At Pyropia farms, organic acid treatments have enhanced productivity and quality by removing pest algae (such as Ulva spp. and diatoms) and reducing the occurrence of diseases. Ulva spp. attaches to the Pyropia nets competing for inorganic nutrients & space and diminishing productivity. Additionally, the presence of attached contaminants (such as diatoms and middy particles) on the Pyropia nets negatively affects the quality of Pyropia. This study investigated the effects of removing Ulva linza and washing the Pyropia yezoensis nets using an activating treatment agent (organic acid and highly saline solution) with an air bubble device. The results of measuring the dead cell ratios after treatment under different conditions showed that the dead cell ratio of U. linza did not significantly increase when the air bubble device combined the activating treatment agent with the activating treatment agent alone. When washing the P. yezoensis nets, the air bubble device was about 19-37% more effective than the activating treatment agent alone. The findings of this study suggest that the air bubble device enhances the efficacy of the activating treatment agent, resulting in the effective cleaning of the Pyropia nets.
The purpose of this study is to identify the major peacekeeping activities that the Korean armed forces has performed from the past to the present. To do this, we collected 692 press releases from the National Defense Daily over the past 20 years and performed topic modeling and social network analysis. As a result of topic modeling analysis, 112 major keywords and 8 topics were derived, and as a result of examining the Korean armed forces's peacekeeping activities based on the topics, 6 major activities and 2 related matters were identified. The six major activities were 'Northeast Asian defense cooperation', 'multinational force activities', 'civil operations', 'defense diplomacy', 'ceasefire monitoring group', and 'pro-Korean activities', and 'general troop deployment' related to troop deployment in general. Next, social network analysis was performed to examine the relationship between keywords and major keywords related to topic decision, and the keywords ‘overseas’, ‘dispatch’, and ‘high level’ were derived as key words in the network. This study is meaningful in that it first examined the topic of the Korean armed forces's peacekeeping activities over the past 20 years by applying big data techniques based on the National Defense Daily, an unstructured document. In addition, it is expected that the derived topics can be used as a basis for exploring the direction of development of Korea's peacekeeping activities in the future.
한국 동해안 삼척시 갈남 해역의 조간대와 조하대에 생육하는 해조류의 군집구조 변화와 무절산호조류의 분포현황을 2010년 8월부터 2011년 5월까지 계절별로 총 4회 조사하였다. 연구기간에 녹조류 14종, 갈조류 33종, 홍조류 65종이 출현하여 총 112종 채집 및 동정되었다. 이 중 29종은 일 년 내내 출현하였다. 생물량을 근거로 한 우점종은 구멍갈파래(Ulva pertusa), 불레기말류(Colpomenia spp.), 모자반(Sargassum fulvellum), 톳(Sargassum fusiforme), 몽당잎모자반(Sargassum muticum), 지충이(Sargassum thunbergii), 작은구슬산호말(Corallina pilulifera)과 우뭇가사리(Gelidium elegans)였다. 해조류의 연평균 생물량은 건중량으로 66.7 gm-2이었고, 여름에 107.5 gm-2로 최대였고 가을에 36.2 gm-2로 최소값을 기록하였다. 기능형군 분석에서는 성긴분기형(coarsely branched form)이 전체 해조에서 40.0~48.6%를 차지하였다. 엽상형(sheet form), 사상형(filamentous form) 및 성긴분기형을 포함한 기회종인 생태학적 상태그룹 ESG II는 46∼61종으로서 76.7∼82.4%를 차지하였다. 각상형의 무절산호조류는 모든 계절에 출현하였으며, 대표적인 종이 혹쩍(Lithothamnion lemoineae), 혹돌잎(Lithophyllum okamurai), 납작돌잎(Lithophyllum yessoense), 나팔가시돌잎(Hydrolithon gardineri)이었다. 동해안 갈남 해역에서 무절산호조류의 피도는 선행 연구에서 36.8%였으나, 금번에 11%로서 감소하고 있음을 확인하였다.