• Smart Structures and Systems
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• v.15 no.3
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• pp.831-846
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• 2015

Magneto-Rheological (MR) dampers are being used increasingly because of their adaptability to control algorithms and reliability of passive systems. In this paper, an extensive investigation on performance of MR dampers in semi-active and passive modes has been carried out. It is observed that the overall energy dissipation by MR dampers in passive-on modes is higher than that in semi-active modes for most of the competitive semi-active controllers. Based on the energy dissipation pattern, a novel semi-active controller, termed as "Simple Passive Semi-Active Controller", has been proposed for MR dampers. This controller can be emulated by a simple passive hardware proposed in this paper. The proposed concept of controller "hardware emulation" is innovative and can also be implemented for other semi-active devices for control algorithms of certain form. The effectiveness and reliability of the proposed controller has been investigated extensively through numerical simulations. It has been demonstrated that the proposed controller is competitive to or more effective than other widely used / investigated semi-active controllers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1656-1663
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• 2004

As the structures become larger, higher and more complicated, the demand for safety level has increased. In recent years, TLD(Tuned Liquid Damper) proved to be a successful control tool for reducing structural vibrations. For this reason, the influence of some key parameters of the U-type TLD on the dynamic response is studied. And simple and effectively developed learning control logic is used to control vibration of U type Tuned Liquid Damper system. The purpose of this paper is design optimal control system to deal with unknown errors from non linearity and variation that cost modeling difficulty in complex structure and is followed with the desired behavior. Finally this hybrid control method applied to U type Tuned Liquid Damper structure gives the benefit from better performance of precision and stability of the structure by reducing vibration effect. This research leads to safety design in various structure to robust unspecified foreign disturbances such as windy-load and earthquake.

• Korean Journal of Chemical Engineering
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• v.36 no.3
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• pp.356-367
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• 2019

This work presents an advanced and systematic approach to analytically design the optimal parameters of a two parameter second-order internal model control (IMC) filter that satisfies operational constraints on the output process, the manipulated variable as well as rate of change of the manipulated variable, for a first-order plus dead time (FOPDT) process. The IMC parameters are designed to minimize a control objective function composed of the weighted sum of the error between the process variable and the set point, and the rate of change of the manipulated variable, and to satisfy the desired constraints. The feasible region of the constrained IMC control parameters was graphically analyzed, as the process parameters and the constraints varied. The resulting constrained IMC control parameters were also used to find the corresponding industrial proportional-integral controller parameters of a Smith predictor structure.

• Health Policy and Management
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• v.32 no.3
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• pp.272-281
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• 2022

With the outbreak of coronavirus disease 2019 (COVID-19) pandemic, health policymakers are adopting new policies regarding the issue of immunization disparities, especially for children in low-income communities of color who lack awareness and thereby access to vaccines. The purpose of this paper is to propose an evaluation framework using program theory-based evaluation approach and logic model to analyze and evaluate the immunization disparities in children aged 19-35 months. Data is collected from New York City department of Health and the U.S. Census Bureau for Northern Manhattan Start Right Coalition program which consists of 19,800 children, and the community-provider partnership includes 26 practices and 20 groups. Program theory is used to evaluate this community-based initiative with the logic model which is a visual depiction that illustrations the program theory to all stakeholders. The logic model highlights the resources, activities, outputs, outcomes, and impacts of the program to guide to planners and evaluators and to call attention to the inadequacies or flaws in the operational, implementation and service delivery process of the program in offering a new perspective on the program. This framework adds to the literature on evaluations of immunization disparities in determining whether evaluators can definitively attribute positive immunization outcomes in the community to the program and conclude whether it has potential in expanding or duplicating it to other similar settings, especially in other rural areas of the United States, and abroad, where routine immunization equity gaps are wide due to income, racial and ethnic diversity, and language barrier.

• Lingua Humanitatis
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• v.1 no.2
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• pp.47-63
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• 2001

"A Variation of Love" is a characteristic Kim Soo-Young poem, in that it embodies the poet′s innovative use of language and proceeds speedily, like many of his other poems. Above all, the poem reveals the core of Kim′s poetical spirit, his speculation about love. The poem is difficult to understand because it broadly uses run-on lines and even run-on stanzas, a technique that many readers are unfamiliar with. The semiological approach of this paper will bring new light on the poem by restructuring the relationship between signs, that is, by taking apart the sign system of the original text and reconstructing its sentence structure. If we rearrange the poem from its original six stanzas and fifty-one lines to four stanzas and twenty-three lines, we will discover a close connection between stanzas 1 and 2, and between stanzas 3 and 4. Of the many keywords of the poem, we may establish the dominant word as "love," into which every poetic word converges and from which each word emanates. Another important keyword is "fatigue of the city" in stanza 4. Similarly negative aspects of the city may be found in the line "the same may be said of Bombay, of New York, of Seoul" in stanza 3, as well as in the words "desire" in combination with "the lamplights of Seoul like leftovers in the pig sty" in stanza 1. The persona of the poem tries to overcome the "fatigue of the city" by "love," but the way he realizes love is, somewhat peculiarly, through stillness and silence. The persona aligns "the stones of the peach and the apricot and the dried persimmon" with the his faith in love. He calls the stones "beautiful hardness" presumably because that hardness (the stillness and silence) may blossom into beauty. In the earlier stanzas, the persona′s quest for love results in an awareness that love is omnipresent, but the persona determines "not to shout it out loud." The reason for this determination is found in stanza 4. Those who experience the "fatigue of the city" will be able to realize it by themselves. This seemingly defeatist conclusion by no means suggest pessimism, for the persona holds the conviction that "there will come a day when [one] will rave for love." This conviction rescues the poem from the dismal mood suggested by the "fatigue of the city." At all events, it is important to note that the "fatigue of the city" should not be considered apart from "love." Yet, strangely enough, the poem embodies a severe critique of the city, and further investigation is necessary in order to clarify why this critique appears in the form of "love." But this will be the treated in another paper.

• Journal of Korea Water Resources Association
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• v.46 no.12
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• pp.1141-1155
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• 2013

A number of studies have been performed to analyze climate change impacts of water resources system. In this study, a coordinated dam operation is compared with an existing operation strategy for coping with projected future runoff scenarios. GCMs (Global Circulation Models) and the LARS-WG downscaling method was used to project future climate scenarios. The water balance model called abcd was employed to estimate future runoff scenarios. The existing dam operation comes from the national dam construction guideline, which is called the "level-operation method." The alternative coordinated dam operation are constructed as a linear programming using New York City rule for refill and drawdown seasons. The results of annual total inflow in future is projected to decrease to 72.81% for Andong dam basin and 65.65% for Imha dam basin. As a result of applying future runoff scenarios into the dam operation model, the reliability of coordinated dam operation, 62.22%, is higher than the reliability of single dam operation, 46.55%. Especially, the difference gets larger as the reliability is low because of lack of water. Therefore, the coordinated operation in the Andong & Imha dams are identified as more appropriate alternative than the existing single operation to respond to water-level change caused by climate change.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.26-40
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• 2018

As urban regeneration and revitalization projects become increasingly popular in Korea, interests in residential environment, landscape improvement and community activities have risen, resulting in increased interest in community garden, a type of urban agriculture. However, the concept of community garden in Korea is yet to be defined apart from the general concept of urban agriculture. Also, any discussion regarding a practical scheme for community gardens remains nascent. Therefore, in order to define and to understand community gardens, and to draw meaningful implications for the community garden research in Korea, this study conducted a preliminary field survey of four North American cities from where the idea of community gardening originates. A total of 166 community gardens in Seattle, New York, Philadelphia and Vancouver were visited during this survey. Four community gardens from each city were selected for further analysis, with particular emphasis on spatial organization and social functions. The results showed that the community gardens in each city perform a diverse array of functions depending on location, type and societal needs. Community gardens in Seattle and Vancouver, which may be classified as 'uptown,' focused on their roles as fields of 'community participation.' Those in New York and Philadelphia, which are classified as 'downtown,' emphasized their function in 'urban beautification.' This study demonstrates that the community gardens in North America serve their roles as urban amenities and multi-functional public spaces for the entire local population. The implication of the results is that considerations for the social roles the community gardens serve and the spatial elements that allow the space to perform such functions are necessary for the further developments in the community garden research in Korea.

• Journal of Families and Better Life
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• v.34 no.3
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• pp.45-64
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• 2016

In order to understand Korean American immigrants'adjustment to American society, it is important to understand how their life rituals and ethnic identities maintain or change over time and across immigration generations. To achieve this goal, this study examined how Korean Americans who resided in the New York City metropolitan area and New Jersey State performed life rituals and formed ethnic identities. A total of 18 Korean immigrants participated in one-on-one in-depth interviews and the interview data were analyzed with the themes. The results showed that Korean Americans performed life rituals integrating both Korean and American cultural aspects. Many Korean Americans attempted to perform life rituals based on American cultural holidays and procedures. However, a majority of these Koreans also strived to maintain Korean ethnic identities and also practice traditionally Korean life rituals as a way to preserve this ethnic identity. These findings suggest that across time and generation, Korean Americans prefer to maintain their Korean cultural identity, while not shunning the adoption of typical "American" rituals. The way that Korean Americans practice and develop identities differs very little across immigration generation. These findings provide insight on how the Korean government may support foreigners and immigrant families in South Korea and Korean Americans' acculturation processes in the U.S.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1999-2004
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• 2013

Asian Americans experience disproportionate incidence and mortality rates of certain cancers, compared to other racial/ethnic groups. Primary care physicians are a critical source for cancer screening recommendations and play a significant role in increasing cancer screening of their patients. This study assessed primary care physicians' perceptions of cancer risk in Asians and screening recommendation practices. Primary care physicians practicing in New Jersey and New York City (n=100) completed a 30-question survey on medical practice characteristics, Asian patient communication, cancer screening guidelines, and Asian cancer risk. Liver cancer and stomach cancer were perceived as higher cancer risks among Asian Americans than among the general population, and breast and prostate cancer were perceived as lower risks. Physicians are integral public health liaisons who can be both influential and resourceful toward educating Asian Americans about specific cancer awareness and screening information.

• Journal of Information Technology Services
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• v.15 no.1
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• pp.39-66
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• 2016

There is growing evidence that professional work is changing as a result of the application of information technology (IT). However, the impact of information technology on professional work has produced mixed results. Our paper considers the source of these mixed results through a greater analytical attention paid to the nature of professional work. Defined as work involving expertise expressed through abstract and formalized knowledge as well as extensive working knowledge, the professional work logic assumes the greatest autonomy and discretion for workers in collectively controlling work characteristics-division of labor and its permanence, control over education, and control over new entrants and the monitoring and disciplining of existing members. The impact of IT on professional work will be difficult to control and predict without considering the assumptions and tensions within and across the three major types of work logics (Professional, Market and Bureaucratic). Using healthcare as an example, the paper provides various propositions for researching the initiation and effects of ICT design through these three work logics. These propositions illustrate the active role that IS researchers can take in researching an important economic and work-related topic, professional work, and in understanding how ICT affects work-related expertise.