• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.5
• /
• pp.676-683
• /
• 2023

The development of the egg, larvae, and juveniles of Acheilognathus macropterus from the Wicheon stream of Nakdonggang River was investigated for early life history characteristics. The fish used in the study were collected from Wicheon stream located in Bian-myeon, Uiseong-gun, Gyeongsangbuk-do. The fertilized egg was 1.88±0.09 mm (n=30) in long diameter and 1.34±0.06 mm (n=30) in short diameter. After fertilization at a water temperature of 20℃, the egg took 31 h and 40 min to hatch. Newly hatched larvae had an average total length of 3.92±0.13 mm (n=30) and possessed a yolk sac the mouth and anus were not developed. Twenty days after hatching, the postflexion larvae had an average total length of 8.08±0.29 mm (n=30), with the tail tip fully bent at 45° and began feeding. Thirty-three days after hatching, the number of fin stems reached an integer with an average total length of 15.0±1.08 mm (n=30). In this study, differences in the egg size, hatching time, melanophore development period, and distribution location were confirmed between A. macropterus and allied species.

• Coupled systems mechanics
• /
• v.12 no.5
• /
• pp.409-418
• /
• 2023

A coupled algorithm is proposed which first considers the creation of porous structure of the material and then the simulations of response of mechanical components with porous structure to a variable load history. The simulations are carried out by the Prandtl operator approach in the finite element method (FEM) which enables structural simulations of mechanical components subjected to variable thermomechanical loads. Temperature-dependent material properties and multilinear kinematic hardening of the material can be taken into account by this approach. Several simulations are then performed for a tensile-compressive specimen made of a generic porous structure and mechanical properties of Aluminium alloy AlSi9Cu3. Variable mechanical load history has been applied to the specimens under constant temperature conditions. Comparison of the simulation results shows a considerable elastoplastic stress-strain response in the vicinity of pores whilst the surface of the gauge-length of the specimen remains in the elastic region of the material. Moreover, the distribution of the pore sizes seems more influential to the stress-strain field during the loading than their radial position in the gauge-length.

• Advances in concrete construction
• /
• v.17 no.4
• /
• pp.221-232
• /
• 2024

As a supplemental energy dissipation device, friction dampers are widely employed to augment the behaviour of buildings under seismic forces. In the current work, a methodology for the design of the friction damping system of RC frame buildings is offered using performance-based plastic design (PBPD) method. Here 2% of maximum interstorey drift ratio for life safety (LS) level is taken into account as a target drift to estimate the design base shear. In this approach, the distribution of friction damper is determined based on the hysteretic energy demand of that storey. Two frames, five storey three bay (5S3B) and eight storey three bay (8S3B) RC frame building with and without friction damping systems are also taken up for the investigation. The suggested design approach is validated by the nonlinear time history analysis (NLTHA) procedure. Inter story drift ratio (ISDR) and storey displacement, which are the more closely related to structural damage during seismic excitation are evaluated. The results show that the friction damping system on a retrofitted RC frame building performs effectively under seismic excitations and that storey displacement and ISDR are within the limit at moderate and high seismic intensities.

• Journal of Distribution Science
• /
• v.12 no.6
• /
• pp.59-65
• /
• 2014

Purpose - The competitiveness of logistics in the 21st century rests on ensuring the efficiency and effectiveness of its local hub. While considering entry into a niche market in local logistics, it is pertinent to note that Budapest is emerging as a hub in EU enlargement in Eastern Europe. Big, small, and medium-sized businesses in Korea entered Hungary in the early 1990s since then, there has been a significant increase in Korean presence, of approximately 130 times. This study aimed to identify the key distribution issues that have emerged in relation to Eastern Europe. Research design, data, and methodology - This study indicates that 33 major Korean companies were located in Hungary, which serves as an out post to enter the European marketplace. However, Korea's exports to Hungary have declined (-32.0% in 2012) because of a loss of competitiveness against multinational corporations, due to factors such as the rise in current local distribution costs and wages. Hungary, on the other hand, through diversification and expansion of foreign trade with the non-EU markets, including Korea, is increasing its exports. Strategies of emerging countries are compared and reviewed in this study, by examining the vicissitudes of Hungary's distribution methods. Results - There are issues regarding Hungary's innovative ability. Hungary has a history of low wages and high skilled labor. However, the outflow of high-quality human resources for high-wages has become more extensive, and this underlines concerns that the CEE's trade hub is moving to neighboring countries. After the European financial crisis in 2010, the Hungarian economy is now developing, because of the IMF's measures, and it is being transformed into a trade surplus nation, while regaining distribution volumes rapidly. However, if there is continued lack of investment, the supply chain is weakened and exports decline amidst competition with TNCs or with China's distribution networks. Conclusions - It is necessary to create a new logistics approach for increasing trade between Korea and Hungary. First, Korean small and medium enterprises (SMEs) should build trust by working with advanced Hungarian talent, and they should expand into state-of-the-art fields instead of being confined to traditional sectors. Second, this study focuses on limiting and lowering their high expectations for success according to foreign direct investment (FDI) inflows and the role in the CEE distribution hub Korea should try to strengthen the distribution hub with its centralized population, using better, more highly educated human resources, thereby sustaining more innovative ability. Further, the positive effects of these measures are manifested in enhanced business on both sides of Hungary, namely, the EU and non-EU nations such as Turkey and emerging markets around Europe, and a better engagement in the core placement of culture and industry. For this, Korea can contribute to, and benefit from, a Hungarian logistics center, for adopting the high-tech cluster systems and commercializing distribution technology such as RFID·USN.

• Journal of the Korean Data and Information Science Society
• /
• v.26 no.4
• /
• pp.781-790
• /
• 2015

The Parrondo paradox is the counter-intuitive phenomenon: when we combine two losing games we can win the game or when we combine two winning games we can lose the game. In this paper, we assume that an investor adopts the rule of the history-dependent Parrondo game for investment in the stock market. Using the KRX (Korea Exchange) data from 2012 to 2014, we found the Parrondo paradox in the stock trading: the redistribution of profits among accounts can turn the decrease of the expected cumulative profit into the increase of the expected cumulative profit. We also found that the opposite case, namely the reverse Parrondo effect, can happen in the stock trading.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.5
• /
• pp.1767-1770
• /
• 2012

Background: The Asia Pacific consensus for colorectal cancer (CRC) recommends that screening programs should begin by the age of 50. However, there have been reports about increasing incidence of CRC at a younger age (i.e. early-onset CRC). Little is known about the features of early-onset CRC in the Vietnamese population. Aim: To describe the clinical, endoscopic and pathological characteristics of early-onset CRC in Vietnamese. Method: A prospective, cross-sectional study was conducted at the University Medical Center from March 2009 to March 2011. All patients with definite pathological diagnosis of CRC were recruited. The early-onset CRC group were analyzed in comparison with the late-onset (i.e. ${\geq}$ 50-year-old) CRC group. Results: The rate of early-onset CRC was 28% (112/400) with a male-to-female ratio of 1.3. Some 22.3% (25/112) of the patients only experienced abdominal pain and/or change in bowel habit without alarming symptoms, 42.9% (48/112) considering their symptoms intermittent. The rate of familial history of CRC in early-onset group was significantly higher that of the late-onset group (21.4% versus 7.6%, p<0.001). The distribution of CRC lesions in rectum, distal and proximal colon were 51.8% (58/112), 26.8% (30/112) and 21.4% (24/112), respectively; which was not different from that in the late-onset group (${\chi}2$, p = 0.29). The rates for poorly differentiated tumors were also not significantly different between the two groups: 12.4% (14/112) versus 8.3% (24/288) (${\chi}2$, p = 0.25). Conclusion: A high proportion of CRC in Viet Nam appear at an earlier age than that recommended for screening by the Asia Pacific consensus. Family history was a risk factor of early-onset CRC. Diagnosis of early-onset CRC needs more attention because of the lack of alarming symptoms and their intermittent patterns as described by the patients.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.9
• /
• pp.1325-1330
• /
• 2010

The breakdown of any critical component of a turbine results in the outage of power plants. Unexpected failure decreases equipment utilization and causes enormous economic losses. Currently, we conduct conservative preventive maintenance for a maintenance period that is proposed by a vendor. In the rapidly changing business environment, reliability-based maintenance is required in order to remain competitive and reduce maintenance costs while maintaining the reliability of equipment. In order to determine an appropriate maintenance period for guaranteeing reliability, we must determine the failure probability by carefully analyzing the failure history of the equipment. In this study, we created a database of failure history for power-plant turbines, predicted the best repair time using the Weibull function, and investigated how the appropriate maintenance cycle can be determined.

• Earthquakes and Structures
• /
• v.19 no.4
• /
• pp.243-259
• /
• 2020

This study aims to optimize, design, and predict the MTMDs performance in SDOF systems using spectral analysis, and then apply their results to MDOF structures. Given the importance of spectral analysis in the design of new engineering structures, achieving a method for designing TMDs based on this theory can be of great importance for structural designers. In this study, several convenient combinations of MTMDs in an SDOF system are first considered to minimize the maximum displacement. For calculating the frequency ratios of dampers, an innovative technique is adopted in which the values of different modal responses obtained from the spectral analysis are approached together. This procedure is done using a harmony search (HS) algorithm. Also, using the random vibration theory, the damping ratio of the dampers is obtained. Then, an equation is presented for predicting the performance of MTMDs. For evaluating this equation, three structures with different stories are designed. Some of the presented combinations of dampers are added to them. The time history analyses are employed to analyze the structures under 30 different accelerograms. The findings indicated that the proposed equation could efficiently predict the performance of the MTMDs. Furthermore, four different patterns of damper distribution along the height of the structures are defined. The effect of them on the maximum deformation of the structures in time history analyses is discussed, and an equation is presented to estimate this effect. The results indicated that the average and maximum error percentages of the proposed equations are about three and seven percent, respectively, compared to the time history analyses results, which are negligible values.

• Journal of Korean Society of societal Security
• /
• v.3 no.1
• /
• pp.33-42
• /
• 2010

This study predicts the stress history for truss bridge with local damages by using global-local model combination method. For this end, the global structure is modeled by 3D frame elements and the selected local details are modeled by shell elements. Then superposition principle enable the global-local model to be combined interactively. Because the frame model cannot consider the rigidity of gusset plate and the interation of structural members due to the complexity of stress distribution in truss connection. The section modification factors are proposed to calibrate the stiffness of global frame element. The global-local model combination is verified by comparing the numerical results with experimental data obtained from the proof loading test to the operating truss bridge. Furthermore, stress histrories of the truss bridge are generated in the consideration of the rigidity of truss connection with local damage by using the combination method.

• Journal of Haehwa Medicine
• /
• v.10 no.1
• /
• pp.437-451
• /
• 2001

The clinical study was carried out the 30 patients with tremor who were treated in Daejeon University Oriental Hospital from 1 April 1997 to 31 March 2001. The results were summarized as follows. 1. The ratio of female was higher, especially in the psychosomatic tremor, the ratio of female was higher and in the age distribution the aged over 50 were higher frequence. 2. The case without past history was most, the most ordinary preceding disease was hypertention and the next was diabetes, drinking history had no concern with tremor, first visit was most, in the psychosomatic tremor complication by relation was the most inducing factor and both parkinson tremor and essential tremor were no inducing factor. 3. Tremor appeared to be busy in extremities, parkinson tremor appeared to be accompanied with musculoskeletal system symptoms and they were in descending order lower limb weakness, extremities numbness, general body weakness e.t.c. both essential tremor and psychosomatic tremor appeared to be accompanied with psychosomatic symptoms and they were in descending order dizziness, headache e.t.c. 4. In classification of Four Human coporeal constitution the number of patients, Tae-Eum-In(太陰人) was most, the prescription drugs of tranquillizing the liver and relieving anxiety such as GYEJIYONGGOLMORYETANG(桂枝加龍骨牡蠣湯) and nourishing Yin, blood and relieving anxiety such as SAMULANSINTANG(四物安神湯) were used to be busy. 5. The rate of treatment was collectively improved and was higher in the yaung age than in the old age, the period of the clinical history was the shorter within one month, the rate of improvement was the better.