Food goods traded between Korea and Japan during the middle period of the Cho Sun era included Insam (Jinseng), rice, beans, honey, perilla oil, starch, adlay, walnuts, pine nuts, jujubes, hazelnuts, and dired chestnuts as exports ; and pepper as imports. The number of Japanese envoies that visited regularly was one thousand five hundred people a year. The receptions that were held for them during the middle period equaled those of the first term of the Cho Sun era, but these receptions were only held in Pu-san. The expense of daily meals was broken down into 8 grades ranging from \129,300 to 2133. The daily meals included Jo-ban (breakfast), Jo-seok-ban (breakfast and dinner), and Ju-jeom-shim (lunch) for the Japanese who visited regularly. During the course of a year, the total amount spent on daily meals was put at a billion won. The banquet style meals included Ha-seon-da-rye (a welcome tea party), Ha-seon-yeon (a welcome banquet), No-cha-yeon (a banquet that was held on the street), and Ye-dan-da-rye (a drink banquet that was held when silk was offered as a gift). It also included Byeol-yeon (a banquet out of the dordinary), Sang-seon-yeon (a farewell banquet), and Myong-il-yeon (a banquet that was held on a national holiday). The banquet style meals were composed of Ceon-tack (to set a table for dinner), Sang-hwa (a flower that was put on the food), Kwan-hwa (to offer a flower when a banquet was held), Ju-9-jan (the ninth wine glass), Dae-seon (meat), music, and Jung-bae-rye (a banquet that was held again after a banquet). The Cho Sun government held banquets forty five times for the Japanese, the food expense for the banquets was put at two hundred and thirty million won.

Food goods traded between Korea and Japan during the first term of the Cho Sun era included Omija (fruit of the Maximowiczia chinensis), Jat (pine nuts), Insam (Jinseng), rice, and beans as exports ; and pepper, sugar, and medicinal stuffs as imports. The trade between Korea and Japan was a result of Japanese envoies' visiting. The official number of Japanese envoies who had exchanges with Koreans were two thousand people a year. Once the Japanese entered Korea, they did not need to pay for their living expenses for the length of their visit because the Cho Sun government bore the whole expense. The Cho Sun government gave formal receptions to them, which included daily meals as well as banquet style meals. The daily meals included Jo-ban (breakfast), Jo-seok-ban (breakfast and dinner), and Ju-jeom-sim (lunch). Meals were served four times a day. The banquet style meals included Sam-po-yeon (a banquet that was held in Sam-po), Kyong-joong-young-jeon-yeon (a farewell banquet, and a welcome banquet that was held in Seoul), Jyu-bong-bae (to offer a guest a drink by day), No-yeon (a banquet that was held on the street), Kwol-nae-yeon (a banquet that was held within the Royal Court). It also included Ye-jo-yeon (a banquet that was held in Ye-jo), and Myong-il-yeon (a banquet that was held on a national holiday). The banquet style meals were composed of Ceon-tack (to set a table for dinner), Sang-hwa (a flower that was put on the food), Kwan-hwa (to offer a flower when a banquet was held), Ju-5-jan (the fifth wine glass), Dae-seon (meat), and music.

국제간 정보통신전달 수단으로 인공위성과 해저케이블이 상호보안적으로 사용되어 왔다. 특히 최근에 와서는 해저 광케이블의 등장으로 국가간 정보통신전달 수단으로 케이블의 역할이 급격히 증대되고 있다. 해저케이블은 열악한 해양환경에 노출되어 있으므로 건설시나 운용중에 손상 받을 가능성이 아주 크며 그로 인한 파급효과가 엄청나다. 또한 해저케이블 사고시 복구에 많은 시간과 어려움이 뒤따르며 비용도 막대하다. 따라서 해저케이블의 안전성을 확보하는 것은 매우 중요하며 이에 대한 보호대책이 절실하다. 본 논문에서는 해저케이블의 건설 및 운용상에 발생할 수 있는 여러 불안전 요인들을 찾아 그에 대한 대책방안을 고찰해 보고자 한다.

이동통신용 고주파 표면탄성파(SAW) 필터를 36˚Y-X LiTaO3압전기판과 IIDT 전극구조를 이용하여 제작하였다. 제작한 SAW 필터의 중심주파수는 주파수 응답 특성 측정 결과 설계한 중심주파수보다 낮아짐이 관찰되었다. 이러한 단점을 보완하고 미세한 주파수의 조절을 가능하게 하기 위해 SiNx 유전박막을 보호막으로 증착하여 이에 따른 주파수 특성 변화를 관찰하였다. SAW파장에 대한 SiNx 유전 박막의 두께비를 증가시킬수록 SAW 진행 속도가 증가하여, 제조한 필터의 중심주파수를 높게 이동시킬 수 있었다. 그러나 유전박막의 두께가 증가할수록 필터의 삽입손실이 증가하는 문제점이 존재하였다.

In this study, prototype DAU with LoRa wireless communication module is designed and manufactured. Also, the customized software is developed for the automatic data transmission to end-user from ThingPlug server of SK telecom LoRa network. For verification of the developed wireless monitoring system, DAU was installed on bridge construction site. The reliability of data and operational stability was evaluated by comparison with data from conventional monitoring system.