• 대한간호학회지
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• 제25권2호
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• pp.351-361
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• 1995

The main purpose of the study is to identify critical risk factors for development of a family assessment tool to screen high risk family. This study used a conceptual framework of family diagnosis developed by Eui-sook Kim's (1993) and analyzed risk factors to identify the high risk family. As employing a explorative and methodological study design, this study has four stages. 1. In the first stage, 34 family risk factors were identified by doing intensive literature review on conceptual framework of family diagnoses. 2. In the second stage, above risk factors were tested for content validity by consultation with 29 persons in community health nursing, nursing education, family theory, and social work. 3. In the third stage, existing survey data was used for actual application of the identified risk factors. The survey data used for this purpose was previously collected for the community diagnosis in a region of Seoul. At the final stage, through the comparison between high risk and low risk families, initially identified 34 risk factors decreased to 25 risk factors. Among 34 risk factors, six factors did not agree with content of questionnaries sand two factors were not significant in differentiating the high risk family Also, two risk factors showed high correlation between themselves, so only one of those two factors was chosen. As a result, twenty-five risk factors chosen to identify the high risk family are following ; 1. A single parent family due to divorce or death of a partner, or unweded single mother 2. A family with an unrelated household members 3. A family with a working mother with a young child 4. A family with no regular income 5. A family with no rule in family or too strict rules 6. A family with little or no support from other lam-ily members 7. A family with little or no support from friends or relatives 8. A family with little or no time to share with each other 9. A family with family history of hypertension, diabetus, cancer 10. A family with a sick person 11. A family with a mentally ill person 12. A family with a disabled person 13. A family with an alcoholic person 14. A family with a excessive smoker who smokes more than 1 pack / day 15. A family with too much salt intake in their diet. 16. A family with inappropriate management skills for family health 17. A family with high utilization of drug store than hospital to solve the health problems of the family 18. A family with disharmony between husband and wife 19. A family with conflicts among the family members 20. A family with unequal division of labor among family members 21. An authoritative family structure 22. A socially isolated family 23. The location of house is not residential area 24. A family with high risk of accidents 25. The drinking water and sewage systems are not hygienic. The main implication of the results of this study is clinical use. The high risk factors can be used to identify the high risk family effectively and efficiently. The use of high risk factors woule contribute to develop a conceptual framework of family diagnosis in Korea and the list of risk factors need to be revised continuously. Further researches are needed to develop an index of weight of each risk factor and to validate the risk factors.

• 천문학회보
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• 제35권2호
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• pp.49.2-49.2
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• 2010

In order to understand the configuration of magnetic field producing a solar penumbral microjet that was recently discovered by Hinode, we performed a magnetohydrodynamic simulation reproducing a dynamic process of how that configuration is formed in a modeled solar penumbral region. A horizontal magnetic flux tube representing a penumbral filament is placed in a stratified atmosphere containing the background magnetic field that is directed in a relatively vertical direction. Between the flux tube and the background field there forms the intermediate region in which the magnetic field has a transitional configuration, and the simulation shows that in the intermediate region magnetic reconnection occurs to produce a clear jet- like structure as suggested by observations. The result that a continuous distribution of magnetic field in three-dimensional space gives birth to the intermediate region producing a jet presents a new view about the mechanism of a penumbral microjet, compared to a simplistic view that two field lines, one of which represents a penumbral filament and the other the background field, interact together to produce a jet. We also discuss the role of the intermediate region in protecting the structure of a penumbral filament subject to microjets.

• Industrial Engineering and Management Systems
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• 제9권2호
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• pp.178-194
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• 2010

To improve the ship operation in automated container terminals, it is important to schedule different types of handling equipment to operate synchronously. For example, a vehicle with container receiving and lifting capabilities is used to transport containers from a storage yard to a vessel and vice versa, while a triple quay crane (QC) can handle up to three 40-ft containers simultaneously. This paper discusses the manner in which vehicles should be assigned to containers to support such multi-lifts of QCs by using information about the locations and times of deliveries. A mixed-integer programming model is introduced to optimally assign delivery tasks to vehicles. This model considers the constraint imposed by the limited buffer space under each QC. A procedure for converting buffer-space constraints into time window constraints and a heuristic algorithmfor overcoming the excessive computational time required for solving the mathematical model are suggested. A numerical experiment is conducted to compare the objective values and computational times of the heuristic algorithm with those of the optimizing method to evaluate the performance of the heuristic algorithm.

• Journal of Mechanical Science and Technology
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• 제16권11호
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• pp.1379-1394
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• 2002

In case of a single input single output (SISO) system with a nonlinear term, a signal compression method is useful to identify a system because the equivalent impulse response of linear part from the system can be extracted by the method. However even though the signal compression method is useful to estimate uncertain parameters of the system, the method cannot be directly applied to a unique system with hysteresis characteristics because it cannot estimate all of the two different dynamic properties according to its motion direction. This paper proposes a signal compression method with a pre-processor to identify a unique system with two different dynamics according to its motion direction. The pre-processor plays a role of separating expansion and retraction properties from the system with hysteresis characteristics. For evaluating performance of the proposed approach, a simulation to estimate the assumed unknown parameters for an arbitrary known model is carried out. A motion platform with several single-rod cylinders is a representative unique system with two different dynamics, because each single-rod cylinder has expansion and retraction dynamic properties according to its motion direction. The nominal constant parameters of the motion platform are experimentally identified by using the proposed method. As its application, the identified parameters are applied to a design of a sliding mode controller for the simulator.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.531-536
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• 2003

In this paper, a redesigned guidance and control system for a lunar lander is presented. In past studies, the authors developed a trajectory and attitude control system which achieves the vertical soft landing on the lunar surface. It is confirmed that the system has a good tracking ability to a predefined profile and good robustness against a thruster failure mode where a partial failure of clustered engines was assumed. However, under the previous control laws, the landing point tends to be shifted, in response to the system parameter values, from a target point. Also, an unbalanced moment due to a thruster failure mode was not considered in the simulation. Therefore, in this study, the downrange control is added to the system to enable the vehicle to land at a pre-assigned target point accurately. Furthermore, inhibiting the effect of the unbalanced moment is attempted thorough redesigning the attitude control system. A numerical simulation was performed to confirm the ability of the proposed system with regard to the above problems. Moreover, in the past simulations, a low initial altitude was assumed as an initial condition: in this study, however, the performance of the proposed system is examined over the whole trajectory from an initial altitude of 10 [km] to the lunar surface.

• ETRI Journal
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• 제36권1호
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• pp.51-61
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• 2014

In the Mobile IPv6 (MIPv6) protocol, a mobile node (MN) is a mobile device with a permanent home address (HoA) on its home link. The MN will acquire a care-of address (CoA) when it roams into a foreign link. It then sends a binding update (BU) message to the home agent (HA) and the correspondent node (CN) to inform them of its current CoA so that future data packets destined for its HoA will be forwarded to the CoA. The BU message, however, is vulnerable to different types of security attacks, such as the man-in-the-middle attack, the session hijacking attack, and the denial-of-service attack. The current security protocols in MIPv6 are not able to effectively protect the BU message against these attacks. The private-key-based BU (PKBU) protocol is proposed in this research to overcome the shortcomings of some existing MIPv6 protocols. PKBU incorporates a method to assert the address ownership of the MN, thus allowing the CN to validate that the MN is not a malicious node. The results obtained show that it addresses the security requirements while being able to check the address ownership of the MN. PKBU also incorporates a method to verify the reachability of the MN.

• 통상정보연구
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• 제7권4호
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• pp.157-177
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• 2005

In many countries, a Single Window system for simplifications is establishing in order to reduce works submitted double data and compliance costs. A Single Window is defined as a facility that allows parties involved in trade and transport to lodge standardized information and documents with a single entry point to fulfil all import, export, and transit-related regulatory requirements. A Single window can bring improved level of security, faster clearance and reduced compliance costs. UN/CEFACT released "Recommendation and Guidelines on establishing a Single Window to enhance the efficient exchange of information between trade and government". Also, WCO has made progress several projects to assist effective establishing a single window, i.e. CDM, UCR, ICT. Korea has being established a single window system, "e-trade platform" connected with trade, clearance, logistics, marketing and payment system. Some suggestions to establish a effective single window system in Korea are as follows. Firstly, it is necessary to clearly define roles and responsibilities of a lead agency in a single window system and form a organic relationship with PGA. Secondly, a single window system has to be progressed by stages, namely, customs clearance portal system should be established first, and later established e-trade platform. Lastly, the Korean government has to take part in CDM project to gain an advantage over other countries.

• Industrial Engineering and Management Systems
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• 제11권3호
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• pp.276-287
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• 2012

Determining storage locations of containers is an important issue for efficient operation of container terminals. This study assumes a storage yard with a horizontal layout in which blocks are laid out in parallel to the quay and trucks enter at the side of a block to deliver (receive) a container to (from) the yard crane. Various storage rules for determining storage locations of containers are introduced. Simulation studies are conducted for evaluating various rules. The following guidelines are derived from the result of our simulation study: when designing a block, consider a block configuration in which the longest gantry and the longest trolley travel times of rail-mounted gantry cranes (RMGCs) are similar; do not restrict the types of containers that can be stored in a storage area; if different roles are to be assigned to different storage areas, one possible way is to divide a bay into two areas so that some rows in the bay are allocated to inbound containers while the other rows in the same bay are allocated to outbound containers; reserve the space in bay unit for a high productivity of RMGCs but reserve the space in stack unit when the storage space is not enough; when the storage space is not sufficient, allocate storage location in a way of starting from the end and ending at the middle of a block; for reducing the travel distance of internal trucks, provide a higher priority to a block nearer to the berthing position of the corresponding vessel.

• 한국치위생학회지
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• 제9권2호
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• pp.179-191
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• 2009

The purpose of this study was to examine the needs of dental hygiene students at a lifelong education center of a three-year-course college for a credit bank system. The subjects in this study were 200 dental hygiene students at a college located in J, which offered courses of a credit bank system. A survey was conducted from May 19 to 23, 2008, to gather data on the acquisition of a bachelor's degree and the credit bank system, and the answer sheets from 184 respondents(92%) were collected. After the collected data were analyzed with SPSS/WIN 12.0 program, the following findings were given: 1. In regard to an intention of taking a bachelor's degree, the largest number of the students investigated(74.5%) intended to do that if they had any chance. As for the reason, 55.6% wanted to get the degree in pursuit of their own personal development. 2. Concerning how to win a bachelor's degree, the largest group that accounted for 63.0% preferred the credit bank systems of college lifelong education centers. 41.8% got interested in the credit bank system mainly because their acquaintances informed them of it. It shows that colleges should reinforce publicity activities if they want to offer the credit bank system. 3. The quality of educational programs and cost had an impact on the choice of an educational institution when they planned to get a bachelor's degree from the credit bank system. Therefore excellent educational programs should be provided, and the government should provide learners with economic help and fund educational institutions. 4. As to comparison of a regular college and the credit bank system as a way to get a bachelor's degree, that was considered to be helpful for finding a job(a mean of 3.39) and for the development of sociability(3.22). That was also deemed to be of use for the improvement of practical job performance, to win public recognition and to be helpful for being well-cultivated, though not many students had those opinions. They took a different view according to academic year(p<.05). 5. Regarding the expected effects of getting a degree from the credit bank system, the greatest group expected it to step up their personal development(3.85). The second largest group expected it to boost job efficacy(3.30), and the students whose academic year was higher had a better opinion. 6. As for future directions for the credit bank system, the largest group put emphasis on the improvement of social perception through intensive P.R. and the enhancement of the qualifications of professors and lecturers(4.02). These opinions were more stressed by the juniors than by the sophomores and seniors, and academic year made a significant difference to their views(p<.05).

• 대한음성학회지:말소리
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• 제27_28호
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• pp.27-56
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• 1994

Processes involving the change of vowel height are natural enough to be found in many languages. It is essential to have a better feature specification for vowel height to grasp these processes properly, Standard Phonology adopts the binary feature system, and vowel height is represented by the two features, i.e., [\pm high] and [\pm low]. This has its own merits. But it is defective because it is misleading when we count the number of features used in a rule to compare the naturalness of rules. This feature system also cannot represent more than three degrees of height, We wi31 discard the binary features for vowel height. We consider to adopt the multivalued feature [n high] for the property of height. However, this feature cannot avoid the arbitrariness resulting from the number values denoting vowel height. It is not easy to expect whether the number in question is the largest or not It also is impossible to decide whether a larger number denotes a higher vowel or a lower vowel. Furthermore this feature specification requires an ad hoc condition such as n > 3 or n \geq 2, whenever we want to refer to a natural class including more than one degree of height The altelnative might be Particle Phonology, or Dependency Phonology. These might be apt for multivalued vowel height systems, as their supporters argue. However, the feature specification of Particle Phonology will be discarded because it does not observe strictly the assumption that the number of the particle a is decisive in representing the height. One a in a representation can denote variant degrees of height such as [e], [I], [a], [a ] and [e ]. This also means that we cannot represent natural classes in terms of the number of the particle a, Dependency Phonology also has problems in specifying a degree of vowel height by the dependency relations between the elements. There is no unique element to represent vowel height since every property has to be defined in terms of the dependency relations between two or more elements, As a result it is difficult to formulate a rule for vowel height change, especially when the phenomenon involves a chain of vowel shifts. Therefore, we suggest a new feature specification for vowel height (see Chapter 3). This specification resorts to a single feature H and a few >'s which refer exclusively to the degree of the tongue height when a vowel is pronounced. It can cope with more than three degrees of height because it is fundamentally a multivalued scalar feature. This feature also obviates the ad hoc condition for a natural class while the [n high] type of multivalued feature suffers from it. Also this feature specification conforms to our expection that the notation should become simpler as the generality of the class increases, in that the fewer angled brackets are used, the more vowels are included, Incidentally, it has also to be noted that, by adopting a single feature for vowel height, it is possible to formulate a simpler version of rules involving the changes of vowel height especially when they involve vowel shifts found in many languages.