• Title/Summary/Keyword: ports

Search Result 1,858, Processing Time 0.026 seconds

Review of the Improvement of the Estimation Method of Harbor Tranquility (항만정온도 추정방법 개선방안 검토)

  • Jeong, Weon Mu;Ryu, Kyong-Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.26 no.6
    • /
    • pp.397-404
    • /
    • 2014
  • In Korea, harbor tranquility is generally estimated by using both methods of investigating harbor calmness under abnormal wave condition and evaluating the harbor serviceability. The efficiency of the former method is questionable as the tranquility of a harbor is judged by a wave height criterion that is arbitrarily determined without rational basis. In case of the latter method, the utilization rate of a harbor is estimated by using the exceedance probability of wave height or the distribution of wave heights and periods that is obtained from longterm measured or hindcasted wave data. Use of long-term data is desirable in order to guarantee the accuracy of the exceedance probability. Meanwhile, the criterion for determining maximum allowable wave height for cargo handling works is too simple and has limitations for being used in an actual field condition. Problems of existing method for estimating harbor tranquility were verified by the wave observation data in Busan New Port. And the importance of the field observation data was emphasized. It is necessary to perform long-term wave monitoring inside and outside of major ports in Korea in order to establish more advanced standard for evaluating harbor tranquility based on such observed wave data.

Simulation of Solitary Wave-Induced Dynamic Responses of Soil Foundation Around Vertical Revetment (고립파 작용하 직립호안 주변에서 지반의 동적응답에 관한 수치시뮬레이션)

  • Lee, Kwang-Ho;Yuk, Seung-Min;Kim, Do-Sam;Kim, Tae-Hyeong;Lee, Yoon-Doo
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.26 no.6
    • /
    • pp.367-380
    • /
    • 2014
  • Tsunami take away life, wash houses away and bring devastation to social infrastructures such as breakwaters, bridges and ports. The targeted coastal structure object in this study can be damaged mainly by the tsunami force together with foundation ground failure due to scouring and liquefaction. The increase of excess pore water pressure composed of oscillatory and residual components may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, the solitary wave was generated using 2D-NIT(Two-Dimensional Numerical Irregular wave Tank) model, and the dynamic wave pressure acting on the seabed and the estimated surface boundary of the vertical revetment. Simulation results were used as an input data in a finite element computer program(FLIP) for elasto-plastic seabed response. The time and spatial variations in excess pore water pressure, effective stress, seabed deformation, structure displacement and liquefaction potential in the seabed were estimated. From the results of the analysis, the stability of the vertical revetment was evaluated.

Antioxidant Effects of Sesamin and Sesamolin in Streptozotocin-induced Diabetes Mellitus Rat (Streptozotocin유발 당뇨쥐에서 세사민과 세사몰린의 항산화효과)

  • 성하정;강명화;정혜경;송은승;정미혜
    • Journal of Food Hygiene and Safety
    • /
    • v.16 no.4
    • /
    • pp.349-354
    • /
    • 2001
  • Oxidative stress is believed to play an important role in the development of vascular complications associated with diabetes mellitus. We examined the antioxidative effect of sesamin and sesamolin on the preventing the development of insulin dependent diabetes mellitus using streptozotocin-induced Spraque Dawley diabetic rats. From 48 hours after injection of streptozotocin (60 mg/kg body weight), a portion of diabetic rats were fed with 0.2% sesamin and sesamolin containing diet for 3 weeks. There were significant differences of blood glucose and kidney weight between diabetic ports and control. Sesamin and sesamolin increased glutathione-S-transferase activity in kidney. The concentration of the thiobarbituric acid-reactive substances in the serum, liver, and kidney of diabetic rats administered sesamin and sesamolin decreased significantly as compared with that of the non-treated diabetic group. Dietary sesamin and sesamolin suppressed the oxidative stress in the diabetic rats. These results demonstrated that sesamin and sesamolin are potential and effective antioxidants that can protect the complications associated with diabetes.

  • PDF

A Study on Improving Measures against Terrorism in Metropolitan Subways (지하철내 테러대응 개선방안의 연구)

  • Park, Woong-Shin
    • Korean Security Journal
    • /
    • no.50
    • /
    • pp.91-115
    • /
    • 2017
  • Recently the characteristics of those who committed serious terrorist crimes are not directly related to the direct command system of a specific terrorist organization (ex. IS) but are influenced by the political propaganda of terrorist organizations online, Terrorist crime under the loose form of the terrorist organization. Therefore, this study suggests ways to improve countermeasures against terrorism in metropolitan subways. Although it is important for the prevention of terrorism in the subway, it is important for the police officers of the subway police and the special police officers of the railway to have a physical limit to take charge of them, and after confirming that improvement measures are necessary, And pointed out the possibility of establishing independent security departments where judicial and administrative control is not feasible to grant police rights. In addition, I pointed out how to improve the safety of subways in the metropolitan area through the recruitment of core job candidates and the identity survey during the subway operation. Furthermore, it was confirmed that a special council on terrorism, which can take into consideration the characteristics of subway terrorism, such as airports and ports, is required to be established in charge of terrorism prevention under the current Anti-Terrorism Act. Finally, it is once again emphasized that the strengthening of the powers of the counterparts to terrorism must inevitably limit the basic rights of the people, so the principle of proportionality must be observed in their activities.

  • PDF

Single Incision Flexible Endoscopic Cholecystectomy in Dogs : Feasibility Study (개에서 단일 통로 유연 내시경 담낭 절제술 : 유용성 연구)

  • Lee, So-Yeon;Shin, Beom-Jun;Jeong, Seong-Mok
    • Journal of Veterinary Clinics
    • /
    • v.28 no.6
    • /
    • pp.555-561
    • /
    • 2011
  • Laparoscopic surgery is a well-established alternative to open surgery across disciplines. However, in veterinary medicine, laparoscopic surgery in dogs was rarely reported because of small abdominal size for multiple ports insertion. The concept of single-incision laparoscopic surgery (SILS) is to perform the entire laparoscopic operation through a single incision rather than conventional multiple small skin incisions. Indirect evidence of potential benefits of SILS, decreases operative morbidity related to reduction in port size, already exists. Therefore, this study was performed to evaluate the safety and feasibility of the modified form of SILS using flexible endoscope in Cholecystectomy before clinical adoption. A 2 cm single periumbilical incision was performed, and flexible endoscope was introduced into the abdominal cavity. A laparoscopic grasper was inserted into the abdominal cavity for the traction of gall bladder. Cystic duct and artery were ligated by 5 mm Hem-o-lok$^{(R)}$. Then, gall bladder was dissected and resected from the liver with 5 mm Autonomy Laparo-Angle Maryland dissector and endoscopic needle knife. Resected gall bladder was wrapped by using specimen pouch and was retrieved through abdominal incision from the cavity. All three gall bladders were successfully removed. Hematological changes were not observed during examination periods. No leakage sign was identified at necropsy. The flexible endoscope, as distinct from conventional rigid laparoscope, allows the visualization from various angles and the wide range of motion, result in less crowding.

Study on Creation Method of Green Space for Port Ecosystem Using the Halophytes (염생식물을 이용한 항만 녹색공간 창출기법에 관한 연구)

  • Myeong, Hyeon-Ho;Lee, Jeom-Sook;Jeon, Ji-Young;Song, Man-Soon
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.23 no.1
    • /
    • pp.50-56
    • /
    • 2011
  • To make conservative port and coast ecosystems and creative the greenspace, We were investigated with characteristic of flora, environmental factors, types of port, adaptive species, minimum conservation area and plantation model. In 50 sites of study areas, there are 19 families and 174 species of vascular plants and 19 families and 48 species of halophytes. Dominant communities in port ecosystem contains Carex kobomugi community, Elymus mollis community, Carex pumila community, Ixeris repens community, Vitex rutundifolia community, Calystegia soldandlla community, Rosa rugosa community, Lathyrus japonica community, Salsola komarovi community, Cynodon dactylon community, Tetragonia tetragonioides community, Suaeda japonica community, Suaeda maritima community, Zoysia sinica community and Phragmites communis community. We carried out Canonical Correspondence Analysis(CCA) for ordinations on the vegetation and plant communities-environmental variable matrices in 50 sites. The communities tended to cluster into three types: Clay marsh, Sand marsh, Sand gravel marsh types. Adaptive species in habitate types are selected that sand marsh-type communities in ports contained Elymus mollis community, Ixeris repens community, Carex kobomugi community, Carex pumila community, Clay marsh-type communities contained Suaeda japonica community, Phragmites communis community, Zoysia sinica community and Suaeda maritima community, Sand gravel marsh-type communities contained Vitex rutundifolia community, Calystegia soldandlla community. We are conducted the estimation of minimal area for plantation of adaptive plant species and carried out guide line and plantation model for creation of green space in port ecosystem.

Construction Methods of Switching Network for a Small and a Large Capacity AMT Switching System (소용량 및 대용량의 ATM시스템에 적합한 스위칭 망의 구성 방안)

  • Yang, Chung-Ryeol;Kim, Jin-Tae
    • The Transactions of the Korea Information Processing Society
    • /
    • v.3 no.4
    • /
    • pp.947-960
    • /
    • 1996
  • The primary goal for developing high performance ATM switching systems is to minimized the probability of cell loss, cell delay and deterioration of throughput. ATM switching element that is the most suitable for this purpose is the shared buffer memory switch executed by common random access memory and control logic. Since it is difficult to manufacture VLIS(Very Large Scale Integrated circuit) as the number of input ports increased, the used of switching module method the realizes 32$\times$32, 150 Mb/s switch utilizing 8$\times$8, 600Mb/s os 16$\times$16, 150Mb/s unit switch is latest ATM switching technology for small and large scale. In this paper, buffer capacity satisfying total-memory-reduction effect by buffer sharing in a shared buffer memory switch are analytically evalu ated and simulated by computer with cell loss level at traffic conditions, and also features of switching network utilizing the switching module methods in small and large-capacity ATM switching system is analized. Based on this results, the structure in outline of 32$\times$32(4.9Gb/s throughput), 150Mb/s switches under research in many countries is proposed, and eventually, switching-network structure for ATM switching system of small and large and capacity satisfying with above primary goals is suggested.

  • PDF

Port's Successful Global Supply Chain Strategies - Focusing on the case of Dubai port - (항만의 성공적인 글로벌 공급사슬 전략 - 두바이항의 사례를 중심으로 -)

  • Han, Chul-Hwan
    • Journal of Korea Port Economic Association
    • /
    • v.24 no.2
    • /
    • pp.175-192
    • /
    • 2008
  • Today's individual firms no longer compete as solely autonomous entities, but rather as supply chain. As such the competitive position of a port is not only determined by its internal strengths but also it is also affected by its links in a global supply chin. In other words, port competitiveness is becoming increasingly dependent on external coordination and control of the whole supply chain. The main purpose of this paper is to examine how a port embeds itself into supply chain in order to strengthen its competitive position by focusing on Dubai port case. This paper found that Dubai port used three phases-insertion, integration and dominance-as a strategies for how it can embedded into global supply chain successfully. Dubai's global supply chain strategies give some implications for the further development of the Port of Gwangyang. First, the Port of Gwangyang should fully utilize symbiotic relationship with Gwangyang free Economic Zone. Second, the integration between Korea Container Terminal Authority and GYFEZ can be recommended for fast decision-making and providing a one-stop-service. Finally, Gwangyang should pursue an aggressive supply chain strategy, aims at dominance in the regional port network through port alliance with small and medium ports in neighboring area.

  • PDF

Evaluation of dynamic ground properties using laterally impacted cross-hole seismic test (횡방향 발진 크로스홀 탄성파 시험을 이용한 지반의 동적 특성 평가)

  • Mok Young-Jin;Sun Chang Guk;Kim Jung-Han;Jung Jin-Hun;Park Chul-Soo
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2005.09a
    • /
    • pp.155-175
    • /
    • 2005
  • Soil and rock dynamic properties such as shear wave velocity (VS), compressional wave velocity (VP) and corresponding Poisson's ratio ( v ) are very important geotechnical parameters in predicting deformational behavior of structures as well as practicing seismic design and performance evaluation. In an effort to measure the parameter efficiently and accurately, various bore-hole seismic testing techniques have been, thus, developed and used during past several decades. In this study, cross-hole seismic testing technique which is known as the most reliable seismic method was adopted for obtaining geotechnical dynamic properties. To perform successfully the cross-hole test for rock as well as soil layers regardless of the ground water level, spring-loaded source which impact laterally a subsurface ground in vertical bore-hole was developed and applied at three study areas, which contain four sites composed of two existing port sites and two new LNG storage facility sites. The geotechnical dynamic properties such as VS, VP and v with depth were efficiently determined from the laterally impacted cross-hole seismic tests at study sites, and were provided as the fundamental parameters for the seismic performance evaluation of the existing ports and the seismic design of the LNG storage facilities.

  • PDF

Microstrip Resonator for Simultaneous Application to Filter and Antenna (여파기와 안테나로 동시 적용이 가능한 마이크로스트립 공진기)

  • Sung, Young-Je;Kim, Duck-Hwan;Kim, Young-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.21 no.5
    • /
    • pp.475-485
    • /
    • 2010
  • This paper proposes a novel concept for a microstrip resonator that can function as a filter and as an antenna at the same time. The proposed structure consists of an outer ring, an open loop-type inner ring, a circular patch, and three ports. The frequencies where the proposed structure works as a filter and as an antenna, respectively, are determined primarily by the radius of the inner ring and the circular patch. The measured results show that, when the microstrip resonator operates as a filtering device, this filter has about 15.1 % bandwidth at the center frequency of 0.63 GHz and a minimum insertion loss of 1.5 dB within passband. There are three transmission zeros at 0.52 GHz, 1.14 GHz, and 2.22 GHz. In the upper stopband, cross coupling - taking place at the stub of the outer ring - and the open loop-type inner ring produce one transmission zero each. The circular patch generates the dual-mode property of the filter and another transmission zero, whose location can be easily adjusted by altering the size of the circular patch. The proposed structure works as an antenna at 2.7 GHz, showing a gain of 3.8 dBi. Compared to a conventional patch antenna, the proposed structure has a similar antenna gain. At the resonant frequencies of the filter and the antenna, high isolation(less than -25 dB) between the filter port and the antenna port can be obtained.