Time-resolved laser fluorescence spectroscopy (TRLFS) and excitation-emission matrix (EEM) spectroscopy were used to study the interaction of U(VI) and natural organic matters (NOMs) in groundwater. Various types of groundwaters (DB-1, DB-3 from KURT site and OB-1, OB-3 from a U deposit in Ogcheon metamorphic belt) were used as samples. Pulsed Nd-YAG laser at 266 nm (Continuum Minilite) was used as the light source of TRLFS. The laser pulse energy of 1.0 mJ was fixed for all measurements. The luminescence spectrum was recorded using a gated intensified chargecoupled device (Andor, DH-720/18U03 iStar 720D) attached to the spectrograph (Andor, SR-303i). EEM spectra were measured using a spectrofluorometer (Horiba Scientific, Aqualog) equipped with a 150 W ozone-free xenon arc lamp. Excitation spectra were recorded by scanning the excitation wavelength from 200 to 500 nm. Emission spectra were measured using a CCD in the wavelength range of 242–823 nm. In the case of the recently collected DB-1 samples, it was observed that the U and NOM quantities decreased compared to the samples collected before 2016. For some DB-1 samples, the amount of dissolved organic carbon indicating the presence of NOM was significantly reduced, and changes consistent with this phenomenon were observed in the EEM spectrum. The time-resolved luminescence characteristics (peak wavelengths and lifetime) of U(VI) in the DB-1 samples agree well with those of Ca2UO2(CO3)3(aq). This U(VI) species remains stable, even in samples taken five years ago. The estimated amounts of U and NOM from the spectroscopic data of DB-3, OB-1, and OB-3 samples are relatively low compared to DB-1 samples. When a known amount of U(VI) was mixed in each groundwater, the time-resolved luminescence spectrum exhibited a characteristic spectral shape different from the expected luminescence intensity. This phenomenon is presumed to be due to the interaction between U(VI) and NOM in groundwater. The results of this study suggest that the chemical speciation of NOM as well as U(VI) is required to understand U behavior in groundwater.

KURT(KAERI Underground Research Tunnel) 지하수에 존재하는 천연 유기물질과 6가 우라늄(U(VI))화학종의 상호작용을 레이저 분광학 기술을 이용하여 조사하였다. 지하수 시료에 266 nm 파장의 레이저 빛을 입사시켜 자외선 및 파란색 파장 영 역에서 방출되는 천연 유기물질의 발광 스펙트럼을 관측하였다. 0.034-0.788 mg·L-1 농도 범위의 우라늄이 함유된 지하수에 서는 녹색 파장 영역에서 방출되는 U(VI) 화학종의 발광 스펙트럼을 측정하였다. 지하수에 함유된 U(VI) 화학종의 발광 특 성(피크 파장 및 발광 수명)이 실험실에서 제조한 표준용액에 함유된 Ca2UO2(CO3)3(aq)의 발광 특성과 매우 유사하다는 것 을 확인하였다. 지하수에 존재하는 U(VI) 화학종의 발광 세기는 표준용액에 함유된 같은 농도의 Ca2UO2(CO3)3(aq)의 발광 세기에 비해 약하다. 표준용액의 Ca2UO2(CO3)3(aq)를 천연 유기물질이 함유된 지하수에 섞었을 때에도 Ca2UO2(CO3)3(aq)의 발광 세기가 감소한다. 이러한 현상의 원인을 지하수의 천연 유기물질과 Ca-U(VI)-탄산염 화학종의 상호작용으로 인해 비 발광성 U(VI) 착물이 형성되기 때문인 것으로 설명하였다.

Global warming can seriously influence on the interaction between pest and natural enemy in the agroecosystem due to the differences in optimal temperature ranges. Two aphid-ladybug systems, Myzus persicae-Coccinella septempunctata (M-C) and Aphis gossypii-Coccinella septempunctata (A-C) in the pepper crop were simulated, respectively under four different temperature scenarios including crop development over 244 days with the assumption that the average temperature is higher by 1, 3, and 5 °C than that in Seoul in 2000. Temperature-dependent functions for each aphid-ladybug system were embedded in Rosenzweig-Macathur predator-prey model to explore their population dynamics, and then Dynamic Index was used to quantify the strengths of species interactions. The result shows that the predator-prey population cycles as well as species interactions are getting shorter and stronger in both systems as temperature increased. Especially, the excessively high temperature scenario in Aphis gossypii-Coccinella septempunctata system could result in the extreme species interaction. Therefore, the increasing temperature can facilitate the effectiveness of biological control because of growing crop plant development and much stronger species interaction, although there are increases of the frequency of pest occurrences.

In this paper, we present a serious game that can prevent elderly people from brain illness using natural finger interaction and Fumanet exercise. As population of elderly people has continually grown in our society, brain illness like dementia can be naturally observed, which makes treatment cost up rapidly. Hence, we propose Leap-Motion based serious game for elderly people, which uses natural finger motions to interact with game contents. In our approach, we enhance finger motion recognition rate by adding auxiliary conditions that is superior to ordinary Leap-Motion APIs. Finally, we have also carried out user study and quantitative analysis to verify our methods.

In this paper, we propose the escape game Loony considering natural interaction. For user's immersion, the proposed game is designed similar to the real world such as a security card key, its card reader, coin, and a vending machine. In order for the user to easily understand the situation in the virtual environment, the proposed game provides enough information in game user interface. For easy operation, the proposed game reacts based on simple input method: mouse and just few keys on keyboard. For the purpose of verifying the effects of the interaction between the proposed game and the user, we compare the proposed game with two previous escape games based on the observational evaluation and the questionnaire evaluation. The evaluation results show that the proposed game is better than the previous games on the operation feeling and the situational awareness of the users.

탐구는 과학교육의 본질을 설명해주는 결정적인 특징이다. 최근에는 스스로 문제를 제기하여 탐구하고 그것을 의사 소통하는 능력을 포함한 논증이 강조되고 있는데, 학교 탐구학습 맥락에서는 자율적이고 활발한 상호작용의 측면에서 그 한계가 지적되고 있다. 그래서 대안으로 비형식 맥락에서의 탐구학습이 제안되고 있으며, 이에 본 연구는 국립과천과학관 내 자연사관을 자유 관람하는 중학생 소집단의 대화적 탐구에서 나타나는 상호작용 유형을 밝히고자 하였다. 이를 위해 중학생 13그룹의 탐구적 대화 42사례를 대상으로 탐구요소 및 상호작용 유형을 분석하였다. 탐구요소는 문제제기, 자료수집, 설명의 세 가지로 구분하였고, 상호작용은 대화의 흐름을 화살표로 도식화하여 나타내었다. 문제제기로부터 탐구가 시작된다고 보았으며, 문제제기 이후 후속적인 반응에 따라 유형이 구분되었는데, 총 7가지 유형이 발견되었다. 그 유형은 문제제기 공유, 문제제기-단순응답, 문제제기-단순설명, 문제제기-단순설명-(자료수집)-자료기반 설명, 문제제기-자료수집-자료기반 설명의 5가지로 크게 나누어지고, 가장 많은 빈도를 보인 유형 2는 다시 소극 회피적 응답, 부정확한 응답, 패턴의 반복으로 세분화되었다. 본 연구는 비형식 탐구학습에서 학교 탐구학습과 차별화되는 상호작용 패턴을 파악하였다는 점에서 기존 연구들과 차별성을 가지며, 비형식 탐구학습에서 상호작용 유형을 기술하고 있다는 점에서 비형식 탐구학습 연구를 위한 기초를 제공하였다는 의의를 가진다.

This paper investigated interaction patterns of L2 learners and their native speaker counterparts in EFL classrooms and proximal social settings. To this end, data were collected from an English cafe at a university (i.e., pseudo-natural setting) and from an English conversation class at a university (i.e., classroom setting). Data analysis focused on teachers" question types, feedback patterns, and learners" responses towards feedback. The analysis based on utterance frequency revealed that students displayed higher participation rate in the pseudo-natural settings. With regards to teacher questions, teachers used more referential questions than display questions in both settings. However, there were twice as many teachers" feedback in the pseudo-natural setting compared to the classroom setting, but the frequent feedback did not slow down the conversation and did not always lead to self-repair. In addition, students in two settings differed in terms of their preferences to feedback in different linguistic categories.