• The Journal of Engineering Geology
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• v.26 no.4
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• pp.583-591
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• 2016

Vibrating wire (VW) strain gauges are widely used for the evaluation of pipeline safety in extreme cold region. The development of VW strain gauges for the low temperature environment is necessary because of the high cost of gauges sold in developed countries. Thermistors embedded in the regular VW strain gauges and PT 100 sensors embedded in the gauges specially manufactured for this study have gone through credibility tests for temperature measurements. The use of PT 100 is recommended at low temperature environments because thermistors have low credibility at temperatures below $-15^{\circ}C$. Strain measurements using regular VW strain gauges also show low accuracies as temperature goes down. VW strain gauges manufactured using inconel give high credibility of strain measurements at low temperatures. More reliable VW strain gauges for the low temperature environment will be developed in the near future.

• Spatial Information Research
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• v.20 no.6
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• pp.129-137
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• 2012

For construction project in extreme cold region, it is essential to establish basic data on the site such as topographical data from the early stage of construction of planning and designing, and it is needed to frequently perform site investigation when necessary. However, extreme cold regions are characteristic of being at long distance and difficult in approaching, and special regions such as Antarctica, in particular, are hard to conduct site investigation. Although a site investigation may be conducted, those who can visit Antarctica are sufficiently limited so that most of the staff may participate in construction without knowledge of the site and increase the risk of errors in decision making or designing. In order to resolve such problems, the authors in this study identified methods of building wide-area topographical data and bedrock classification data of exposed areas via remote sensing and of building precise topographical data on the construction site. Also, the authors attempted to present methods by which such data can be managed and visualized integrally via three-dimensional GIS technology and all the participants in construction can learn sense of field and conduct necessary analysis as frequent as possible. The areas around the Jangbogo Antarctic Station were selected to be the research area for conducting effective integrational management and three-dimensional visualization of various spatial data such as wide-area digital elevation model, ortho-images, bedrock classification data, local precise digital elevation model, and site images. The results of this study may enable construction firms to analyze local environments for construction whenever they need for construction in extreme cold regions and then support construction work including decision making or designing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.271-279
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• 2019

In extreme environment regions, unmanned rovers equipped with various sensors and devices are being developed for long-term exploration on behalf of humans. On the other hand, due to the harsh weather conditions and rough terrain, the rover camera has limited visible distance and field of view. Therefore, the rover cameras should be located for safe navigation and efficient terrain mapping. In this regard, to minimize the cost and time to manufacture the camera system on a rover, the simulation method using the rover design is presented to optimize the camera locations on the rover efficiently. In the simulation, a simulated terrain was taken from cameras with different locations and angles. The visible distance and overlapped extent of camera images, and terrain data accuracy calculated from the simulation were compared to determine the optimal locations of the rover's cameras. The simulated results will be used to manufacture a rover and camera system. In addition, self and system calibrations will be conducted to calculate the accurate position of the camera system on the rover.

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.519-527
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• 2021

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.

• Ocean and Polar Research
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• v.36 no.3
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• pp.303-318
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• 2014

The rising global demand for energy resources may lead to greater interest in the Arctic region. Since it has various resources, such as oil and gas, and large potential as a strategic location in exploration and production (E&P), there is likely to occur island sovereignty issues between the five arctic costal states and other countries. While global warming has led to the opening of the Northeast Passage and the Northwest Passage, several obstacles may impede the development of this area such as the low temperature environment, infrastructure problems in a limited area, flow assurance, environmental regulations, etc. To overcome these problems, various techniques have been applied in the exploration, development, production, transportation, and environment fields and it seems to be made technical development in extreme environment. In this study, the E&P status of representative states and development technologies in the Arctic region have been summarized with regard to carrying out E&P related to drilling, development, production, and operation in oil and gas fields. Furthermore, environmental factors have been taken into account to enhance progress with regard to E&P and ensure sustainable development in the Arctic. On that basis, it will be possible to secure oil and gas field development, production technology and R&D infrastructure in the Arctic.

• KIEAE Journal
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• v.5 no.2
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• pp.19-26
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• 2005

Every site has a different given geometrical and climatic condition, which influenced not only the lifestyle of the humanbeings but also the regional architecture. For example, on a cold region, the reduction of the energy loss is necessary, like an igloo, which has a littlest energy loss at hemisphere. Or on a warm region, the house must be protected thermally from the overheating at the sunshining. like a huge shading. An architectural interpretation in the (extreme) moderate climate, like Korea, has always tried to satisfy the both opposite demands simultaneously. A facade, which divides out- and inside, has an ideal position to lead the regulated regional climatic conditions into the room. The Double Facade System(DFS) is well known as an innovative solution in the european countries, like Germany. It provides an reasonable alternative, which can achieve these goals at the same time. A Double Facade System provides an effective sunshade, which means a cooling energy reduction at the warm season. In addition, it enables a natural ventilation at the cold season with the preheating at the system as well as spring and autumn. An ordinary Single Facade System with a inside or outside sun blind provides a solution just for a specified season, like a summer or winter. But the Double Facade System can deal with the various climatic conditions in the moderate climate.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.54-58
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• 2011

According to the Fourth Assessment Report of the Inter governmental Panel on Climate Change(IPCC), climate change is already in progress around the world, and it is necessary to start mitigation and adaptation strategies for buildings in order to minimize adverse impacts. It is likely that the South Korea will experience milder winters and hotter and more extreme summers. Those changes will impact on building performance, particularly with regard to cooling and ventilation, with implications for the quality of the indoor environment, energy consumption and carbon emissions. This study generate weather data for future climate change for use in impacts studies using PRECIS (Providing REgional Climate for Impacts Studies). These scenarios and RCM (Regional Climate Model) are provided high-resolution climate-change predictions for a region generally consistent with the continental-scale climate changes predicted in the GCM (Global Climate Model).

• Atmosphere
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• v.31 no.4
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• pp.433-443
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• 2021

The wind speed and wind direction in Yeongdong are one of the crucial meteorological factors for forecasting snowfall in this area. To improve the snowfall forecast in Yeongdong region, Yeongdong Extreme Snowfall-Windstorm Experiment, YES-WEX was designed. We examined the wind field variation simulated with Local Data Assimilation and Prediction System (LDAPS) using observed wind field during YES-WEX period. The simulated wind speed was overestimated over the East Sea and especially 2 to 4 times in the coastal line. The vertical wind in Yeongdong region, which is a crucial factor in the snowfall forecast, was not well simulated at the low level (850 hPa~1000 hPa) until 12 hours before the forecast. The snowfall distribution was also not accurately simulated. Three hours after the snowfall on the East Sea coast was observed, the snowfall was simulated. To improve the forecast accuracy of snowfall in Yeongdong region, it is important to understand the weather conditions using the observed and simulated data. In the future, data in the northern part of the East Sea and the mountain slope of Taebaek observed from the meteorological aircraft, ship, and drone would help in understanding the snowfall phenomenon and improving forecasts.

• The KSFM Journal of Fluid Machinery
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• v.19 no.3
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• pp.37-42
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• 2016

The demand for wireless technology in plant structure has recently been increasing due to several advantages such as installation cost reduction, easy placement, easy extension and aesthetic benefits. Among the many wireless technologies, ZigBee is one of the most useful for plant structure; a wireless plant networking system can be configured using ZigBee alone. This research proposes a ZigBee to use for extreme cold region and thereby enable integration of wired and wireless plant monitoring systems. In this study, in order to assess the performance of ZigBee measured data by thermocouple were examined based on the results from laboratory tests between existing ZigBee and developed ZigBee. From the experiment results, performance of developed ZigBee in harsh environment can be increased well.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.213-225
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• 2020

Floating Offshore Wind Turbines (FOWT) installed in the deep sea regions where stable and strong wind flows are abundant would have significantly improved energy production capacity. When designing FOWT, it is essential to understand the stability and motion performance of the floater. Water tank model tests are required to evaluate these aspects of performance. This paper describes a model test and numerical simulation for a 750-kW semi-submersible platform wind turbine model-II. In the previous model test, the 750-kW FOWT model-I suffered slamming phenomena from extreme wave conditions. Because of that, the platform freeboard of model-II was increased to mitigate the slamming load on the platform deck structure in extreme conditions. Also, the model-I pitch Response Amplitude Operators (RAO) of simulation had strong responses to the natural frequency region. Thus, the hub height of model-II was decreased to reduce the pitch resonance responses from the low-frequency response of the system. Like the model-I, 750-kW FOWT model-II was built with a 1/40 scale ratio. Furthermore, the experiments to evaluate the performance characteristics of the model-II wind turbine were executed at the same location and in the same environment conditions as were those of model-I. These tests included a free decay test, and tests of regular and irregular wave conditions. Both the experimental and simulation conditions considered the blade rotating effect due to the wind. The results of the model tests were compared with the numerical simulations of the FOWT using FAST (Fatigue, Aerodynamics, Structures, and Turbulence) code from the National Renewable Energy Laboratory (NREL).