• Title/Summary/Keyword: risk free zone

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Risk free zone study for cylindrical objects dropped into the water

  • Xiang, Gong;Birk, Lothar;Li, Linxiong;Yu, Xiaochuan;Luo, Yong
    • Ocean Systems Engineering
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    • v.6 no.4
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    • pp.377-400
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    • 2016
  • Dropped objects are among the top ten causes of fatalities and serious injuries in the oil and gas industry (DORIS, 2016). Objects may accidentally fall down from platforms or vessels during lifting or any other offshore operation. Proper planning of lifting operations requires the knowledge of the risk-free zone on the sea bed to protect underwater structures and equipment. To this end a three-dimensional (3D) theory of dynamic motion of dropped cylindrical object is expanded to also consider ocean currents. The expanded theory is integrated into the authors' Dropped Objects Simulator (DROBS). DROBS is utilized to simulate the trajectories of dropped cylinders falling through uniform currents originating from different directions (incoming angle at $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, and $270^{\circ}$). It is found that trajectories and landing points of dropped cylinders are greatly influenced by the direction of current. The initial conditions after the cylinders have fallen into the water are treated as random variables. It is assumed that the corresponding parameters orientation angle, translational velocity, and rotational velocity follow normal distributions. The paper presents results of DROBS simulations for the case of a dropped cylinder with initial drop angle at $60^{\circ}$ through air-water columns without current. Then the Monte Carlo simulations are used for predicting the landing point distributions of dropped cylinders with varying drop angles under current. The resulting landing point distribution plots may be used to identify risk free zones for offshore lifting operations.

Mitigation of Ammonia Dispersion with Mesh Barrier under Various Atmospheric Stability Conditions

  • Gerdroodbary, M. Barzegar;Mokhtari, Mojtaba;Bishehsari, Shervin;Fallah, Keivan
    • Asian Journal of Atmospheric Environment
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    • v.10 no.3
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    • pp.125-136
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    • 2016
  • In this study, the effects of the mesh barrier on the free dispersion of ammonia were numerically investigated under different atmospheric conditions. This study presents the detail and flow feature of the dispersion of ammonia through the mesh barrier on various free stream conditions to decline and limit the toxic danger of the ammonia. It is assumed that the dispersion of the ammonia occurred through the leakage in the pipeline. Parametric studies were conducted on the performance of the mesh barrier by using the Reynolds-averaged Navier-Stokes equations with realizable k-${\varepsilon}$ turbulence model. Numerical simulations of ammonia dispersion in the presence of mesh barrier revealed significant results in a fully turbulent free stream condition. The results clearly show that the flow behavior was found to be a direct result of mesh size and ammonia dispersion is highly influenced by these changes in flow patterns in downstream. In fact, the flow regime becomes laminar as flow passes through mesh barrier. According to the results, the mesh barrier decreased the maximum concentration of the ammonia gas and limited the risk zone (more than 500 ppm) lower than 2 m height. Furthermore, a significant reduction occurs in the slope of the upper boundary of $NH_3$ risk zone distribution at downstream when a mesh barrier is presented. Thus, this device highly restricts the leak distribution of ammonia in the industrial plan.

INCOTERMS 2000 and Maritime Term (INCOTERMS 2000과 해상매매조건(海上賣買條件))

  • Oh, Won-Suk
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.13
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    • pp.105-129
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    • 2000
  • INCOTERMS 2000 was not changed in its basic system but much improved in many minor aspects, reflecting the expansion of customs free zone, the spread of electronic communications and the changes of transportation practices. Among many points, following revisions are to be considered important to examine : First, the term 'delivery' is clearly defined in the preamble of each term, which is very significant since the risk is connected with the delivery in international trade. Second, the obligation of carrying out export customs formalities in FAS and import customs formalities in DEQ are imposed to seller and buyer respectively according to current trade practices. Third, since the customs formalities are no more needed among the countries of customs free zone, the phrase 'where applicable' is inserted in A.2 and B.2 of each term. Fourth, the method of delivery(for example, loaded or unloaded) became very concrete and clear in each term. Fifth, in the obligation of buyer's contracting insurance, the 'no obligation' is added even though the buyer has no insurance obligation to the seller. Finally the I.C.C. tried to make unification of the special terminologies be in accordance with those of CISG to achieve international harmony between the uniform law and uniform usages.

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Implementation of ATmega128 based Short Message Transmission Protocol IMCP (ATmega128 기반 단문 메시지 전송 프로토콜 IMCP 구현)

  • Kim, Jeom Go
    • Convergence Security Journal
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    • v.20 no.3
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    • pp.3-11
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    • 2020
  • The social networking service (SNS) is free, but the data usage fee paid to the telecommunications company and the member's information must be provided directly or indirectly. In addition, while SNS' specifications for transmitting and receiving devices such as smart-phones and PCs are increasing day by day, using universal transmission protocols in special environments such as contaminated areas or semiconductor manufacturing plants where work instructions are mainly made using short messages is not easy. It is not free and has a problem of weak security. This paper verified the practicality through the operation test by implementing IMCP, a low-power, low-cost message transmission protocol that aims to be wearable in special environments such as risk, pollution, and clean zone based on ATmega128.

A Research on Legal Risk Prevention of Chinese enterprises' FDI in China-Japan-Korea FTA

  • SU, Shuai;ZHANG, Fan
    • The Journal of Economics, Marketing and Management
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    • v.7 no.4
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    • pp.6-9
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    • 2019
  • Purpose - This research mainly studied with the promotion of "one belt and one road "initiative's strategy and the construction of China, Japan and South Korea Free Trade Zone, China exports urgently needed industrial products to Japan and South Korea, which will not only help digest excess industrial capacity, optimize China's industrial structure, but also promote the economic development of Japan and South Korea. Research design, data, and Methodology - The study conducted a survey on 2018 year new revision of China-Korea Japan's data. Results -This study shows that In this process, multinational enterprises, as pioneers of economic development, play an irreplaceable role. However, due to the differences between laws of different countries and their own corporate culture concepts, enterprises in different countries will inevitably encounter various conflicts in the process of development. Conclusions -This requires our enterprises to have awareness of legal risk prevention in the process of development, and to study the corporate culture of relevant enterprises to truly achieve win-win cooperation.

Clinical presentation and treatment outcomes of primary ocular adnexal MALT lymphoma in Thailand

  • Seresirikachorn, Kasem;Norasetthada, Lalita;Ausayakhun, Sakarin;Apivatthakakul, Atitaya;Tangchittam, Sirima;Pruksakorn, Vannakorn;Wudhikarn, Kitsada;Wiwatwongwana, Damrong
    • BLOOD RESEARCH
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    • v.53 no.4
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    • pp.307-313
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    • 2018
  • Background Primary ocular adnexal extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (POML) is the most common subtype of lymphoma involving the eyes in Thailand. We sought to assess the characteristics and treatment outcomes of patients with POML in Thailand. Methods We retrospectively reviewed patient data and included patients diagnosed with POML between January 2004 and December 2016 at Chiang Mai University Hospital and King Chulalongkorn Memorial Hospital, Thailand. We collected and analyzed patients' clinical characteristics and treatment outcomes. Results Among 146 patients with lymphoma involving the eyes, 121 (82%) were diagnosed with POML. Sixty-four (52.9%) were women with median age 58 (range, 22-86) years. The most common presenting symptom was orbital mass (71.1%). Common sites of origin were the orbit (46.3%) and lacrimal gland (34.7%). At presentation, 22.3% of patients had bilateral eye involvement. About half of patients had stage I disease (N=59, 56.2%) and 20% had stage IV. Most patients (73.3%) had a low-risk International Prognostic Index. Radiotherapy was the main treatment for patients with limited-stage disease (66.7% in stage I and 56.5% in stage II). The overall response rate was 100% with complete response rates 80%, 77.3%, and 64.7% for stages I, II, and IV, respectively. Five-year progression-free survival (PFS) and overall survival were 66.1% and 94.0%, respectively. For patients with limited-stage disease, radiotherapy significantly improved PFS compared with treatment not involving radiotherapy (5-year PFS 89.9% vs. 37.3%, P=0.01). Conclusion We revealed that POML has good response to treatment, especially radiotherapy, with excellent long-term outcome.

Porewater Pressure Predictions on Hillside Slopes for Assessing Landslide Risks (II) Development of Groundwater Flow Model (산사태 위험도 추정을 위한 간극수압 예측에 관한 연구(II) -산사면에서의 지하수위 예측 모델의 개발-)

  • Lee, In-Mo;Park, Gyeong-Ho;Im, Chung-Mo
    • Geotechnical Engineering
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    • v.8 no.2
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    • pp.5-20
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    • 1992
  • The physical-based and lumped-parameter hydrologic groundwater flow model for predicting the rainfall-triggered rise of groundwater levels in hillside slopes is developed in this paper to assess the risk of landslides. The developed model consists of a vertical infiltration model for unsaturated zone linked to a linear storage reservoir model(LSRM) for saturated zone. The groundwater flow model has uncertain constants like soil depttL slope angle, saturated permeability, and potential evapotranspiration and four free model parameters like a, b, c, and K. The free model parameters could be estimated from known input-output records. The BARD algorithm is uses as the parameter estimation technique which is based on a linearization of the proposed model by Gauss -Newton method and Taylor series expansion. The application to examine the capacity of prediction shows that the developed model has a potential of use in forecast systems of predicting landslides and that the optimal estimate of potential 'a' in infiltration model is the most important in the global optimum analysis because small variation of it results in the large change of the objective function, the sum of squares of deviations of the observed and computed groundwater levels. 본 논문에서는 가파른 산사면에서 산사태의 발생을 예측하기 위한 수문학적 인 지하수 흐름 모델을 개발하였다. 이 모델은 물리적인 개념에 기본하였으며, Lumped-parameter를 이용하였다. 개발된 지하수 흐름 모델은 두 모델을 조합하여 구성되어 있으며, 비포화대 흐름을 위해서는 수정된 abcd 모델을, 포화대 흐름에 대해서는 시간 지체 효과를 고려할 수 있는 선형 저수지 모델을 이용하였다. 지하수 흐름 모델은 토층의 두께, 산사면의 경사각, 포화투수계수, 잠재 증발산 량과 같은 불확실한 상수들과 a, b, c, 그리고 K와 같은 자유모델변수들을 가진다. 자유모델변수들은 유입-유출 자료들로부터 평가할 수 있으며, 이를 위해서 본 논문에서는 Gauss-Newton 방법을 이용한 Bard 알고리즘을 사용하였다. 서울 구로구 시흥동 산사태 발생 지역의 산사면에 대하여 개발된 모델을 적용하여 예제 해석을 수행함으로써, 지하수 흐름 모델이 산사태 발생 예측을 위하여 이용할 수 있음을 입증하였다. 또한, 매개변수분석 연구를 통하여, 변수 a값은 작은 변화에 대하여 목적함수값에 큰 변화를 일으키므로 a의 값에 대한 최적값을 구하는 것이 가장 중요한 요소라는 결론을 얻었다.

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Simulation of Ultrasonic Stress During Impact Phase in Wire Bonding

  • Mayer, Michael
    • Journal of the Microelectronics and Packaging Society
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    • v.20 no.4
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    • pp.7-11
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    • 2013
  • As thermosonic ball bonding is developed for more and more advanced applications in the electronic packaging industry, the control of process stresses induced on the integrated circuits becomes more important. If Cu bonding wire is used instead of Au wire, larger ultrasonic levels are common during bonding. For advanced microchips the use of Cu based wire is risky because the ultrasonic stresses can cause chip damage. This risk needs to be managed by e.g. the use of ultrasound during the impact stage of the ball on the pad ("pre-bleed") as it can reduce the strain hardening effect, which leads to a softer deformed ball that can be bonded with less ultrasound. To find the best profiles of ultrasound during impact, a numerical model is reported for ultrasonic bonding with capillary dynamics combined with a geometrical model describing ball deformation based on volume conservation and stress balance. This leads to an efficient procedure of ball bond modelling bypassing plasticity and contact pairs. The ultrasonic force and average stress at the bond zone are extracted from the numerical experiments for a $50{\mu}m$ diameter free air ball deformed by a capillary with a hole diameter of $35{\mu}m$ at the tip, a chamfer diameter of $51{\mu}m$, a chamfer angle of $90^{\circ}$, and a face angle of $1^{\circ}$. An upper limit of the ultrasonic amplitude during impact is derived below which the ultrasonic shear stress at the interface is not higher than 120 MPa, which can be recommended for low stress bonding.

Validity and Pertinence of Administrative Capital City Proposal (행정수도 건설안의 타당성과 시의성)

  • 김형국
    • Journal of the Korean Geographical Society
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    • v.38 no.2
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    • pp.312-323
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    • 2003
  • This writer absolutely agrees with the government that regional disequilibrium is severe enough to consider moving the administrative capital. Pursuing this course solely to establish a balanced development, however, is not a convincing enough reason. The capital city is directly related to not only the social and economic situation but, much more importantly, to the domestic political situation as well. In the mid-1970s, the proposal by the Third Republic to move the capital city temporarily was based completely on security reasons. At e time, the then opposition leader Kim, Dae-jung said that establishing a safe distance from the demilitarized zone(DMZ) reflected a typically military decision. His view was that retaining the capital city close to the DMZ would show more consideration for the will of the people to defend their own country. In fact, independent Pakistan moved its capital city from Karachi to Islamabad, situated dose to Kashmir the subject of hot territorial dispute with India. It is regrettable that no consideration has been given to the urgent political situation in the Korean peninsula, which is presently enveloped in a dense nuclear fog. As a person requires health to pursue his/her dream, a country must have security to implement a balanced territorial development. According to current urban theories, the fate of a country depends on its major cities. A negligently guarded capital city runs the risk of becoming hostage and bringing ruin to the whole country. In this vein, North Koreas undoubted main target of attack in the armed communist reunification of Korea is Seoul. For the preservation of our state, therefore, it is only right that Seoul must be shielded to prevent becoming hostage to North Korea. The location of the US Armed Forces to the north of the capital city is based on the judgment that defense of Seoul is of absolute importance. At the same time, regardless of their different standpoints, South and North Korea agree that division of the Korean people into two separate countries is abnormal. Reunification, which so far has defied all predictions, may be realized earlier than anyone expects. The day of reunification seems to be the best day for the relocation of the capital city. Building a proper capital city would take at least twenty years, and a capital city cannot be dragged from one place to another. On the day of a free and democratic reunification, a national agreement will be reached naturally to find a nationally symbolic city as in Brazil or Australia. Even if security does not pose a problem, the governments way of thinking would not greatly contribute to the balanced development of the country. The Chungcheon region, which is earmarked as the new location of the capital city, has been the greatest beneficiary of its proximity to the capital region. Not being a disadvantaged region, locating the capital city there would not help alleviate regional disparity. If it is absolutely necessary to find a candidate region at present, considering security, balanced regional development and post-reunification scenario of the future, Cheolwon area located in the middle of the Korean peninsula may be a plausible choice. Even if the transfer of capital is delayed in consideration of the present political conflict between the South and the North Koreas, there is a definite shortcut to realizing a balanced regional development. It can be found not in the geographical dispersal of the central government, but in the decentralization of power to the provinces. If the government has surplus money to build a new symbolic capital city, it is only right that it should improve, for instance, the quality of drinking water which now everyone eschews, and to help the regional subway authority whose chronic deficit state resoled in a recent disastrous accident. And it is proper to time the transfer of capital city to coincide with that of the reunification of Korea whenever Providence intends.