• Journal of Ship and Ocean Technology
• /
• v.10 no.4
• /
• pp.1-11
• /
• 2006

The finite volume based multi-block RANS code, WAVIS developed at MOERI is applied to the numerical self-propulsion test. WAVIS uses the cell-centered finite volume method for discretization of the governing equations. The realizable $k-{\epsilon}$ turbulence model with a wall function is employed for the turbulence closure. The free surface is captured with the two-phase level set method and body forces are used to model the effects of a propeller without resolving the detail blade flow. The propeller forces are obtained using an unsteady lifting surface method based on potential flow theory. The numerical procedure followed the self-propulsion model experiment based on the 1978 ITTC performance prediction method. The self-propulsion point is obtained iteratively through balancing the propeller thrust, the ship hull resistance and towing force that is correction for Reynolds number difference between the model and full scale. The unsteady lifting surface code is also iterated until the propeller induced velocity is converged in order to obtain the propeller force. The self-propulsion characteristics such as thrust deduction, wake fraction, propeller efficiency, and hull efficiency are compared with the experimental data of the practical container ship. The present paper shows that hybrid RANS and potential flow based numerical method is promising to predict the self-propulsion parameters of practical ships as a useful tool for the hull form and propeller design.

• Journal of Navigation and Port Research
• /
• v.33 no.5
• /
• pp.309-314
• /
• 2009

The influence of different appendage shape on the characteristics of hydrodynamic forces on Manta-type Unmanned Undersea Test Vehicle(MUUTV) was discussed experimentally. Fuselage only MUUTV model and two types of MUUTV model with different appendage geometries were considered as the subject of discussion Oblique tow experiment was carried out in circulating water channel with three MUUTV models. A point of difference in hydrodynamic force characteristics among three models was indicated. Furthermore, the linear hydrodynamic derivatives obtained from model experiment were compared with theoretical calculation results from slender body theory, added mass theory and etc. Based on the hydrodynamic force characteristics, motion stability of two types of MUUTV model with different appendage geometries was compared each other. Through the above analysis, the more suitable shape of appendage geometry was made clear.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2009.06a
• /
• pp.5-6
• /
• 2009

The influence of different appendage shape on the characteristics of hydrodynamic forces on Manta-Type Unmanned Undersea Test Vehicle(MUUTV) was discussed experimentally. Fuselage only MUUTV model and two types of MUUTV model with different appendage geometries were considered as subject of discussion Oblique tow experiment was carried out in circulating water channel with three MUUTV models. A point of difference in hydrodynamic force characteristics among three models was compared and discussed. Furthermore, the linear hydrodynamic derivatives obtained from model experiment were compared with theoretical calculation results from slender body theory, added mass theory and ete. Based on the hydrodynamic force characteristics, motion stability of two types of MUUTV model with different appendage geometries was discussed and compared each other. Through the above analysis, the more suitable shape of appendage geometry was made clear.

• International Commerce and Information Review
• /
• v.8 no.4
• /
• pp.209-227
• /
• 2006

This paper analyse current interpretation of the "causal link" that in particular, focuses principally on the so-called "non-attribution" requirement of Article 4.2(b) of the Safeguards Agreement. The safeguard measures are justified as a temporary economic adjustment to harm that is caused by an increase in imports. The problem with this justification is that there are other kinds of economic forces that may injure domestic industries, such as changes in consumer tastes, government spending or a lack thereof, and economic downturns. These problems do not justify government-imposed remedies. When factors therefore other than increased imports are causing injury to the domestic industry at the same time, such injury shall not be attributed to increased imports. The Appellate Body stressed that a contribution of third-party imports to the existence of serious injury must be sufficiently clear as to establish the existence of the causal link required, it found that Article 4.2(b) does not suggest that increased imports be the sole cause of the serious injury, or that other factors causing injury must be excluded from the determination of serious injury. The interest in separation is to ensure that a measure is not applied to remedy harm not caused by imports, but this basic point assumes that the harm is distinguishable in the first place. It also assumes that the safeguard is designed to respond to harm caused by imports. In fact safeguards were never intended to respond to this kind of unfair trade, but rather to provide whatever emergency relief might assist an ailing domestic industry if imports happened to be a part of that injury. The Appellate Body's insistence in breaking cause and effect down to minutia in the non-attribution analysis seems to be so overly intricate that it conflicts with it's broader focus on evaluating factors that effect harm on the industry as a whole.

• Journal of Korean Philosophical Society
• /
• v.142
• /
• pp.145-164
• /
• 2017

In his Phenomenology of Perception, Merleau-Ponty raises a question of why he has to ask what phenomenology is again. This study assumes that the question can be answered in a new understanding of the "nature" concept and finds its possible grounds in the nature concepts of Schelling and Merleau-Ponty. Schelling and Merleau-Ponty develop philosophical thinking from a critical point of view on the Cartesian and Kantian philosophies "Thing-in-itself" by Kant is, in particular, one of important questions that has to be answered in the philosophy of Schelling since Kant further solidifies a dualistic world by leaving thing-in-itself. Schelling solves the question with the concept of identity and Merleau-Ponty solves the question with body-subject. What we notice in this article is the understanding of Shelling and Merleau-Ponty about nature. Schelling believes there are the creative activities of unconscious intelligence in nature, but spirit or intelligence in his nature concept cannot induce an existential being. Here we see that Schelling is still beyond the traditional epistemological framework. To restore the original nature of nature, we must begin with an understanding of the totality of nature. Nature must also be explained through relationships with humans. Merleau-Ponty shows the entanglement of nature and spirit through the body-subject. In Merleau-Ponty's phenomenology, the body is the equivalent of nature. Understanding the forces of nature that Schelling and Merleau-Ponty are trying to show, and at the same time explaining the problem of how the mind or human beings emerge from nature, we will be able to discover the true nature of nature.

• Journal of Korean Academy of Nursing
• /
• v.23 no.1
• /
• pp.118-129
• /
• 1993

In order to approach the nursing care of clients who are using oriental medicine and to understand the perception of the client who uses oriental medicine practices and the need to develop a model of nursing related to oriental medicine it is important to examine the major nursing concepts as they are found in oriental medicine and as they are differently defined according to the basic thought, theory and philosophical perspectives between East and West. Oriental medicine developed based on Sung Confucianism the teachings of Chut-zu, especially Tai-Chi-Tu Shuo and energy thought which are similar to traditional Korean Sasang Constitutional medicine. The basic theory on which oriental medicine is build is the theory of the five elements of Yin / Eum-Yang Theory(cosmic dual forces) and Meridian Theory. The most important attribute of Yin Yang is the concept of duality, confrontation and dependence, within Yin Yang but which do not exist separately. That is, the universe is a vast, indivisible entity within which all things exist in harmonious interdependence and balance. Harmony is achieved only when the two primorial forces, Yin and Yang, are brought into perfect balance. Each is contained within the other and there is a continuing interchange between the two. This also applies to the human body including human health which is defined as balanced harmony. The most universal connection of Yin and Yang is found in the universe where the five elements of life, fire, water, earth, wood and metal can be explained as having either Yin or Yang and therefore being in a state of connectedness but systematically circulating between the two, that is essentalilly one (the control of the unified ) or as coexistant poles of individual wholes (the pluralism of Yin Yang Theory) so that it is all unified(balanced) in the Great Absoulte. Human beings also maintain a balance of Yin and Yang in the five elements and this relationship is very important in approaching ·oriental medicine, The meridians are the channels in the body through which the life force flow throughout the body. In oriental medicine the meridians are seen as the railroad, the acupuncture points on the meridians as the stations and energy as the train. In the normal healthy organism, all are maintained in balance and in a contiuous circulation of energy. illness is the result of the energy flow becoming disarranged. Although practitioners of oriental medicine approach the client differently than do practitioners of Western medicine and their method of examining the patient is different, the basic objectives of the examination are the same for practitioners of both types of medicine. Therefore if each could be used to supplement the defiencies in the other and achieve a harmonious cooperation between the two, a higher level of care which is culturally appropriate to korean culture could be achieved. The traditional korean concept of health is a naturalistic view which emphasizes being in harmony with nature. Any manifestation of disease is considered a sign that the body is in a state of disequilibrium and is thus no longer in harmony with the universe. The wholistic view of the world held by practitioners of oriental medicine can be used by nursing in the development of a world view of nursing in which the human being is seen within the macrocosm as part of the natural phenomenon of the universe and but also as a microcosm of the universe, a universe which is a vast and indivisible entity within which all things exist in harmonious interdependence and balance. Interaction between human beings and their environment and the relationship of this interaction to health are concepts that are also found in nursing. Nursing views human brings, not as an accumulation of separate cells and organs but, as unified wholes interacted in very close relationship nth their environment. Nursing also maintains a view of human beings in which emphasis is placed on the role of the mind in explaining the concepts of harmony and balance in health. Although there are differences between oriental medicine and nursing in approaches to clients, the basic point of view and philosophy have many fundamental similarites. An understanding of the basic thought and philosophy of oriental medicine if applied to nursing, would allow for the development, not only of nursing related to oriental medicine, but of a nursing theory appropriate to the korean context.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.22 no.4
• /
• pp.377-385
• /
• 2002

Ultrasonic tests employing non-ionizing radiation are preferred in nondestructive examinations since they are safe and simple in use. The same principles of the techniques have been taken as valuable tools in medical area for the diagnoses of diseases, in other words, defects of the human body. The paper overviews the principles of the medical diagnosis based on nondestructive ultrasonic tests, and then evaluates experimentally the clinical potential of C scan images not popular in medicine, for detecting the micro fractures of the cortical bone. In the experiment the micro bone fractures were created on the femurs of porks by loading three point bending forces (2-4kN) with the speed of 1 mm/min. As the extent of the fracture was altered, not only X ray images but also ultrasonic C scan images using a focused ultrasonic probe resonated at 25 MHz were obtained. The results showed that ultrasonic C scan images were capable of detecting the micro bone fractures which were not possible to identify by conventional X ray images.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.27 no.3
• /
• pp.193-210
• /
• 1991

For the deckhouse or superstructure, attention is directed to the reduction of vibration from a human susceptibility point of view. The two basic requirements for obtaining a low vibration level in the accommodation are to ensure that excitation forces from propeller and/or main engine are small and to avoid resonance excitation of the hull and superstructure. In recent years increased attention has been directed towards the problems of vibration and noise in deckhouse, which have caused major problems with regard to the environmental quality in the living quarters for crews. Accordingly, in this paper, the characteristic of the vibration of deckhouse of fishing boat, of which the length/height ratio is also relatively high, are studied systematically with regard to the shape and modelling of deckhouse based on finite element method of 1-dimensional, 2-dimensional and 3-dimensional model. This study is divided into 4-part. 1st part is the global deckhouse vibration, 2nd part is the local deckhouse vibration, 3rd part consists of the estimation for stiffness of foundational support and 4th part is the application to TUNA LONG LINER of 416 ton class. For the global vibration analysis, the severity of the vibration depends on the longitudinal shear and bending stiffness of the deckhouse, on the vertical deckhouse support(fore, aft and sides). However, even if the design is technically sound, vibration problems may arise due to vertical or longitudinal hull girder or afterbody resonances. Author applied the method of this study to the analysis of, deep-sea fishing vessel of G.T. 416 ton class with relatively low height and long deckhouse, and investigated the vibrational characteristic of the fishing vessel with earlier structural feature. According to this investigation, the vibration, response of above vessel was confirmed of which main hull and deckhouse behave as one body. It is at the bottom of vibrational trouble which a accommodation part of the fishing vessel is raised, that is the local vibration for side wall, fore-aft wall and deck plate of deckhouse rather than thief fect of fore-aft vibration of deckhouse for above fishing vessel. and the resonance of main hull, deckhouse and driving system such as the main engine, propeller in exciting source is mainly brought up as the trouble.

• Journal of Biosystems Engineering
• /
• v.39 no.1
• /
• pp.21-33
• /
• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• Journal of the Society of Naval Architects of Korea
• /
• v.53 no.5
• /
• pp.343-352
• /
• 2016

In this study, a pre-swirl duct for the 180,000 DWT bulk carrier has been designed from a propulsion standpoint using CFD. The stern duct - designed by NMRI - was selected as the initial duct. The objective function is to minimize the value of delivered power in model scale. Design variables of the duct include duct angle, diameter, chord length, and vertical and horizontal displacements from the center. Design variables of the stators are blade number, arrangement angle, chord length, and pitch angle. A parametric design was carried out with the objective function obtained using CFD. Reynolds averaged Navier-Stokes equations have been solved; and the Reynolds stress model applied for the turbulent closure. A double body model is used for the treatment of free-surface. MRF and sliding mesh models have been applied to simulate the actuating propeller. A self-propulsion point has been obtained from the results of towing and self-propelled computations, i.e., form factor obtained from towing computation and towing forces obtained from self-propelled computations of two propeller rotating speeds. The reduction rate of the delivered power of the improved stern duct is 2.9%, whereas that of the initial stern duct is 1.3%. The pre-swirl duct with one inner stator in upper starboard and three outer stators in portside has been designed. The delivered power due to the designed pre-swirl duct is reduced by 5.8%.