한국연안에서의 해양생물 생태 조사방법 표준화

이재학 한국환경생물학회 2004 환경생물 : 환경생물학회지 Vol.22 No.1

Ecological methods were reviewed through reports such as environmental impact assessment and damage effect of fishery in the Korean watershed. Survey items in marine ecological field were included: phytoplankton, zooplankton, benthic animal, algae, adult fish, egg and juvenile of fish. A standardization of survey method in the field of community ecology was suggested to consider the convenience, frequency in use of device, accuracy of data collected from that. It is necessary that spatial data should be sufficiently acquired for statistical analysis of biodiversity and spatial comparison. Quantitative sampling method must be inevitably adopted based nature of biota and geographical type of the survey area. The same sampling method can make the data compared spatially but can't be applicable in all area. Standardizing survey method should be by no means under certain restriction of study and would become different according to survey environments. The first thing is minutely understanding about ecological character of biota inhabiting in certain area, and then determining survey method.

물리 문제 해결에 관한 최근 연구의 분석

박학규,권재술 한국교원대학교 과학교육연구소 1992 청람과학교육연구논총 Vol.2 No.1

In this paper, current research papers on Physics Problem Solving were analyzed according to the types of research purpose, method, subject and content of Physics, by using 3 Proceedings and 4 kinds of Journal, that is, the International Workshop(1983, Paris, France) and Conference (1983, Utrecht, The Netherlands) and Seminar(1987, Cornell University, U. S. A.) on Physics Education, and Journal of Research in Science Teaching (1984-1990) and Science Education (1986-1990). and Inter national Journal of Science Education(1987-1988) and Cognitive Science(1989-1990). There were 98 research papers on Problem Solving and among them 37 papers on Physics Problem Solving were selected for analyzing. The results of analysis are as follows; 1) The studies on Model of Novice Student were 22(59%), And those on Model of Desired Preformance, on Model of learning and on Model of Teaching were all much the same. 2) The theoretical studies were 10(27%), and the experimental ones 27(73%). Among the experimental studies, there were 16(59%) by using the written test, and 7(26%) by using the thinking aloud method. 3) The studies about university students as subjects were 20(54%). Probably, it seems the reason that most of reseachers on Physics Problem Solving were professors of university or graduate students. 4) Among the various fields of Physics, the studies on Mechanics were 24(63%) and those on Electromagnetics 6(16%). or graduate students.

물리 문제 해결 과정에서의 학생들의 사고 과정에 관한 연구

박학규,권재술 한국교원대학교 과학교육연구소 1994 청람과학교육연구논총 Vol.4 No.1

The purpose of this study was to analyze students' physics problem solving processes and to find the patterns of their problem spaces when high school and university students solved the physics problems. A total of 51 students in a high school and in two universities participated in this study. Their thinking processes in solving 5 physics problems on electric circuit were recorded by using 'thinking aloud' method and were transfered into protocols. The protocols were analyzed by the coding system of problem solving process. One of the major theoretical contributions of the computer simulation approach to problem solving is the idea of problem space. Such a concept of problem space was applied to physics problems on electric circuit in this study, and students' protocols were analyzed by the basic problem spaces which were made up from the item analysis by the researcher. The results are as follows: 1) On the average 4.0 test items among 5 ones were solved successfully by all subjects, and all of the items were solved correctly by only 19 persons among all of them. 2) In regard to the general steps of problem solving process, there was little difference for each item between the good solvers and the poor ones. But according to the degree of difficulty of task there was a good deal of difference. For a complex problem all of 4 steps were used by most of students, but for a simple one only 3 steps except evaluating step were used by most of them. 3) It was found in this study that most of students used mainly the microscopic approach, that is, a method of applying Ohm's law on electric circuit simply and immediately, not using the properties of electric circuits. And also it was observed that most of students used the solving from below, that is, a solving path in which they were the first to calculate physical quantities of circuit elements, before they caught hold of the meaning of the given problem regardless of the degree of difficulty.

시화호 오염수 방류에 따른 중형저서동물의 군집변동

김동성,이재학 한국환경생물학회 2000 환경생물 : 환경생물학회지 Vol.18 No.2

조하대 각 정점에서 중형저서동물의 그룹별 조성을 보면 총 22개의 그룹이 출현하였다. 배수 갑문 바로 앞의 정점에서는 방류 하루 후, 방류 일주일 후가 방류 하루 전에 비해 중형저서동물군집의 각 개체군의 개체수가 다른 정점에 비해 현저하게 감소함을 나타냈다. 우점하고 있는 분류군은 방류 하루 전에는 저서성 요각류가 가장 우점하고 있었고, 방류 하루 후에는 거의 출현하지 않는 현상을 보였다. 배수 갑문으로부터 약간 떨어진 정점에서는 앞의 정점과 같이 급격한 감소를 보이지는 않았지만 개체수가 서서히 감소하고 있음을 나타냈다. 이 정점에서는 모든 시기에 있어 항상 선충류가 가장 우점하고 있었고, 그 다음으로 저서성 요각류와 유공충류가 서로 번갈아 가며 우점하고 있음을 보였다. 배수 갑문으로부터 가장 멀리 떨어진 정점에서는 방류 후에도 전체적으로 그 개체수 값은 떨어지지 않음을 보여준다. 수직분포를 보면 배수갑문 앞 정점에서는 전 시기에 있어서 저서성 요각류는 표층 0∼1㎝에 가장 많이 분포하고 있었다. 저서성 요각류는 퇴적물의 심도가 깊어질수록 급격한 감소를 보이고 전반적으로 퇴적물 내 2㎝ 이하의 층에서는 거의 출현을 하지 않았다. 총 개체수를 보면 방류 전에는 표층 0∼1㎝에서 가장 높은 서식밀도를 보이고 심도가 증가함에 따라 개체수가 감소함을 나타내었으나, 방류 후에는 균일하지 않은 양상을 보여준다. 또한 방류 전에는 표층에 저서성 요각류가 400개체/10㎠ 이상 우점하고 있었지만 방류 후에는 거의 출현하고 있지 않음을 나타내었다. N/C비는 정점 4에서 방류 하루 전 0.7의 아주 낮은 값에서 방류 하루 후 약 30배에 달하는 19.0의 높은 값을 나타냈다. 이에 비하여 정점 6과 7에 있어서는 방류 하루 후에는 오히려 약간의 감소를 보이다가 방류 일주일 후 아주 높은 값을 보였다. 조만대 방아머리 갯벌의 경우는 정점 1에서만 일반적인 값을 보이고, 정점 2에서 아주 높은 값인 191.3을 나타냈다. 결론적으로 시화호 방류수는 중형저서동물군집에 직접적이며 상대적으로 아주 짧은 시간에 영향을 미치는 것으로 나타났으며, 이러한 특징은 중형저서동물이 장·단기적인 오염의 영향을 파악하기에 아주 유효한 대상 생물임을 시사한다. To alleviate the harmful effects from contamination, the Sihwa Lake waters have been regularly fluxed out into the ocean to mix and circulate with the oceanic waters, and then allowed to flow back into the lake. In the present study, eco-environmental impacts by the outflowing contaminated lake waters to the benthic communities of the coastal zones along Kyonggi Bay were examined at three separate areas. A total of 22 groups of meiobenthic animals were commonly found in the subtidal zones of the Bay. All groups of the meiobenthic animals on the 1^st and 7^th days after the outflow were remarkably reduced in numbers from the selected areas examined, as compared to those observed one day before the outflow. It was also found that the community structure of meiobenthos was changed drastically: At the station near the water gate, for example, where the immediate outflow of the lake water was encountered, the benthic harpacticoids, the group observed to be one of the predominant groups before the outflow, were found to have disappeared completely. For an area that was relatively far away from the water gate, the reduction rate of meiobenthos after the outflow events was slower and more gradual than the nearer sites. An area that is the farthest from the water gate, no reduction in any of the meiobenthos group was observed. The ratio between nematodes/copepods(N/C) was remarkably changed by the outflows at the station near the water gate: ONe day before the outflow, the ratio was 0.7 while the ratio was 19.0 at the station near the water gate. In contrast, at the stations relatively far from the water gate, the ratio decreased one day after the outflow event, but increasing trends were observed one week later. In the tidal flats, Station 1 exhibited the common observed regional values of the ratio whereas Station 2 showed a very high ratio of 191.3. The results suggested that the contaminated lake water outflows directly effect meiobenthos in a relatively short time period and thus the meiobenthos may be a good indicator animal group for examining the effect of pollution.

Methane Recovery from NaCl Inhibition of Food Waste Anaerobic Digestion

( Jae Hac Ko ),( Danling Xia ),( Qiyong Xu ) 한국폐기물자원순환학회(구 한국폐기물학회) 2020 한국폐기물자원순환학회 추계학술발표논문집 Vol.2020 No.-

One of the big challenges of food waste anaerobic digestion is the inhibition of high NaCl concentrations. This study investigated the effects of NaCl fluctuation on the methane generation of food waste anaerobic digestion under both thermophilic and mesophilic conditions, especially focusing on shock loading of high NaCl concentration with/without water dilution treatment. In general, methane generation decreased with increasing the concentration of NaCl concentrations. Thermophilic AD was more sensitive to NaCl concentration change at the range of 5-10 g/L. When NaCl concentration increased from 0 g/L to 30 g/L, the accumulative methane volumes of thermophilic and mesophilic reactors decreased from 420 mL to 133 mL and from 529 mL to 133 mL, respectively. With increasing NaCl concentration, pH of digestate decreased while COD and VFA concentrations increased. Results indicated that a shock-loading of NaCl significantly reduced methane generation. Using water dilution as a remedial measure, the methane generation rates could be recovered up to 64% - 72%. Further investigation with 16S rRNA analysis showed that the predominant genus of methanogens shifted from Methanoculleus to Methanosarcina after removal of osmotic stress by water dilution.

Municipal Solid Waste Degradation and Compaction

( Jae Hac Ko ),( Mingying Li ),( Fan Yang ),( Qiyong Xu ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-

This study investigated the impact of compaction on anaerobic degradation of municipal solid waste (MSW) during the phase of methane formation. Two stainless steel lysimeters were constructed with equipped a hydraulic cylinder to apply pressure load on the MSW. When methane production rates decreased from the peak rate of each column, pressure load was applied at different degrees of decomposition (DOD). When pressure load was applied, chemical oxygen demand (COD) showed temporary increases, Methane production rate also increased by the compaction. However, the impact of compaction on methane production rate varied with different degrees of decomposition. MSW compaction reduced pore space of MSW resulting in increasing the contact surface area of among MSW particles. It was thought that the mass transfer of volatile fatty acids could be enhanced by increased contact surface area and degree of saturation as the consequence of the compaction.

The First Record of the Pectinariid Polychaete Amphictene japonica (Nilsson) in Korea

Hong, Jae-Sang,Frey, Robert W.,Lee, Jae-Hac The Korean Society for Integrative Biology 1989 동물학회지 Vol.32 No.1

A study of benthic populations on a tidal flat near Inchon has revealed the presence of Amphictene japonica (Nilsson) a large pectinariid polychaete worm not previously documented in Korean waters. Near Inchon it is apparently restricted to silty sands or sandy silts along seaward parts of the intertidal flat. In addition to its large size, A. japonica is distinguished from other pectinariids by means of (1) the posterior rim of the cephalic plaque, which bears 20 to 25 marginal denticulations, and (2) the scaphal hooks, which number 19 to 24 on either side. 인천의 인근지역인 척전 조간대 사니질 간척지의 해양저서생물의 생태학적 연구를 위한 조사 과정에서 이 지역 조간대 하부의 사니질 구역에서 한국 미기록종인 대형 빗갯지렁이를 발견하였기에 그 형태적 기재와 추적학적 의의를 고찰하였다. 긴빗갯지렁이는 지금까지 보고된 빗갯지렁이류에 비하여 대형인 것이 특징이며 그 밖에도 (1) 머리부분의 등쪽 뒷편에 약 20-25개의 톱니모양의 막으로 연결되어 있으며, (2) 꼬리판 위에 좌우로 19-24개의 갈고리 모양의 가시를 갖는다.

Taxonomical Review of Perinereis aibuhitensis Grube, 1878 (Nereidae: Polychaeta) in Korea

Lee, Jae-Hac(이재학),Je, Jong-Geel(제종길),Choi, Jin-Woo(최진우) 한국동물분류학회 1992 Animal Systematics, Evolution and Diversity Vol.8 No.1

인천연안역 저서동물의 종조성을 이용한 환경평가

이재학(Jae Hac Lee),고병설(Byoung Seol Koh),박흥식(Heung Sik Park) 한국수산과학회 1997 한국수산과학회지 Vol.30 No.5

In order to select an effective and appropriate evaluation method for the marine environmental protection and management, it is necessary to evaluate the present status of environmental conditions and to monitor and regulate the harzadous waste continuously. Among the evaluation methods that use benthic fauna, some graphical methods and biological index methods such as species abundance-biomass(SAB), Rank-frequency diagram(RFD), Abundance-Biomass comparison(ABC), Log-normal distribution(LND), and Benthic Pollution Index(BPI) modified by Infaunal Trophic Index were used for the assessments of marine environment in the Inchon coastal area. Even though the graphic methods are convenient for easy glimpse of general trend of environmental condition but because they require sufficient ecological data, those methods do not fit for analysis or comparison of regional and detailed environmental condition. On the other hand, when BPI was applied, it was able to compare the spatial benthic conditions. Through considering the functional aspects of benthic fauna which can not be obtained in the cluster analysis, BPI was made it possible to measure or trace down the source of pollution. In the case of the environmental assessment result analyzed in Inchon coastal area, the north eastern part of Yongjongdo was more influenced by the pollution than the outer area of Inchon. The research indicates that especially Inchon harbor has been greatly affected.

이원방조제 주변의 조간대 및 조하대 대형저서동물의 군집과 환경요인과의 관계

이재학 ( Jae Hac Lee ),유옥환 ( Ok Hwan Yu ),이형곤 ( Hyung Gon Lee ),박자양 ( Ja Yang Park ) 한국수산과학회 2004 한국수산과학회지 Vol.37 No.4

N/A Spatial patterns in the macrobenthic community structure in the inter- and subtidal zones in front of the Iwon Dike and environmental variables were examined in August 2001. In total, 156 macrobenthic species (123 intertidal species and 90 subtidal species) were recorded during this study, predominately polychaetes (40%), bivalves (22%), and crustaceans (22%). Polychaetes made up less than 40% of the intertidal community, but more than 50% of the subtidal community. The mean density during this study was 1,456 ind./m . Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among four regions: near the Iwon dike (B1), the high and middle intertidal zone (B2), low intertidal zone (Al), and subtidal zone (A2). The number of species, total density, and diversity (H`) varied significantly among the four regions. The distribution of macrobenthic community was affected by environmental variables, such as % silt/clay content, total sulfide, lose of ignition, and chemical oxygen demand. These environmental variables were negatively correlated with the dominant species (Nephtys polybranchia, Umbonium thomasi, and Scoloplos armiger) in the intertidal area, but positively correlated with the dominant species (Lumbrineris cruzensis, Notomastus latericeus, and Moerella sp.) in the subtidal area. Environmental variables (% silt/clay content and total sulfide) were positively correlated with the dominant species (Heteromastus filiformis) in region B1, but negatively correlated with the dominant species (Umbonium thomasi and Scoloplos koreanus) in region B2. Amphipods Urothoe spp. and Monoculodes koreanus were the dominant species in region Al. Umbonium thomasi, the dominant species in region B2, was not found in regions B1 or Al. We suggest that the inter-specific competition for territory and exposure to seawater may be important factors controlling the macrobenthic community structure in the inter- and subtidal zones in front of the Iwon Dike.