• International Area Studies Review
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• v.13 no.2
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• pp.298-324
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• 2009

The purpose of this paper is to examine the effect of the Korean won exchange rates on the Korean service trade balance. Empirical investigation shows that the USD/KRW and JPY/KRW exchange rates have main effects on the Korean service trade balance. Service balance credit and debit(receipts and payments) are negatively related with the USD/KRW and positively related with the JPY/KRW exchange rate. The depreciation of the USD/KRW and JPY/KRW exchange rates leads to the improvement of the service trade balance. Transportation balance is affected by the USD/KRW, JPY/KRW, and CNY/KRW exchange rates, travel balance by the USD/KRW exchange rate, and other business sevice balance by the USD/KRW and JPY/KRW exchange rates.

• Wind and Structures
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• v.35 no.2
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• pp.131-146
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• 2022

Tornadic wind flow is inherently turbulent. A turbulent wind flow is characterized by fluctuation of the velocity in the flow field with time, and it is a dynamic process that consists of eddy formation, eddy transportation, and eddy dissipation due to viscosity. Properly modeling turbulence significantly increases the accuracy of numerical simulations. The lack of a clear and detailed comparison between turbulence models used in tornadic wind flows and their effects on tornado induced pressure demonstrates a significant research gap. To bridge this research gap, in this study, two representative turbulence modeling approaches are applied in simulating real-world tornadoes to investigate how the selection of turbulence models affects the simulated tornadic wind flow and the induced pressure on structural surface. To be specific, LES with Smagorinsky-Lilly Subgrid and k-ω are chosen to simulate the 3D full-scale tornado and the tornado-structure interaction with a building present in the computational domain. To investigate the influence of turbulence modeling, comparisons are made of velocity field and pressure field of the simulated wind field and of the pressure distribution on building surface between the cases with different turbulence modeling.

• Wind and Structures
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• v.37 no.5
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• pp.375-382
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• 2023

The aerodynamic characteristics of a circular cylinder with a wavy splitter plate were experimentally studied, specifically the potential reduction of drag and fluctuations in drag. To study the individual effects of amplitude and wavelength, the experiments were conducted by varying one parameter at a time while holding the other one constant. To study the effect of amplitude (A), the wavelength to diameter ratio (λ/D) was fixed at 0.115 and the amplitude to diameter ratio (A/D) was varied as 0.005, 0.010, 0.015 and 0.020. Similarly, to study the effect of wavelength, A/D was fixed as 0.020 and λ/D was varied as 0.46, 0.23, 0.15 and 0.12. Analysis of the data indicated that the wavy splitter plate caused a significant reduction in both the magnitude and the fluctuation of drag. The variation of aerodynamic forces and the fluctuations with them corresponding to different Reynolds numbers were computed and the spectral aspects of fluctuating forces due to vortex shedding is analysed and effective reduction in both shedding frequency and magnitude was observed.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.3
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• pp.377-386
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• 2014

This study analyzed how alternative investment goods would affect a market in a neighboring shopping area in order to provide parties involved in the investment market of this neighboring shopping area with standards which would help them when they try to make a reasonable determination. The study estimated forms and explanation power of the effects of a bid rate of a neighboring shopping area, and came up with those results as follows. Increases in the representative macro economic indicators, the composite stock price index and the fluctuation rate of land price, including the real estate business would have a positive influence on the market of the neighboring shopping area as playing a circumstantial evidence of market recovery and yet, the increase in interest rate, the alternative investment goods, would reduce the relative price-earnings ratio which would, eventually, negatively affect the charm of the investment in the market of the neighboring shopping area. The study, now, understands that housing with a feature of consumers' goods and neighboring shopping area with a feature of investment goods would not have great concern with each other as they are observed to be two different markets from an aspect of interactionism.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.4
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• pp.318-327
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• 2012

The operating sound radiated from a laser printer includes tonal noise components caused by the rotating mechanical parts such as gear, shaft, motor, fan, etc. The negative effects of the tonal noise components need to be considered in the process of developing a sound quality index for the quantitative evaluation of the emotional satisfaction in terms of psycho-acoustics. However, in a previous paper, it was confirmed that the Aures tonality did not have enough correlation with the results of jury evaluation. The sound quality index based on loudness, articulation index, fluctuation strength has a little problem in considering the effects of rotating mechanical parts on the sound quality. In this paper, to solve the tonality evaluation problem, the calculation algorithm of Aures tonality was investigated in detail to find the cause of decreasing the correlation. The new tonality evaluation model was proposed by modifying and optimizing the masking effect, loudness ratio, and shape of weighting curve based on the basic algorithm of Aures tonality, and applied to two kinds of operating sound groups in order to verify the usefulness of proposed model. As a result, it is confirmed that the proposed tonality evaluation model has enough correlation and usefulness for expressing the tonalness in the operating sounds of laser printers. In the following paper, this results will be used to model the sound quality index as the input data by using the classification algorithm.

• Ocean and Polar Research
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• v.29 no.3
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• pp.205-216
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• 2007

The purpose of this study was to investigate effects of large scale marine sand mining on the marine ecological community. For the study, four stations along the coast were selected and monitored in 1998 and 2001 at mining areas and non-mining areas about the Gyeonggi Bay. The result revealed that in 1998, 9 species of fishes, 16 species of crustaceans, and 6 species of mollusks were collected where as in 2001, 11 species of fishes, 5 species of crustaceans, and 2 species of mollusks were collected, uncovering the fact that fishes have diversified while crustaceans and mollusks have reduced on a grand scale. Also, there were two key characteristics regarding the changes of biological communities in mining and nonmining areas. The first was the dwindling of crustaceans inhabiting the sand area. This outcome may be accounted for by the facts that physical removal of seabed sediments and re-sediment due to expansion of floating particles cause direct influence on the ocean floor ecosystem and have continuous effect on the communities of crustaceans which feed on them. Secondly, the newly arrived species and their population during spring and summer seasons have increased in the non-mining areas and have decreased in the mining area. It can be concluded that highly nomadic fish species migrate toward areas with less disturbance or destruction of ecosystem from marine sand mining, and consequently, the communities of fishes change in the sea area. Setting aside the characteristics of the investigated sea areas where the arriving conditions of species vary by seasons, the clear differences of population of organisms in those areas are due to environmental alterations owing to the marine sand mining ; if those large-scale marine sand mining activities continue in the Gyeonggi Bay, their effects on biological communities in the areas will only grow.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.859-864
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• 2014

This experimental study investigates the effects of a downstream cylinder in the wake change on upstream object's diameter. A V-shaped object is placed in the upstream of the test section and a circular cylinder containing a load-cell is placed in the downstream. The velocity distribution of the wake generated from the upstream object with a change in its diameter is investigated. Further, the fluctuation in the lift coefficient and Karman-vortex emission frequency with a change in the position of the downstream cylinder is examined. The study results reveal the following. i) The flow velocity in the wake is smaller than that in the main stream. ii) The lock-in phenomenon occurs when the diameter of the upstream object is larger than that of the downstream cylinder. iii) To generate maximum fluctuating lift force of the downstream cylinder in the wake, the position of the downstream cylinder must be moved with changing diameter of the upstream object together.

• Journal of Preventive Medicine and Public Health
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• v.36 no.1
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• pp.85-91
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• 2003

Objectives : We investigated the effects of the economic growth and unemployment rates on the suicide rate in Korea, between 1983 and 2000, using a time-series regression model. The purpose of this study was to model and test the magnitude of the rate of suicide, with the Korean unemployment rate and GDP. Methods : Using suicide rate per 100,000 Koreans and the unemployment rates between 1983 and 2000, as published by the Korea National Statistical Office, and the rate of fluctuation of the Korean GDP (Gross Domestic Product), as provided by the Bank of Korea, as an index of the economic growth rate, a time-series regression analysis, with a first-order autoregressive regression model, was peformed. Results : An 81.5% of the variability in the suicide rate was explained by GDP, and 82.6% Of that was explained by the unemployment rate. It was also observed that the GDP negatively correlated with the suicide rate, while the unemployment and suicide rates were positively correlated. For subjects aged over 20, both the GDP and unemployment rate were found to be a significant factors in explaining suicide rates, with coefficients of determination of 86.5 and 87.9%, respectively. For subjects aged under 20, however, only the GDP was found to be a significant factor in explaning suicide rates (the coefficient of determination is 38.4%). Conclusion : It was found that the suicide rate was closely related to the National's economic status of Korea, which is similar to the results found in studies in other countries. We expected, therefore, that this study could be used as the basis for further suicide-related studies.

• Journal of fish pathology
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• v.16 no.3
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• pp.183-191
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• 2003

The effect of each dietary supplements (Undaria 5%, Undaria 10%, Obosan 0.5%, Wasabi leaf 2%, Wasabi stem 2%) on the water temperature fluctuation in juvenile olive flounder (Paralichthys olivaceus) was investigated. The response to stress was assessed in terms of effects on haematological and immunological, and resistance against Edwardsiella tarda infection. Plasma glucose and cortisol levels were significantly lower in 5% undaria and 2% wasabi leaf supplement groups than the controls after the first change of water temperature (P<0.05). The plasma lysozyme activities and the survival rates from E. tarda infection were significantly higher in the 5% undaria supplement groups than the control (P<0.05). These results suggest that the 5% undaria supplement seems to be contributable to the increased disease resistance on olive flounder.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.23
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• pp.71-91
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• 2004

The purpose of this paper is to examine the effects and problems of acceptance with modifications according to CISG Art. 19, comparing with UCC ${\S}2-207$. First of all this author raised two legal issues encountered when there is an acceptance with modifications. Scenario one is as follows : "Before either party has taken further action, there is a rise or a fall in the price of goods, was there a binding contract ?" The UCC rules provide for a contract if a purchaser sends out a purchase order and the seller sends back a sales acknowledgement form, and the items on the front(the price, description, and quantity) match up. The CISG on the other hand, is that most of the terms and conditions on the backs of the forms are important. Therefore, if they are different, there should not be a contract. Scenario two is as follows : "There has been performance, A disputes arises. What terms and conditions apply ?" The CISG and the UCC will probably lead to different results in the event the parties exchange conflicting forms and subsequently perform. Assuming that the offeree's reply contains terms that are materially different from the offer, the UCC provides that the resulting contract will include only those terms on which the writings of the parties agree, excluding conflicting terms. The CISG treats the material additions as a counter-offer and, in accordance with Art. 18, the offeree's performance may be regarded as an acceptance of a contract containing all of the offeror's terms ; or the offeror's performance may be regarded as an acceptance of a contract containing all of the offeree's terms. Second, this author raised three problems in the Art. 19 as follows ; 1) It is very difficult in practical application to decide what is material alterations even if the CISG lists material terms as an example. 2) There is a possibility for the offeror to speculate in the circumstance of market fluctuation as he has a change to object to the discrepancy in the offeree's reply. 3) There is also a possibility of inducement for the offeror or the offeree to send its own reply as a last shot.