all, South Korea needs internal balancing—including the strengthening of its security capabilities —while pursuing the development of innovative organizations. In external balancing, South Korea needs to make bold decisions and greater efforts by pursuing a global comprehensive strategic alliance with the U.S.

중국의 일대일로 전략과 미국의 인도-태평양 전략 경쟁 하 주변국의 대응전략

임경한 동아시아국제정치학회 2019 국제정치연구 Vol.22 No.4

이 연구는 미·중의 전략 경쟁 속에서 태국, 필리핀, 일본 등 역내 미국의 동맹국들은 과연 어떤 시각으로 미·중의 경쟁을 바라보고 있는지를 다루고 있다. 중국은 일대일로 전략을 추구하면서 주변 국가들에게 경제력을 통한 영향력을 강화함으로써 미국의 군사적인 동맹을 약화시키는 것을 목표로 설정하고 있다. 반면 미국은 미·중 전략 경쟁의 무대가 되는 아시아·태평양 주변국들 중 미국과 군사협력을 이어나가고 있는 동맹 및 안보우호국들에 대한 지속적인 관계 강화를 통해 중국의 팽창적인 움직임을 견제하고자 한다. 이처럼 미·중은 직접적인 갈등에 더해 주변국들의 우호적인 지지를 획득하는 데 있어서도 경쟁적인 모습을 보이고 있는 것이다. 미·중의 전략 경쟁 속에서 태국과 필리핀은 경제적으로 중국과의 관계에서 국가이익을 극대화하면서, 미국과는 동맹국으로서의 관계를 고려한 군사협력을 잘 이어가고 있다. 어느 한 쪽을 자극하지 않으면서 중국으로부터 투자를 이끌어내 국가의 인프라를 구축하는 등 경제발전을 도모한다. 미국과의 연대를 통해 해양 영유권 확보 등 안보를 위한 군사협력 관계를 지속하려는 약소국의 유일한 선택지일 수밖에 없는 현실이다. 한편 일본은 강력한 경제력과 군사력을 이미 갖춘 상황에서 미국과의 전통적인 동맹 관계를 명확하게 최우선시하면서 중국과의 마찰을 줄이는 방향으로 경제·외교·군사 문제를 다루고 있다. This paper tries to explain the strategies of Thailand, Philippines, and Japan towards the rivalry of China's One Belt One Road Strategy and the US' Indo-Pacific Strategy. China seeks to promote the One Belt One Road Strategy while increasing economic influence on neighbouring countries, which eventually is to weaken the Us' military alliance. On the other hand, the US aims to keep up reinforcing military ties with its allies in the Asia-Pacific region, the domain where the US-China competition mainly takes place, to check the expansionism of China. Likewise, the competition between the two powers continues even in gaining friendly supports from the neighboring nations. In the midst of the US-China strategy competition, Thailand, the Philippines and Japan look forward to maximizing their national interests in the economic sector with China and in the military sector with the US through the alliance. The first two countries tend to avoid offending either side while still wishing to attract investment from China for the construction of infrastructure to promote the economic development, and to maintain the military cooperation with the US in the security sector such as securing maritime sovereignty, which is the sole realistic option that weak states may choose. Meanwhile, Japan deals with its foreign affairs in diplomatic and economic fields with its own strong power and clarifies that it prioritize the traditional alliance with the US, while at the same time minimizing unnecessary friction with China.

U.S. Indo-Pacific Strategy and New Southern Policy of South Korea - Based on Mutual Cooperation on the Maritime Security -

임경한,조현덕 한국해양수산개발원 2021 해양정책연구 Vol.36 No.2

The leaders of the Republic of Korea and the United States all recognize the importance of ASEAN and share the mutual assistance of policies targeting ASEAN. Above all, both countries not only acknowledge the importance of maritime cooperation but also agree to promote stable and peaceful Indian and Pacific Oceans. The Republic of Korea is implementing a New Southern Policy for long-term cooperation with ASEAN and India, which signifies an alignment with the U.S. Indo-Pacific Strategy on the stage of the Asia-Pacific waters. The New Southern Policy aims to present human-to-human exchange, win-win prosperity, and peace, the Republic of Korea could possibly boost ROK-U.S. alliance further by finding some areas that can be successfully linked to the U.S. Indo-Pacific Strategy. In the status quo of the twenty-first century, competition for maritime hegemony between or among the powers has been intensifing, which will now have an impact on creating an atmosphere of anxiety. Thus, in the perspective of the Republic of Korea, enhancing a ROK-U.S. bilateral cooperation for maritime security in the sphere of ASEAN will be a cornerstone for promoting the future-oriented ROK-U.S. alliance.

일대일로와 인도-태평양 전략에 대한 인도와 호주의 대응

임경한 연세대학교 동서문제연구원 2018 동서연구 Vol.30 No.4

This article studies the strategies of India and Australia towards the rivalry of China's One Belt One Road Initiative and the US Indo-Pacific Strategy. Many experts anticipate that India and Australia would benefit the most from the US-China economy and security rivalry. The two nations thoroughly investigate the strategy of the US and China, looking forward to maximizing their national interests while preparing themselves for the upcoming new international order. Both countries pursue to make economic benefits from China and to strengthen military security cooperation with the US. The two countries stay between the two great powers, but actively pursue their national interests. Their active hedging strategy as a middle power gives Korea implications of great importance in terms of how to set the foreign policy toward the US and China. 이 글을 통해 중국의 일대일로 전략과 미국의 인도-태평양 전략의 경쟁 사이에 놓인 인도와 호주의 대응전략을 살펴보았다. 두 강대국인 중국과 미국이 경제 및 안보 분야에서 상호 치열하게 경쟁하는 가운데 가장 많은 혜택을 누리면서도 전략적 딜레마에 고민할 것으로 예상되는 국가로 인도와 호주가 자주 언급된다. 인도와 호주는 미국과 중국의 전략을 면밀하게 살피는 가운데 국가이익을 극대화하고, 미래의 새로운 국제질서를 맞이할 준비에 분주하다. 공통적으로 인도와 호주 양국은 중국과의 관계 속에서는 경제적인 이득을 우선적으로 추구하고, 미국과는 군사안보 협력을 강화하는 모습을 보이고 있다. 인도와 호주는 미국과 중국 사이의 치열한 경쟁 상황 속에서 아슬아슬한 줄타기를 하면서도 적극적으로 국가이익을 추구하고 있다. 중견 국가로서 인도와 호주가 보여주는 적극적인 헤징 전략은 중국과 미국에 대한 우리나라의 대외정책 수립에 있어 중요한 시사점을 제공한다.

미얀마의 개혁 ‧ 개방과 미국의 對 미얀마 전략: 미얀마의 군부 주도 개혁 ‧ 개방을 중심으로

임경한,문종화 서울대학교 국제학연구소 2016 국제지역연구 Vol.25 No.2

In March, 2016, Myanmar under civilian President has been expediting reforms and open market policy with leadership of Aung San Suu Kyi and this change has been attracting the world’s attention. Myanmar’s extensive reform movement has yielded successful model of democratization which will bring Myanmar back into international politics. The United States placed economic sanctions on Myanmar since 1988, however, due to recent reformation by the civilian government, sanctions are being removed. The year of 2016 announced the new start of Myanmar, and the US government is interested in achieving its strategic object: expanding regional influence in Asia by showing deep interest in economic development of Myanmar. The US government’s aim is to not only securing regional presence of the US in the region but also support Myanmar to check on China’s ambition to become regional power. The Obama administration’s “Rebalancing” policy requires holistic approaches in military, diplomatic, and economic effort. Also, the US government should support Myanmar more closely on human rights issue and democratization, so that it can ensure the success of “Myanmar Spring”, which can spread around the region. 2016년 3월 민간 출신의 대통령을 내세운 미얀마는 아웅산 수치 여사의 주도하에 개혁‧ 개방의 속도를 높이고 있으며, 이는 국제사회의 이목을 집중시키고 있다. 이른바 미얀마의 봄이 시작된 것이 다. 미얀마의 움직임은 2011년부터 광범위하게 실시한 개혁‧ 개방과 민주화의 성공적인 모델로서 미얀마를 국제사회에 등장시킬 것으로 보인다. 미얀마의 개혁‧ 개방 노력을 추적해보면 1988년부 터시작된것을알수있다. 미국은지난1988년이후지속해온미얀마에대한제재를걷어올리는 작업을 이미 진행해오고 있었으며, 최근 들어 더욱 적극적으로 움직이고 있다. 2016년 미얀마의 새 로운 시대가 시작되었고, 미국은 미얀마의 지속적인 경제적 발전과 번영에 대한 관심을 증폭시킴으 로써 아시아에서의 영향력 확보를 위한 전략적 목표를 달성하고자 하는 것이다. 미국이 대 미얀마 전략에서 가장 중요시 하는 목표는 중국을 견제하는 가운데 아시아에서의 영향력을 지속적으로 확보 하는 것이다. 이를 위해 미국이 추진하고 있는 재균형(Rebalancing) 정책은 군사적인 노력뿐만 아니라 외교적, 경제적 노력 등 전 방위적인 접근을 필요로 한다. 또한 미국은 미얀마의 개혁‧개방 을 보장함으로써 궁극적으로는 미얀마의 인권문제 해결 및 민주화를 지원하여 아시아 주변국으로 파 급시키는 효과도 가져올 것으로 보인다.

핵태세검토보고서(NPR)를 통해 본 미국의 핵전략 특징

임경한 동아시아국제정치학회 2022 국제정치연구 Vol.25 No.4

이 연구에서 다루는 주제는 미국이 냉전 시기부터 현재까지 추진해오고 있는 핵전략에 관한 내용이다. 미국의 핵전략 관련 움직임은 미국이 일반자료로 공개하는 핵태세검토보고서(NPR: Nuclear Posture Review)를 통해 일정 부문 확인할 수 있다. 최초의 NPR은 1994년에발표되었고, 이후 미국은 비정기적이지만 행정부 변화에 맞춰 총 4번의 NPR을 추가로 발표했다. 미국이 시기별로 발달시킨 핵전략을 바탕으로 적국 대비 압도적으로 우세한 핵전력을확보하여 적의 핵 공격을 억제하려는 시도는 상당 부분 성공적으로 진행된 것으로 평가할 수있다. 미국이 추진해 온 핵전략과 핵전력 변화는 억제전략과 상쇄전략을 동시에 고려하여 크게 2가지 측면에서 요약할 수 있다. 먼저, 적국에 대한 압도적인 핵전력을 확보함으로써 미국주도의 핵 우위를 지속적으로 유지하는 것이 미국이 목표로 하는 핵전략의 핵심이다. 다음으로는 미국의 핵전력 우위에 도전하려는 국가들과의 핵전력 경쟁의 심화 양상을 제한하고 회피하기 위해 도전국과 핵무기 감축 및 제한에 관한 협약을 적극적으로 체결하는 것이다.

Same Bed, Different Dreams: US-Chinese Power Competition Over the East Asian Seas

임경한 경희대학교(국제캠퍼스) 국제지역연구원 2014 아태연구 Vol.21 No.1

This paper answers the causes of the security competition between the US and China in the East Asian Seas as the ultimate objective of the two great powers to achieve naval mastery in the region. This paper argues that economically and militarily, the incumbent global power, the US, and the challenging power regarding to economic and military power, China, are more likely to compete for their own national interests and security and so forth. It is notable that the level of US-Chinese security competition over the East Asian Seas has been changing. Security dilemma is changing into power competition and the competition is expected to intensify more and more. Thus, the East Asian Seas will be a contested zone for a while between the US and China with naval forces playing significant roles. All in all, the US has been attempting to contain China while China has been attempting to expand its maritime activities to avoid such containment. This is a typical one bed, different dreams phenomenon.

Global Access vs. Access Denial: US-Chinese Naval Security Competition in the East Asian Seas

임경한 국방대학교 국가안전보장문제연구소 2012 The Korean Journal of Security Affairs Vol.17 No.1

This paper tries to demonstrate how important national interests are to security competition between great powers during peacetime. Recent US naval strategy and force structuring can be interpreted as an affirmative naval stance against China in the East Asian seas. On the other hand, PLAN has been developing new platforms and capabilities that will extend its operational reach to address other concerns within the East and South China Sea, the Yellow sea, and possibly to the Indian Ocean and beyond the second island chain in the western Pacific. Remaining problems such as tensions between the US and China in the Yellow Sea, the Taiwan issue, and the Spratly Islands accelerate the possibility of naval conflict between the US and China in the East Asian seas. Moreover, their competition for security will bring negative consequences to the security environment of the East Asian seas. The US and Chinese naval security competition will worsen the maritime security environment in East Asia and maritime conflicts in East Asia are directly connected to Korea’s maritime security. Having these situations in mind, this paper offers several policy recommendations for preparing an optimum naval strategy and enhancing Republic of Korea (ROK) naval forces in the future.

Containing China: Rising China and U. S. Grand Strategy in East Asia

임경한 경희대학교(국제캠퍼스) 국제지역연구원 2012 아태연구 Vol.19 No.1

Recently, the US grasps the importance of the naval threat China is causing to the US and its allies in the East Asian Seas in the foreseeable future. Therefore, this paper focuses on strategy and operation of deployed US military forces, mostly about the US naval forces. Under these circumstances, the ultimate objective of this paper is to examine the US' containment strategy against China and its security commitment toward its allies and security partners in East Asia region. The US has still maintained its large naval forces in East Asia while the US Navy has been sharply reduced in Europe. The US should conduct a policy that is more preventive than offshore balancing for the prevention of enemy's competition. Moreover, the policy should be more proactive and threatening than selective engagement. Under this circumstance, the US has been using containment strategy by mostly using naval forces against China's naval expansion in the East Asian Seas. The main goal of US containment strategy against China is to prevent Chinese naval expansion. As a maritime based great power, the US, could effectively display naval forces to support its grand strategy. At the same time, the US has sought naval mastery in the East Asian Seas to increase their relative power against potential challengers such as China. It is also reasonable for the US to support its allies and security partners under the name of security commitment in the East Asian Seas. The US has finally decided to contain China in the region. In particular, the US has been containing against potentially threatening China by using naval forces.