• Monthly Duck's Village
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• s.81
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• pp.54-60
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• 2010

2006년 기준으로 1천8백만 수수의 육용오리가 사육되고 있는 영국에서는 오리 사육시 복지적인 측면에서의 생산 시스템에 대하여 여러 의견이 나오고 있다. 자연에서 물과 오리의 상관관계에도 불구하고, 오리가 몸을 담그거나 헤엄칠 수 있는 등 활동에 필요한 물을 제공해야한다는 어떠한 법적 규제도 마련되어 있지 않다. 어떤 경우에는 오리들이 머리를 물에 담글 수 있게 트러프(홈통형 물통)을 제공하기도 하지만 어떤 경우에는 니플 급수기를 통해서만 물에 접근할 수 있기도 하다. 유럽평의회는 오리들이 머리를 담그고 깃털을 적실 수 있는 형태로 물을 제공할 것을 권장한다. 우리는 이번 연구에서 오리의 복지가 자연 및 물의 접근 허용 점위와 관련이 있다는 것을 밝히고자 오리의 몸과 깃털 상태를 기록하는 한편, 물 제공에 따른 복지 수준을 평가하기 위해 3자기 행동 평가를 하였다. 오리들은 욕조(작은 연못), 트러프, 샤워시설, 니플급수기, 5주령까지 니플 급수기만 제공하고 이후 욕조를 이용하는 등의 5가지 방법으로 물에 접근할 수 있도록 하였고, 이는 1)한 시설에서 오리가 보내는 시간, 2)욕조가 주어졌을 때 오리들의 보상행동, 3) 오리들이 가장 선호하는 시설을 기록하여 오리의 행동을 평가하였다. 이를 통해 오리들이 머리를 담그고 깃털을 정리할 수 있는 물을 제공하지 않으면 오리들이 코나 깃털을 깨끗이 유지할 수 없다는 결론을 얻을 수 있었다. 중요한 것은 욕조, 트러프, 샤워기를 통해 물을 제공해 주었을 때 물에서 목욕(bathing)을 하며 보낸 시간은 모두 동일하였다는 사실이다. 그러나 니플 급수기에서 목욕행동(bathing movement)을 한 시간은 아주 짧았으며, 니플 급수기 만으로 사육되었던 오리군의 욕조시설을 제공하였을 때는 '보상 반등행동'을 보였다. 트러프나 샤워시설이 제공되었던 그룹에서는 보상행동을 보이지 않아 이러한 시설들이 욕조와 동일한 작용을 하는 것으로 볼 수 있다. 또, 오리들에게 선택권이 주어졌을 때 오리들은 욕조에서 헤엄을 치고, 샤워시설에서 물을 마시고 장난치는 것을 선호하는 것으로 나타났다. 다른 시설들이 제공되었을 때 오리들은 니플 급수기에서 거의 시간을 보내지 않았다. 이번 연구를 통하여 육용 오리의 사육 환경의 복지 개선을 위해 트러프나 샤워 시설로 실제 욕조(작은 연못) 만큼 긍정적인 효과를 얻음을 확인 할 수 있었다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.3
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• pp.268-276
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• 2008

Potential tsunamis generated in Okinawa Trough were simulated for the investigation of the propagation characteristics in the southwestern sea of Korean Peninsula. Shallow waters in the continental shelf of East China Sea and deep waters in Okinawa Trough play an important role in the propagation characteristics of the tsunamis generated in this region. The propagation characteristics can be classified into two phases according to the stage of propagation. In the first phase, the tsunamis propagate both northeast and southwest along the deep water of the trough. In the second phase, the tsunamis enter the continental shelf of the East China Sea at right angles to topographic contour lines. Simulated results show that the tsunamis generated in the Okinawa Trough give a weak influence to the southern and western coasts of Korea due to the special topography of the southwestern sea of Korean Peninsula.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.415-417
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• 2007

• Economic and Environmental Geology
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• v.36 no.6
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• pp.491-499
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• 2003

The Okinawa Trough is a rift basin formed by extension. Analysis of multichannel seismic reflection profiles from the northwestern margin of the northern Okinawa Trough reveal that the trough is characterized by a series of tilted fault blocks bounded by listric normal faults and half-grabens developed between blocks, showing typical rifted structures. The trough display three kinds of sedimentary sequences with different seismic reflection characteristics: prerift, synrift and postrift sediments. The prerift sequence develops parallel to the dip direction of tilted fault blocks. The synrift sediments, mostly deposited in the half-grabens between tilted fault blocks, are generally well characterized by divergence of the reflectors towards the blocks indicating contemporaneous deposition during tilting. The postrift sediments are featured by continuous and parallel reflectors. The width of the half-graben and the throw-displacement rate of the basin bounding fault are closely connected. The throw-displacement rate is the maximum when the rifting event is the most active and the width of the half-graben is proportional to the rate.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.543-554
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• 2004

Analysis of multi-channel seismic reflection and well data serves to detail the structural evolution of the northern Okinawa Trough, southern offshore Korea. The overall structural style of the area is characterized by a series of half grabens and tilted fault blocks bounded by basement-involved listric normal faults. Most half grabens and tilted fault blocks developed in the direction of NNE-SSW, parallel to the axis of the Okinawa Trough. Orientation and distribution of the listric faults also suggest the development of transfer faults in NW-SE direction. The rifting phase of the northern Okinawa Trough have been established on the basis of structural and stratigraphic analyses of depositional sequences and their seismic expressions. Major phase of rifting probably started in the Late Miocene and the most active rifting occurred during the Early Pliocene. The rifting produced a series of half grabens and tilted fault blocks bounded by listric normal faults. It appears that the rifting activity has become weaker since the Late Pliocene, but the Pleistocene sediments faulted by listric faults bounding tilted fault blocks suggest that the rifting activity is probably still in progress.

• NEWSLETTER 전기공업
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• no.94-4 s.101
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• pp.16-40
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• 1994

• Tunnel and Underground Space
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• v.23 no.1
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• pp.31-41
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• 2013

Graphical method has been widely applied to the prediction of subsidence area, and is known to have advantages in analysis of trough subsidence which is common in horizontally seamed mine area. However, it is reported that most of the ore bodies in Korea are geologically inclined from sub-horizontal to steep, and therefore, the sinkhole subsidence is frequent in abandoned mine area. For these reasons, it is not to be desired that graphical method is applied for predicting the subsidence occurrence. This paper describes the results of subsidence zone prediction considering the dip direction and the opposite direction of inclined ore bodies from the case studies on the 163 subsidence occurrence regions. The results show also the assumed angle which can define the range of subsidence in the surface area. In conclusion, the limit of this angle is suggested after taking into account the comparison with graphical method and the application to the case histories.

• Geophysics and Geophysical Exploration
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• v.10 no.1
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• pp.29-36
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• 2007

Recent seismic surveys have shown that the presence of methane hydrate (MH) in sediments has significant influence on seismic attenuation. I have used vertical seismic profile (VSP) data from a Nankai Trough exploratory well, offshore Tokai in central Japan, to estimate compressional attenuation in MH-bearing sediments at seismic frequencies of 30-110 Hz. The use of two different measurement methods (spectral ratio and centroid frequency shift methods) provides an opportunity to validate the attenuation measurements. The sensitivity of attenuation analyses to different depth intervals, borehole irregularities, and different frequency ranges was also examined to validate the stability of attenuation estimation. I found no significant compressional attenuation in MH-bearing sediments at seismic frequencies. Macroscopically, the peaks of highest attenuation in the seismic frequency range correspond to low-saturation gas zones. In contrast, high compressional attenuation zones in the sonic frequency range (10-20 kHz) are associated with the presence of methane hydrates at the same well locations. Thus, this study demonstrated the frequency-dependence of attenuation in MH-bearing sediments; MH-bearing sediments cause attenuation in the sonic frequency range rather than the seismic frequency range As a possible reason why seismic frequencies in the 30-110 Hz range were not affected in MH-bearing sediments, I point out the effect of thin layering of MH-bearing zones.

• Geophysics and Geophysical Exploration
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• v.10 no.1
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• pp.37-43
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• 2007

The MH21 Research Consortium has conducted a high-resolution 3D seismic survey and a seafloor geochemical survey, to explore methane hydrate reservoirs in the eastern Nankai Trough, offshore Japan. Excellent geological information about shallow formations was obtained from the high-resolution 3D seismic survey, which was designed to image the shallow formations where methane hydrates exist. The information is useful in constructing a geological and geochemical model, and especially to understand the complex geology of seafloor, including geochemical manifestations and the structure of migration conduits for methane gas or methane-bearing fluid. By comparing methane seep sites observed by submersibles with seismic sections, some significant relationships between methane hydrate reservoirs, free gas accumulations below the seafloor, and seafloor manifestations are recognised. Bathymetric charts and seafloor reflection amplitude maps, constructed from seismic reflections from the seafloor, are also useful in understanding the relationships over a vast area. A new geochemical seafloor survey targeted by these maps is required. The relationships between methane hydrate reservoirs and seafloor manifestations are becoming clearer from interpretation of high-resolution 3D seismic data. The MH21 Research Consortium will continue to conduct seafloor geochemical surveys based on the geological and geochemical model constructed from high-resolution 3D seismic data analysis. In this paper, we introduce a basis for exploration of methane hydrate reservoirs in Japan by fusion of 3D seismic exploration and seafloor geochemical surveys.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.887-894
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• 2000

The purposes of this study are investigation of species of attached algae and the relation between attached algae and odor in tap water, Oscillatoria sp. and Mougeotia sp. were colonized at sedimentation basin in water treatment plant. Resulting from analysis, 3.7ppt of geosmin and dimethyl-disulfide with trace were detected in sample of Oscillatoria sp. only, 22 compounds were found in each of sample that had been incubated in room temperature for 5 days, 17 compounds were generated by algal decay. Decayed products were sulfur compounds of 10 species such as dimethyl-sulfide and phenol, p-cresol, indole and scatole. So, it is assumed that attached algae which tolerant to chlorine was the origin of odor in tap water. They usually formed big colonies. Colonies on the bottom were decayed because of anaerobic state. While decaying they were detached from colonies and so, odorous compounds are originated from this decayed algae.