• Title/Summary/Keyword: Impact pressure

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Impact of Largemouth Bass (Micropterus salmoides) on the Population of Korean Native Fish, Crucian Carp (Carassius auratus) (배스가 국내 호소에 서식하는 붕어 개체군에 미치는 영향)

  • Lee, Jin-Woong;Kim, Jeong-Hui;Park, Sang-Hyeon;Choi, Kee-Ryong;Lee, Hae-Jin;Yoon, Ju-Duk;Jang, Min-Ho
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.370-375
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    • 2013
  • Exotic species in aquatic ecosystem generate various problems domestically as well as globally. Largemouth bass (Micropterus salmoides) which is a well-known exotic species globally, acts as a substantial disturbance factor on the native fish communities in Korea due to the high predation pressure and hence designated as a ecologically harmful species by Ministry of Environment. In this study, we investigated the impact of largemouth bass on Korean native fish population, crucian carp (Carassius auratus), to identify responses of the prey fish. Two fish species were collected at seven reservoirs distributed at the Nakdong River catchment area, and changes in length-frequency and length-weight relationship (LWR) were analysed depending on existence of large-mouth bass. At bass absent sites, ratio of under age 1 year individuals were small, and over age two years were dominant. Conversely, normal length-frequency distribution pattern was identified at bass absent sites. The LWR of crucian carp (fish smaller than total length of 160 mm were only considered as it is frequently consumed by bass predation) was different depending upon bass existence. The value of parameter b at bass absent reservoirs was 2.909, which was smaller than that of bass present reservoirs, 3.100. Our results imply that crucian carp at bass present reservoirs presented a different strategy to survive from predation by bass, through relatively rapid growth. We propose that other native species might have similar growth strategies like crucian carp.

Factors Affecting Hemodynamic Instability in Patients with Pelvic Bone Fracture (골반골 골절 환자의 혈역학적 불안정화에 미치는 영향요소)

  • Park, Seung Min;Lee, Kang Hyun;Choi, Han Ju;Park, Kyung Hye;Kim, Sang Chul;Kim, Hyun;Hwang, Sung Oh
    • Journal of Trauma and Injury
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    • v.21 no.1
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    • pp.22-27
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    • 2008
  • Purpose: Treatment and prognosis in patients with pelvic bone fracture depend on the characteristics of the fracture and the stability of the pelvic ring. The purpose of this study is to analyze the characteristics of and the relationships between fracture patterns, injury mechanisms, clinical courses, and prognoses according to the hemodynamic pattern. Methods: Between January 2004 and September 2006, 89 patients under diagnosis of pelvic bone fracture were retrospectively analyzed on the basis of medical records and radiologic examinations. Patients with confirmed hemorragic shock with a systolic pressure of less than 90 mmHg were defined as the shock group. Young's classification was used to characterize fracture patterns. Factors relating to the clinical manifestation and to treatments such as transfusion and surgery were analytically compared. Results: The mean age of the patients was $48.8{\pm}18.7$, among which 49 (55.1%) were male. The numbers of shock and non-shock patients were 35 (39.3%) and 54 (60.7%) respectively. Eighteen (51.4%) of the shock patient had injuries resulting from pedestrian accidents (p=0.008). According to Young's classification, lateral impact fractures amounted to 20 and 33, front-rear impact fractures to 9 and 20, and multiple fractures to 6 and 1 among the shock and non-shock patients, respectively (p=0.027). Thirty-nine (39) cases in non-shock injuries were conservatively managed while 18 cases in shock injuries were surgically treated. In the shock group, the liver and the kidney were often damaged, as well. Among the shock patients, the average admission period was $7.5{\pm}8.7days$ in intensive care and $55.1{\pm}47.9days$ in total, which were longer than the corresponding numbers of days for the non-shock patients (p<0.05). No deaths occurred in the non-shock group while 5 deaths (14.2%) occurred in the shock group (p=0.007). Conclusion: The factors affecting hemodynamic instability in patients with pelvic bone fracture are injury mechanism, classification of fracture, and associated injuries.

Impact of interhospital transfer on outcomes for trauma patients: impact of direct versus non-direct transfer (비외상센터에서 외상센터로의 전원이 예후에 미치는 영향)

  • Yang, Wook Tae;Min, Mun Ki;Ryu, Ji Ho;Lee, Daesup;Lee, Kang Ho;Shin, Jin Wook;Yeom, Seok Ran;Han, Sang Kyun
    • Journal of The Korean Society of Emergency Medicine
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    • v.29 no.5
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    • pp.415-422
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    • 2018
  • Objective: This study compared the prognosis of patients who visited the trauma center directly (direct visit group) with those transferred from the non-trauma center (transferred group). Methods: The patients, who were 18 or older with Injury Severity Score of 15 or more in the trauma center at Busan, were studied from October 2015 to October 2016. To compare the treatment time between the direct visit and transferred group, first treatment time, final treatment time, and time to visit the trauma center were examined. To compare the prognosis, this study compared the 48-hour, 7-day, and in-hospital mortality rate as well as the duration of intensive care unit (ICU) and total hospital stay. To analyze the factors affecting the outcome of transferred group, the physician's level and procedures that had been performed at the non-trauma center were examined. Results: The mortality was similar in the direct visit and transferred group (48-hour 7.6% vs. 4.6%, P=0.111; 7-day 11.1% vs. 7.2%, P=0.89; and in-hospital 14.6% vs. 11.3%, P=0.214). The length of ICU and total hospital stay were similar in the two groups. The mortality was higher in the patients in the transferred group when using intubation, transfusion, and pressure intensifier. The intubated patients showed higher mortality according to logistic regression. Conclusion: The mortality, length of ICU, and hospital stay were similar but the time to visit the trauma center and the final treatment time were longer in transferred group. Stabilizing the patient at the near non-trauma center may be more helpful for some patients.

Research on the Urban Green Space Connection Paths forthe Enhancement of Ecological Function - Focused on Suwon - (녹지축의 생태적 기능 강화를 위한 도시녹지 연결경로 도출 연구 - 수원시 대상 -)

  • Choi, Jaeyeon;Kim, Suryeon;Park, Chan;Song, Wonkyong;Jung, Kyungmin;Kim, Eunyoung
    • Journal of Environmental Impact Assessment
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    • v.31 no.4
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    • pp.201-213
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    • 2022
  • Creation and administration of green space are emphasized to solve the environmental problem and the management of green space in urban area. Urban area with high development pressure faces green space fragmentation, so the planned approach is needed to improve the continuity of green space. However, the current institutional green axis, used to enhance continuity of urban space is merely an abstract concept under the master plan so that is not a consistent framework for urban green continuity providing no detailed information such as position and path. Therefore, in order to consistently manage green space in continuous point of view, it is insufficient not being connected to each individual green space development projects. This study proposes a method for finding the connection path to enhance urban green space continuity. This proposed method consists of two phases. First phase is finding nodes to connect current green space and second is to calculate the least cost path. We calculate connection cost using NDMI (Normalized Difference Moisture Index), impervious ratio and official land cost, applying to Suwon city and potential greening site that was planned in official master plan. According to the results, we confirm a possibility of finding a cost-effective connection path with detailed spatial information instead of unrealistic abstract concepts and discuss worth applying to a legally plan and policy.

Applying the TDR for Urban Landscape Management: Focusing on the Use of REITs (도시 경관관리를 위한 개발권양도제 정책도입에 관한 연구: 리츠 접목을 중심으로)

  • Dongoh Ha;Jaeweon Yeom;Juchul Jung
    • Journal of Environmental Impact Assessment
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    • v.32 no.4
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    • pp.242-250
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    • 2023
  • The continuity of urban space is being destroyed by disorderly high-rise development caused by reckless development, and the resulting deterioration of urban landscape is emerging as a major problem. Disordered high-rise development is adversely affecting the urban environment, such as depriving residents of the basic rights of view and sunlight and privatizing the scenery that urban residents should enjoy together. In order to create a continuous urban landscape, indiscriminate high-rise development is restricted and compensation for the affected areas is needed. Various regulations have been carried out to this end, but it is difficult to overcome the pressure and damage to high-rise development by regulations alone. Accordingly, discussions have been underway to introduce a compensation system. Among them, discussions on the introduction of a 'Transfer of Development Right' (TDR) in which land ownership and development rights are separated and compensated for development rights have been drawing attention. However, in Korea, it is difficult to introduce the system due to various problems related to the separation of development rights. In order to overcome the limitations of the introduction of TDR, this paper analyzed the concepts and characteristics of 'Real Estate Investment Trusts' (REITs) and presented a policy model for the development right transfer system incorporating REITs for effective landscape management.

Performance Evaluation for All-In-One Construction Method of Curbstone and Gutter Using Formwork Rail and Jig (거푸집 레일과 지그를 이용한 경계석 및 측구의 일체형 시공법에 대한 성능평가)

  • Choi, Jae-Jin;Ko, Man-Gi;Kim, Kyoung-Ju;Choi, Khyung-Dong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6A
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    • pp.525-534
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    • 2010
  • A road curbstone is a structure installed at the boundary of the sidewalk and the street with the objectives of road drainage, drawing attention and such. The current general construction method of curbstones places foundation concrete for the curbstones first, waits until the concrete reaches the strength to support the curbstones, places the curbstones on top, and then places the gutter and rear filling concrete. Such method has the issues of poor compaction and weakened bond strength of concrete due to split placing of concrete, and causes the curbstones to easily separate due to vehicle impact or earth pressure, in turn creating maintenance costs and spoiling the aesthetics. To improve such conventional construction methods, an all-in-one method was developed using formwork rail and jig where both the curbstones and gutter can be worked at the same time, and to evaluate the structural performance, static tests of lateral loading test, pullout test, and bending test were executed, and dynamic tests such as pendulum test and actual vehicle impact test were executed. In all tests, the all-in-one construction method using formwork rail and jig was shown to be superior to the conventional construction method by the increase of construction quality and bond strength of concrete.

Effect of Supply Chain Risk on Port Container Throughput: Focusing on the Case of Busan Port (공급망 리스크가 항만 컨테이너 물동량에 미치는 영향에 관한 연구: 부산항 사례를 중심으로)

  • Kim, Sung-Ki;Kim, Chan-Ho
    • Journal of Korea Port Economic Association
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    • v.39 no.2
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    • pp.25-39
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    • 2023
  • As the scope of supply chains expands globally, unpredictable risks continue to arise. The occurrence of these supply chain risks affects port cargo throughput and hinders port operation. In order to examine the impact of global supply chain risks on port container throughput, this study conducted an empirical analysis on the impact of variables such as the Global Supply Chain Pressure Index (GSCPI), Shanghai Container Freight Index (SCFI), Industrial Production Index, and Retail Sales Index on port traffic using the vector autoregressive(VAR) model. As a result of the analysis, the rise in GSCPI causes a short-term decrease in the throughput of Busan Port, but after a certain point, it acts as a factor increasing the throughput and affects it in the form of a wave. In addition, the industrial production index and the retail sales index were found to have no statistically significant effect on the throughput of Busan Port. In the case of SCFI, the effect was almost similar to that of GSCPI. The results of this study reveal how risks affect port cargo throughput in a situation where supply chain risks are gradually increasing, providing many implications for establishing port operation policies for future supply chain risks.

Study on the Free Roll Decay and Resistance Performances of Fishing Vessels by Varying Appendages (어선 부가물 별 자유 횡 동요 감쇠 및 저항성능에 관한 연구)

  • Mijin Yoon;Janghoon Seo;Dong-Woo Park;Chanjae Lee;Intae Kim;Dong Nam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.6
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    • pp.688-696
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    • 2023
  • In the present study, free roll decay and resistance performances of fishing vessels were evaluated with the combinations and variations of in the parameters of appendages which are attached to improve motion performance of fishing vessels. Computational Ffluid Ddynamics was used to perform free roll decay and resistance analysis. The roll period and decay coefficient were derived by the variations in the combination and dimensions of the primary appendages of the bilge keel and the under keel. It was observed thatThe variations of in the length of the under keel did not significantly impact to the roll damping coefficient. Conversely, for the bilge keel, an increase in the length and angle resulted in an increase in the roll damping coefficient. Comparison of resistance performance was additionally assessed among the selected hulls with the appendages and bare hull. The resistance of the hull with the appendages was higher than that of the bare hull due owing to the changes of in the pressure on the surface of the hull and trim angle. Throughout the present study, the impact of appendage parameter and arrangement on the free roll decay and resistance performance of fishing vessels were was assessed,. which This will be beneficial for the application of appendages to fishing vessels.

Korean society and educational achievement (V): The contribution of educational achievement for the future of Korean society (한국 사회와 교육적 성취 (V): 교육적 성취를 통한 미래 한국 사회의 모색)

  • Youngshin Park;Uichol Kim
    • Korean Journal of Culture and Social Issue
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    • v.14 no.1_spc
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    • pp.427-468
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    • 2008
  • This article examines the role and influence of educational achievement on Korean society and its future. Four major factors that associated with and influence educational achievement in Korea (i.e., trust, efficacy beliefs, quality of life, and societal transformation) are reviewed. First, the role of educational achievement on establishing a basis for trust in Korean society is examined. By reviewing studies of perception of Korean society, people and institutions, the importance of establishing trust in Korean society is outlined. Second, the role of efficacy belief in promoting educational achievement is examined. The importance of collective efficacy, at the adolescent, adult and political levels is emphasized. In addition, the concept and application of self-efficacy for teachers and parents is reviewed. Third, the role and influence of educational achievement on quality of life is outlined. Studies indicate that educational achievement plays an important role in improving the quality of life. The pressure to achieve, however, can have negative impact on stress and mental health and support systems need to be developed to alleviate their impact. Fourth, the future and prospects for Korean society through educational achievement is discussed. Through education, the importance of bridging the divide with North Korea is an important agenda for the future of Korean society. Finally, the importance of indigenous psychological perspective in understanding Korean society and providing direction for the future is discussed.

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Seismic Impact Analysis of Buried Citygas Pipes through Structural Analysis (구조해석을 통한 도시가스 매설배관의 지진 영향 분석)

  • Yoon Ho Jo;Maria Choi;Ju An Yang;Sang Il Jeon;Ji Hoon Jeon
    • Journal of the Korean Institute of Gas
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    • v.27 no.4
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    • pp.19-26
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    • 2023
  • Earthquakes are one of the most important disasters affecting underground structures. Urban gas underground pipes may cause safety problems of structures in the event of an earthquake. Since Korea began digital observation, the number of earthquakes has been steadily increasing. The seismic design standard for urban gas pipes was established in 2008, but it is difficult to estimate the impact of pipes in the event of an earthquake based on the installation of pipes. In this study, structural analysis was performed on PE (polyethylene pipe) pipes and PLP (polyethylene coated steel pipe) pipes, which are mainly used as buried pipes in Korea, according to environmental and pipe variables in the event of an earthquake. This study sought to find the variables of the most vulnerable buried pipe by modeling pipes through Computer Aided Engineering (CAE) and generating displacement on the ground. Through this study, it was confirmed that the larger the elastic modulus of the soil, the deeper the buried depth, the smaller the tube diameter, and the higher the pressure, the more PLP pipes are affected by earthquakes than PE. Based on these results, the vulnerable points of buried urban gas pipes are inferred and used for special inspections of buried pipes in the event of an earthquake.