• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.691-700
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• 2019

Objective: This study was conducted to assess increasing doses of phytase added to broiler diets formulated with different levels of available phosphorus (avP), calcium (Ca), and sodium (Na), and the respective effects on performance parameters, quantitative carcass characteristics, ash and phosphorus deposition in tibia and weight of organs. Methods: Three different matrices were assumed for phytase with the following nutritional values: matrix A (MT A): 0.165% Ca, 0.150% avP, and 0.035% Na; matrix B (MT B): 0.215% Ca, 0.195% avP, and 0.045% Na; matrix C (MT C): 0.245% Ca, 0.225% avP, and 0.053% Na. There were six different diets: No phytase (formulated to meet the nutritional requirements); phytase 500 FTU/kg+MT A; phytase 1,000 FTU/kg+MT A; phytase 1,500 FTU/kg+MT A; phytase 1,000 FTU/kg+MT B and phytase 1,500 FTU/kg+MT C. Results: There was no significant phytase influence on performance, quantitative carcass characteristics, ash and phosphorus deposition in tibia and weight of the organ throughout the study period, however, it was possible to observe a tendency of improvement in body weight corrected feed conversion for broilers fed the phytase 1,500+MT C diet, where potentially these birds were more efficient on utilize phytic phosphorus and other nutrients bounded to phytate molecule, translating into improvement in performance, and there was also a non significant numerical improvement in body weight corrected feed conversion of broilers fed this diet. Conclusion: Broilers fed with diets formulated with different levels of avP, Ca, and Na and increasing doses of phytase have shown no change on performance, quantitative carcass characteristics, ash and phosphorus deposition in tibia and weight of organs.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.35-48
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• 2021

The Gumi basin, situated in the mid-southeastern Yeongnam Massif, has the Cretaceous stratigraphy that is divided into Gumi Formation, andesitic rocks (Yeongamsan Tuff, Busangni Andesite), rhyolitic rocks (Obongni Tuff, Doseongul Rhyolite, Geumosan Tuff) and Intrusives (ring dikes, other dikes) in ascending order. The Geumosan Tuff is composed mostly of many ash-flow tuffs which are associated with Geumosan caldera along with the ring dikes. The caldera is outlined by ring faults and dikes and has about 3.5 × 5.6 km in diameters. The intracaldera volcanics show a downsag structure that is dipped inward in their flow and welding foliations. The caldera block represent an asymmetric subsidence, which drops 350 m in the northern margin and 600 m in the southern one. Based on these data, the Geumosan caldera is geometrically classified as an asymmetric piston subsidence caldera that suggests a single caldera cycle. The caldera reflects the piston subsidence of the caldera block bounded by the outward-dipping ring faults following a voluminous eruption of magma from the chamber. The downsag in the caldera block refers to the downsagging during the initial subsidence at the same time as the full development of the bound fault. In the ring fissures following the sagging, magma was injected due to the overpressure of magma chamber caused by subsidence.

• Korean Journal of Environment and Ecology
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• v.36 no.2
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• pp.202-216
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• 2022

Animals exhibit certain behaviors and movement patterns as they react to their internal needs, external stimuli, and surrounding environments. They have a bounded range in which they mostly spend their time, and it is referred to as a home range. Based on the fact that the home range is a critical area for the survival and preservation of species, there has been a growing body of research on developing more precise home range estimation methods to use the estimated ranges as a ground for establishing an effective conservation policy since the early 1940s. Recent rapid advancements in telemetry technology that resulted in the presence of autocorrelation between locations with short time intervals revealed the limitations of the existing estimators. Many novel estimators have been developed to compensate for it by incorporating autocorrelation in calculating home ranges. However, studies on the animal home range are still in their early stage in Korea, and newly developed methodologies have not yet been adopted. Therefore, this study aims to introduce the foreign home range estimation methods and foster domestic research activities on home ranges. Firstly, we compared and contemplated seven estimators by categorizing them into geometrical and statistical methodologies and then divided them into estimators that assume independent observations and those that consider autocorrelation in each category. After that, the home ranges of black-tailed gulls (Larus crassirostris) were calculated using GPS tracking data for the month of June and derived home range estimators by applying the methodology introduced in this study. We analyzed and compared the results to discuss the strengths and weaknesses of each method. Lastly, we proposed a guideline that can help researchers choose an appropriate estimator for home range calculation based on the animal location data characteristics and analysis purpose.

• Journal of the Korean Regional Science Association
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• v.38 no.1
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• pp.45-56
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• 2022

The purpose of this study is to examine the differences among the income level groups of young single-person households and newlywed households in factors affecting the choice of residential location in the Seoul metropolitan region. To summarize the results of the analysis, first, there were differences in the factors affecting the choice of residential location by income level in both single-person young households and newlyweds. Second, among young households, the low-income group showed a behavior of choosing a residential location based on bounded rationality considering the economic condition of the household. Third, even though the income level is similar, the difference in the factors for choosing a residential location between single-person young households and newlywed households was confirmed, which is results of the life-cycle changes. These results imply that it is necessary to prepare appropriate housing policies that can supplement the economic conditions of young households living in the Seoul metropolitan region, and to review customized housing policies that reflect changes in life-cycle stages as well as age or income level.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.239-246
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• 2021

Unification means the change of the economic system from 'Planned Economy' of the North Korea to 'Market Economy' of the South Korea. Therefore, it may cause confusions and difficulties for North Koreans who have been under planned economy for ages. So, we need to take the perspective of behavioral economics for the effective education. First of all, it is about overall finance, which contains the record of financial transactions, effect of inflation, investors' bounded rationality, and choice difficulty of financial products. Second, it is about borrowings, which includes the credit management, interest rate of difference among financial institutions. Third, it is about investment on financial products, which includes the effect of cost on returns, difference between compound interest and simple interest, trade-off between expected return and risk, market and non-market risks, the importance of diversification, and passive & aggressive investments.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.111-123
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• 2023

The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m³ formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

• 한국노년학
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• v.29 no.1
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• pp.177-194
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• 2009

Korea government has launched long-term care insurance from 2008. However, one of the most important issues, whether or not providing cash benefit, is still unresolved. In this paper, in order to provide policy guidelines for the long-term care insurance, I attempt to estimate the Willingness-To-Accept (WTA) of the cash subsidy for informal care by using Double Bounded Dichotomous Choice method, a branch of Contingent Valuation Method (CVM). In doing so, I also estimated the determinants of the preference for cash benefit. Data were obtained from face-to-face survey interviews with 300 informal care-givers at three major general hospitals in Seoul, Korea. The questionnaire was constructed with two scenarios (mild/severe symptom). The results from logistic regression analyses and the estimation of WTA indicate that informal care-givers are willing to accept the cash benefit as low as 628 thousands won for mild fragile elderly and 1,072 thousands won for severe fragile elderly. The strength of this paper is that I estimated the WTA of the cash benefit by reflecting the changes in preferences of informal care-givers. The analytic results from the this paper suggest that the cash benefit in long-term care insurance is indispensible in achieving the goal of the long-term care system.

• Economic and Environmental Geology
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• v.2 no.4
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• pp.73-90
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• 1969

The area studied is a southwestern part of Okcheon geosynclinal zone which streches diagonally across the Korean peninsula in the mid-central parts of South Korea, and is bounded by Charyeong mountain chains in the north and by Sobaek mountain chains in the south. The general trend of the zone is of NE-SW direction known as Sinian direction. Okcheon system of pre-Cambrian age occupies southwestern portion of Okcheon geosynclinal zone, and Choseon and Pyeongan systems of Cambrian to Triassic age in northeastern portion of the zone. It was defined by the writer that the former was called "Okcheon Paleogeosynclinal zone" and the latter "Okcheon Neogeosynclinal zone," although T. Kobayashi named them "Metamorphosed Okcheon zone" and "Non-metamorphosed Okcheon zone" respectively and thought that sedimentary formations in both zones were same in origin and of Paleozonic age, and C.M. Son also described that Okchon system was of post-Choseon (Ordovician) and pre-Kyeongsang (Cretaceous) in age. According to the present study two zones are separated by great fault so that the geology in both zones is not only entirely different in origin and age, but also their geolosical structures are discontinuous. Stratigraphy and structure of Okcheon system are clearly established and defined by the writer and its age is definitely pre-Cambrian. It is clarified by present study that the meta-sediments in and at vicinity of Charyeong mountain chains are correlated to Weonnam series of pre-Cambrian age which occupies and continues from northeast to southwest in and at south of Sobaek mountain chains, and both metasediments constitute basement of Okcheon system. Pyeongan, Daedong and Kyeongsang systems were deposited in few narrow intermontain basins in Okcheon paleogeosynclinal zone after it was emerged at the end of Carboniferous period. Granites of Jurassic and Cretaceous ages and volcanics of Cretaceous age are cropped out in the zone. Jurassic granite is aligned generally with the trend of Okcheon geosynclinal zone, whereas Cretaceous granite lacks of trend in distribution. Many isoclinal folds and thrust faults caused by Taebo orogeny at the end of Jurassic period are also parallel with Sinian directieon and dip steeply to northwest. Charyeong, Noryeong, Sobaek, and Deogyu mountain chains are located in areas of anticlinorium, and Kyongsang system in narrow synclinal zones. Folds in Okcheon neogeosynclinal zone are generally of N 70-80W direction but deviate to Sinian direction at the western parts of the zone. This phenomena is interpreted by the fact that the folds were originated by Songrim disturbance at the end of Triassic period and later partly modified by Taebo orogeny. Thrust faults of Taebo orogeny coentinue from Okcheon paleogeosynclinal zone into neogeosynclinal zone, forming imbricated structure as previously described. Strike-slip faults perpendicular to Sinian direction and shear faults diagonally across it by 55 degrees also prevail in neogeosynclinal zone. It is concluded from viewpoints on geology and geological structure that l)Okchon geosyncline had changed its location and affected by numerous disturbances through geologic time, and 2)mountain chains in the area such as Charyeong, Noryeong, Sobaek, and Deogyu were originated as folded mountains. Differing from others, however, Sobaek range was probably formed at the time of Songrim disturbance and modified later by Taebo orogeny. It is cut by Danyang-Jeomchon fault at the vicinity of Joryeong near Munkyeong village and does not continue to southwest beyond the fault, whereas southwestern portion of erstwhile Sobaek range continues to Taebaek rangd northeastward from Deogyusan passing through Sangju, Yecheon, and Andong. From these evidences, the writer has newly defined the erstwhile Sobaek range in such a way that Sobaek range is restricted only to northeastern portion and Deogyu range is named for the southwestern portion of previous Bobaek range.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.153-171
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• 2018

This study focuses on the investigation of geologic distribution and stratigraphy in the eastern part of Yeongdeok-gun, based on Lidar imaging, detailed field survey, microscopic observations, SHRIMP and LA-MC-ICPMS U-Pb age dating, and a new geological map has been created. The stratigraphy of the study area is composed of the Paleoproterozoic metamorphic rocks consisting of banded gneisses of sedimentary origin and schists ($1841.5{\pm}9.6Ma$) of volcanic origin, Triassic Yeongdeok plutonic rocks ($249.1{\pm}2.3Ma$) and Pinkish granites ($242.4{\pm}2.4Ma$), Jurassic Changpo plutonic rocks ($193.2{\pm}1.9Ma{\sim}188.8{\pm}2.0Ma$) and Fine-grained granites ($192.9{\pm}1.7Ma$), Formations [Gyeongjeongdong Fm, Ullyeonsan Fm. (~108 Ma), Donghwachi Fm.] of the Early Cretaceous Gyeongsang Supergroup and acidic volcanic rocks and dykes erupted and intruded in the Late Cretaceous, Miocene intrusive rhyolitic tuffs ($23.1{\pm}0.2Ma{\sim}22.97{\pm}0.13Ma$) and sedimentary rocks of the Yeonghae basin, and the Quaternary sediments. The Triassic Pinkish granites, Jurassic Changpo plutonic rocks and Fine-grained granites are newly defined plutonic rocks in this study. Miocene intrusive rhyolitic tuffs bounded by the Yangsan Fault, which was first discovered in the north of Pohang city, are believed to play an important role in the understanding of the Miocene volcanic activity and the crustal deformation history on the Korean Peninsula. It is confirmed that The NNE-SSW-striking Yangsan Fault penetrating the central part of the study area and branch faults are predominant in the dextral movement and cutting all strata except the Quaternary sediments.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.541-554
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• 2019

The Taebaeksan Zone of the Okcheon Belt is a prominent fold-thrust belt, preserving evidence for overlapped polyphase and diachronous orogenic events during crustal evolution of the Korean Peninsula. The Pyeongchang-Jeongseon area of the northwestern Taebaeksan Zone is fault-bounded on the western Jucheon and southern Yeongwol areas, showing lateral variations in stratigraphy and structural geometries. For better understanding these geological characteristics of the northwestern Taebaeksan Zone, we have studied the structural geometry of the Pyeongchang-Jeongseon area. For this, we have firstly carried out the SHRIMP U-Pb age analysis of the age-unknown sedimentary rock to clarify stratigraphy for structural interpretation. The results show the late Carboniferous to middle Permian dates, indicating that it is correlated to the Upper Paleozoic Pyeongan Supergroup. In addition to this, we interpreted the geometric relationships between structural elements from the detailed field investigation of the study area. The major structure of the northwestern Taebaeksan Zone is the regional-scale Jeongseon Great syncline, having NE-trending hinge with second-order folds such as the Jidongri and Imhari anticlines and the Nambyeongsan syncline. Based on the stereographic and down-plunge projections of the structureal elements, the structural geometry of the Jeongseon Great syncline can be interpreted as a synformal culmination, plunging slightly to the south at its southern area, and north at the northern area. The different map patterns of the northern and southern parts of the study area should be resulted in different erosion levels caused by the plunging hinges. Considering the Jeongseon Great syncline is the major structure that constrains the distribution of the Paleozoic strata of the Pyeongchang and Jeongseon areas, the symmetric repetition of the lower Paleozoic Joseon Supergroup in both limbs should be re-examined by structural mapping of the Hangmae and Hoedongri formations in the Pyeongchang and Jeongseon areas.