• Korean Journal of Environment and Ecology
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• v.15 no.3
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• pp.257-266
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• 2001

Trail might be the primary recreational space to appear the use impact by visitors on ecological space in National park. On the basis of this concept, the carrying capacity was estimated on the trail. Impact rating class and pattern of passersby were surveyed on the 22 valid trails in Bukhansan National Park. Using two variables, the width of trail and amount of passersby, the correlation coefficient was analysed and the regression model was derived by raising x to a higher power. And carrying capacity estimation equation was devised by considering the pay fee visitors and average passersby in a trail section. With carrying capacity estimation equation to apply Bukansan National Park, it is desired that maximum carrying capacity is about 3 million persons a year under conditions of trail width 2.2m when National Park Authority wants to keep the existing management level. If they strengthen the management goal far resource conservation like that they want to keep the trail width 2.0m, the number of visitors might be decreased to about 2 million persons a year.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.83-92
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• 2023

PURPOSE: This study examined the effect of using a smartphone according to the direction of wearing a bag on muscle characteristics and balance ability in adults in their 20s with chronic ankle instability. METHODS: Twelve people with chronic ankle instability were examined for three weeks. The types of carrying a bag were classified into three conditions: to the right, to the left, and on both sides. The muscle characteristics and balance ability were measured and analyzed. The one-way ANOVA was used to obtain a difference between conditions. RESULTS: A significant difference in the muscle tone of medial gastrocnemius was observed between the dominant group and the non-dominant group. The muscle tone and stiffness of the peroneus longus decreased significantly after walking with a smartphone and carrying a bag. The maximum slope of the forward and reverse directions increased and decreased significantly, respectively, after walking with a smartphone and carrying a bag on both sides. CONCLUSION: In this study, muscle fatigue causes a decrease in muscle tone and stiffness with chronic ankle instability when carrying a heavy back while walking, and there were asymmetric changes in the balance ability. Therefore, adults with chronic ankle instability should carefully avoid carrying a heavy bag for extended times, irrespective of the style or type of the bag.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.81-88
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• 2008

The purpose of this study is to improve and modify the evaluation method of load carrying capacity for simply supported PSC I Typed girder bridge. To do this, conventional ASD(Allowable Stress Design) and USD(Ultimate Strength Design) evaluation method were initially investigated and it was evaluated that the conventional USD evaluation method may perform the load carrying capacity as conservative because it do not consider the prestressing upper-force effect of simply supported PSC I Typed girder bridge. To reasonably evaluate the load carrying capacity, the upper-force effect should be considered to the PSC I Typed girder bridge. Thus, in this study, the MUSD method was Suggested and compared to the nonlinear FEM based-load carrying capacity using the live load factor and the efficiency of the evaluation method of load carrying capacity was investigated by experimental and analytical result. In the result of this study, the suggested MUSD evaluation method showed a reasonable evaluating result for the simply supported PSC bridge. For the new technique of load carrying capacity based on the nonlinear FEM analysis, it could effectively simulate the load-deflection relationship and the load carrying capacity of the PSC I Typed girder bridge.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.1
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• pp.60-67
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• 2010

For sustainable use of the resources of uninhabited islands of Korea, their ecological economic potential needs to be fully integrated into their management policy and the carrying capacity of the islands should be evaluated before using or developing them. The emergy methodology was used to evaluate the ecological economic value and carrying capacity of Sungap-do which is an uninhabited island in Incheon, Korea. The system boundary for the emergy evaluation of the island included the sea area within 1km from the high tide level, following the management boundary for the uninhabited islands of Korea stipulated in the Law on the Conservation and Management of Uninhabited Islands. The total renewable emergy input to Sungap-do was $1.04{\times}10^{20}$ sej/yr from tidal energy. The annual ecological economic contribution of the island was evaluated high at 29.9 billion Em￦/yr. If Sungap-do were developed to the national average, its carrying capacity was 6,586 persons at the current living standard of Korea. The carrying capacity of Sungap-do for the long-term sustainability scenario was 2,337 persons at the same living standard as in the developed scenario. When only emergy contribution of the land area was considered, the carrying capacity of Sungap-do sharply decreased to 14 persons for the developed scenario and 5 persons for the long-term sustainability scenario. The carrying capacity of the uninhabited islands of Korea including Sungap-do, thus, needs to be considered from the initial stage of utilization or development projects to sustain the ecosystem benefits and their sustainable uses.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.359-360
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• 2009

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.16 no.2
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• pp.77-84
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• 1980

The nonstationary vibration of a rotor carrying two discs with a limited driving torque is studied theoretically by using the method of the perturbation theory. The influence of the asymmetry, torque, damping and phase difference in passing through a critical speed is studied in detail, considering the interaction between the driving source and the vibration system.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.439-448
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• 2018

With the aim of examining changes in plantar pressure while walking depending on the position of carrying a bag, this study measured the plantar pressure of 33 normal male and female adults using the F-scan System in four different positions to carry a bag: walking without carrying a bag; walking with carrying a bag on both shoulders; walking with carrying a bag on one shoulder; and walking with carrying a bag in one hand. Changes in the plantar pressure of the subjects obtained in this study and the asymmetry of the left and right feet were analyzed. The plantar pressure of the different areas of the feet in the four different positions to carry a bag was compared. The left foot, except its toes and metatarsus, showed a statistically significant difference among the five conditions, and the right foot, except its 4th and 5th caput metatarsalis, also showed a statistically significant difference (P>.05). Given the results of this study, this experiment to examine changes in plantar pressure does not seem to be enough to identify which position to carry a bag, except carrying a bag on both shoulders, would have the lowest negative impact on the feet. It will be necessary to conduct a follow-up study on changes in plantar pressure depending on the position of carrying a bag and methods that can effectively treat abnormal positions such as scoliosis and kyphosis using asymmetric loads.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.1-7
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• 2022

Background: In this study, we proposed that the population dynamics of non-native red-eared sliders (Trachemys scripta elegans) depends on the species' habitat extension and survivorship. We used a logistic equation with time-dependent habitat carrying capacity. In detail, the present carrying capacity depends on the red-eared slider population of the previous year. Anthropogenic activities such as the abandonment of previously captive red-eared sliders or the release due to religion customs would supply new habitats to the species. Therefore we assumed that anthropogenic spread increases the habitat carrying capacity. Based on the urbanization increase rate of 3% in Korea from 1980 to 2000, we assumed an annual spread of 3% to simulate the population dynamics of the red-eared slider. In addition, the effect on the population of an increase of natural habitats due to migration was simulated. Results: The close relationship between the distributions of non-native red-eared sliders and of urbanized areas demonstrates that urbanization plays an important role in providing new habitats for released individuals. Depending on the survivorship, the population of the red-eared slider in Korea increased 1.826 to 3.577 times between 1980 and 2000. To control population growth, it is necessary to reduce carrying capacity by reducing habitat expansion through prohibition of release into the wild ecosystem and careful managements of the wetland or artificial ponds. Changes in the habitat carrying capacity showed that the population fluctuated every other year. However, after several years, it converged to a consistent value which depended on the survivorship. Further, our results showed that if red-eared sliders expand their habitat by natural migration, their population can increase to a greater number than when they have a 99% survivorship in a fixed habitat. Conclusions: Further introductions of red-eared sliders into wetlands or artificial ponds should be prohibited and managed to prevent future spread of the species. Moreover, it is important to reduce the species' survivorship by restoring disturbed ecosystems and maintaining healthy ecosystems.

• Journal of Positioning, Navigation, and Timing
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• v.2 no.1
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• pp.19-31
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• 2013

It is well known that the accident of vehicles carrying hazardous materials incurs huge losses economically and socially. To detect and respond rapidly against the accident of a vehicle carrying hazardous materials, it is essential to estimate the relative navigation information between the forward tractor module and the backward trailer module of the vehicle reliably and accurately. In this paper, a precise relative positioning system based on GPS is designed, implemented, and evaluated as a prerequisite to design an effective relative navigation system for the vehicle carrying hazardous materials. An experiment using field-collected 10 Hz real GPS measurements showed that the designed relative positioning system achieves 22 cm accuracy within 15 epochs by float solutions. Also, it was found that cm-level integer solutions can be generated reliably after the quick convergence of float solutions.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.325-341
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• 2017

Objective: The purpose of this study is to suggest the guidelines of operation phases to minimize injuries and musculoskeletal disorders in manual material handling (MMH) tasks through literature reviews. The guidelines are presented as the preparing phase, lifting phase, carrying phase, and lowering phase. Also, we summarized the non-numerical general guidelines for MMH tasks. Background: Manual material handling is still a main cause to musculoskeletal disorders. Method: Procedures of a literature review are classified into database selection, keyword search, title review, abstract review related to literature selection, guideline review and arrangement. A total 48 papers and books were analyzed in detail by title and abstract reviews. Results: In the preparing phase, we suggested the basic conditions in MMH, preparing procedure, clothing and protective equipment, and education. In the lifting and carrying phases, we recommended maximal acceptable weight by frequency and body posture. In the lowering phase, we suggested the lowest weight and safety body postures. Finally, we recommended general guidelines and guideline items for MMH. General guidelines are presented to suggest worker selection, technical education, and work design parts. Conclusion: We suggested the guidelines on the four operation phases of MMH tasks such as preparing, lifting, carrying, and lowering phases. Application: The findings of this study can be utilized as guidelines for proactive recommendations according to workers in MMH tasks.