RESEARCH ON CHANGES OF TOPOGRAPHICAL FEATURES AND VEGETATION ON A SAND BAR DUE TO FLOODS

SUGIO SATORU,WATANABE KUNITOSHI 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Colony structure and caste distribution in living trees of the Ryukyu drywood termite, Neotermes sugioi (Blattodea: Kalotermitidae) in Okinawa Island

Sugio Koji,Miyaguni Yasushi,Yoshimura Tsuyoshi 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

Termites are major pests of houses and buildings, and also living plants such as agricultural crops, trees in forests, urban areas and gardens. However, in Japan, the basic ecology of termites nesting in living trees is not fully understood. In this study, we observed 255 colonies (nests) of the drywood termite Neotermes sugioi, collected in the field on Okinawa Island, and reported the frequency composition of the reproductive castes, the size of wood with termite gallery, the population size of colonies, and the relative position of the reproductive and non-reproductive castes within nests. Most colonies were headed by a primary queen and a primary king. However, colonies headed only by primary queens, primary kings, or neotenic kings, each accounted for approximately 5% of the colonies. A colony size of 1,000– 4,000 individuals (2058.2 ± 1695.0 [mean ± SD]) was common and the average length of colony branches was less than 100 cm. Queens and kings were found in the same or nearby nest areas, and more predominantly in the central or root side of nest wood areas. The termites may experience colony fragmentation and reproductive loss as a consequence of typhoons. Incipient colonies (i.e., colonies at an early stage of development) were found on 11.3% of branches of Leucaena leucocephala that did not show any obvious signs of infestation. In future research, it will be necessary to update the list of trees damaged by this termite species, compare the damage by tree species, and evaluate the economic impact.

Toward Japan-ROK Security Cooperation Beyond Northeast Asia

( Sugio Takahashi ) 한국국방연구원 2007 The Korean Journal of Defense Analysis Vol.19 No.3

Security cooperation between Japan and the ROK has unfolded just within Northeast Asia, rather than extending beyond the region. However, this does not mean that Japan-ROK cooperation beyond Northeast Asia is meaningless or impossible. In fact, such cooperation can play significant roles. First, the differences in attitude toward regional security cooperation do not come from conflicts of interest, but from differences in priorities. Since both countries depend on overseas trade in the Asia- Pacific region and energy supplies from the Middle East, the stability of sea lanes is a shared concern and cooperation in this regard will serve both countries` national interests. Second, with the "normalization" of Japan`s security policy and modernization of the ROK navy and air force, both countries may have concerns about each other`s strategic intentions. Japan-ROK cooperation beyond Northeast Asia, based on strategic consensus on the importance of sea lanes, can reduce such suspicion on both sides. Third, faced with the rising China, the coordination of both countries` policies toward China to increase the "partner" aspect will serve the interests of long-term stability of the Asia-Pacific region. The Six-Party Talks play such a role now, but regional security cooperation beyond Northeast Asia will have broader effects on the Asia-Pacific region. This paper argues that there is a way forward for Japan-ROK security cooperation beyond Northeast Asia.

How Japan Can Manage the US Alliance at a Critical Juncture

Sugio Takahashi 동아시아재단 2017 Global Asia Vol.12 No.4

Changing Security Landscape of Northeast Asia in Transition

Takahashi Sugio(다카하시 스기오) 한국전략문제연구소 2012 전략연구 Vol.55 No.-

Strategic landscape in Northeast Asia is dramatically changing. In North Korea, after repeated provocations, Kim Jong Il was dead in 2011 and Kim Jong Un succeeded the position of the leader of North Korea. April 2012, while it was failed, North Korea launched long range missile. This event illustrates the fact that North Korea seriously continues to develop long-range ballistic missiles. With anotherconsistent effort to develop nuclear weapons, North Korea causes unpredictable instability in Northeast Asia. And rising China brings about even more unpredictability (although not necessarily instability) in this region. After two-decade rapid economic growth, China overtook Japan as a national GDP scale to be the second largest economy in the world. While Chinese economy is now indispensable for regional and world economic growth, China sometimes take assertive behaviors and such behaviors has raised concern among regional countries, especially countries at South China Sea and East China Sea. On the other hand, since economic interdependence with China has deepened and spread, shaping the future of “win-win” for both China and regional countries is the most important regional strategic challenge. In such radically changing region, both Japan and Republic of Korea (ROK)face common strategic challenge, with some difference in nuance. Both countries share democratic values, market economy, being allies of the U.S., threatened by North Korea, and facing complex problems from the rise of China. Given rapidly changing strategic landscape, Japan and ROKshould deepen security cooperation both in the context of the coordination of two bilateral alliances and bilateral relations between Japan and ROK, to broaden range of choices for both countries. (Not to antagonize or to contain China) To think about such challenge, this paper discusses three issues: Japan’s recent development of security strategy, its attitude toward China discussed in Japanese think tank community, and future of Japan-ROK bilateral and Japan-US-ROK trilateral cooperation.

Damage and ecological characteristics of termite Neotermes koshunensis on Taiwan cherry tree Cerasus campanulata in Okinawa Island

Koji Sugio,Yasushi Miyaguni,Tsuyoshi Yoshimura 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

Termites are typical house pests that can also be harmful pests for living trees, although this topic has not received much attention. To clarify the damage to trees caused by dry-wood termites (Neotermes koshunensis), and the ecological characteristics of such damage, we conducted a study on Taiwan cherry trees (Cerasus campanulata) grown in parks, historical sites, and streets in the central-southern area of Okinawa Island, a subtropical region. Damage by N. koshunensis was confirmed in 21 of the 36 sites surveyed (58.3%) and in 76 of the 1076 trees surveyed (7.1%). However, damage by Formosan subterranean termites (Coptotermes formosanus), a house pest, was only observed at six sites (16.7%), and 10 trees (0.9%), indicating that most damage was caused by N. koshunensis. Furthermore, the probability of the presence of damaged trees close to other damaged trees was significantly higher than the probability of the presence of damaged trees close to undamaged trees, implying that destructive colonies spread from damaged trees to other trees nearby. Therefore, care for trees in the initial stages of termite invasion seems to be the best method for preventing the spread N. koshunensis damage to other trees in the same area. To our knowledge, this study is the first to report that dry-wood termite N. koshunensis are harmful pests for Taiwan cherry trees in Okinawa Island. Our results could be used to establish dry-wood termite countermeasures for garden tree species.

Evaluation of Carbon Fiber distribution in Unidirectional CF/Al Composites by Two-Dimensional Spatial Distribution Method

Moonhee Lee,Sungwon Kim,Jongho Lee,SeungKuk Hwang,Sangpill Lee,Kenjiro Sugio,Gen Sasaki 한국산업융합학회 2018 한국산업융합학회 논문집 Vol.21 No.1

Low pressure casting process for unidirectional carbon fiber reinforced aluminum (UD-CF/Al) composites which is an infiltration route of molten Al into porous UD-CF preform has been a cost-effective way to obtain metal matrix composites (MMCs) but, easy to cause non-uniform fiber distribution as CF clustering. Such clustered CFs have been a problem to decrease the density and thermal conductivity (TC) of composites, due to the existence of pores in the clustered area. To obtain high thermal performance composites for heat-sink application, the relationship between fiber distribution and porosity has to be clearly investigated. In this study, the CF distribution was evaluated with quantification approach by using two-dimensional spatial distribution method as local number 2-dimension (LN2D) analysis. Note that the CFs distribution in composites sensitively changed by sizes of Cu bridging particles between the CFs added in the UD-CF preform fabrication stage, and influenced on only LN2Dvar values.

Evaluation of Carbon Fiber distribution in Unidirectional CF/Al Composites by Two-Dimensional Spatial Distribution Method

Lee, Moonhee,Kim, Sungwon,Lee, Jongho,Hwang, SeungKuk,Lee, Sangpill,Sugio, Kenjiro,Sasaki, Gen The Korean Society of Industry Convergence 2018 한국산업융합학회 논문집 Vol.21 No.1

Low pressure casting process for unidirectional carbon fiber reinforced aluminum (UD-CF/Al) composites which is an infiltration route of molten Al into porous UD-CF preform has been a cost-effective way to obtain metal matrix composites (MMCs) but, easy to cause non-uniform fiber distribution as CF clustering. Such clustered CFs have been a problem to decrease the density and thermal conductivity (TC) of composites, due to the existence of pores in the clustered area. To obtain high thermal performance composites for heat-sink application, the relationship between fiber distribution and porosity has to be clearly investigated. In this study, the CF distribution was evaluated with quantification approach by using two-dimensional spatial distribution method as local number 2-dimension (LN2D) analysis. Note that the CFs distribution in composites sensitively changed by sizes of Cu bridging particles between the CFs added in the UD-CF preform fabrication stage, and influenced on only $LN2D_{var}$ values.