• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.77-82
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• 2010

Our study aims to understand the flow of liquid in an open-top rectangular microchannel that can be used in micro total analysis systems ($\mu$-TAS) because it has advantages in terms of light transmission and energy efficiency. We measured the liquid velocity using particle tracking technique and conducted a simulation with computational fluid dynamics by altering the area of channel cross section and channel length for the capillary-driven flow in the open-top rectangular microchannel. When liquid water drops to an entrance of the fabricated microchannel with a height of 20 μm and a width of 20 ${\mu}m$, it flows along the microchannel by only capillary force. In the wetting behavior of the liquid, important parameters of this flow are channel size, contact angle and liquid properties such as surface tension and viscosity, which are used to control the flow of liquid in the microchannel.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.336-341
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• 2018

In general, the synthesis of poly(3-hexylthiophene)(P3HT)-based block copolymers requires at least a 4-5 step process. To control the molecular weight, molecular weight distribution, and block ratio, the reaction conversion and time should be monitored. In addition, the reaction scale usually limited to several mg to g was difficult to increase due to the limitations of living radical polymerizations. In this study, we synthesized P3HT-b-poly(4-vinylprydine) (P3HT-b-P4VP) with a final product quantity of > 19 g via a 2-step synthetic method with an anionic polymerization. In this method, the molecular weight and molecular weight distribution of P3HT-b-P4VP can be well controlled without monitoring the reaction conversion. We also studied physical properties of P3HT-b-P4VP depending on different solvent systems, which were investigated by UV-vis spectroscopy, atomic force microscopy, and ultraviolet photoelectron spectroscopy.

• Journal of Animal Science and Technology
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• v.50 no.6
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• pp.839-848
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• 2008

This study was conducted to determine the effect of mugwort powder on carcass characteristics, proximate composition, cholesterol contents, and meat qualities in growing-finishing gilt and barrow(LY×D). Totally 80 pigs (40 gilts and 40 barrows, approximately 50kg each) with 10 pigs per treatment were randomly alloted. The diet group was prepared as 0(C), 0.5(T1), 1.0(T2), and 1.5%(T3) mugwort powder in basal diet, respectively. They were fed experimental diets for 90 days before slaughtered. Carcass weight was increased by dietary mugwort powder(p<0.05), whereas changes in back fat thickness and meat grade were unaffected by dietary supplements. Meat moisture, fat, ash, and cholesterol were not differ significantly in the samples, however, protein in T2 and T3 were significantly higher than the control (p<0.05). Meat pH48, water holding capacity, and cooking loss were not differ significantly in the samples (p>0.05), and shear force of fresh meat and fat were not differ significantly in the samples(p>0.05). Lightness(L*) of meat was increased but that of fat was decreased by dietary mugwort powder, whereas changes in redness(a*) and yellowness(b*) were unaffected by dietary supplements.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.166-174
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• 2000

Anchovy, EngrauEis japonica scoop nets are used in the coastal of Southern and Cheju of Korea. Especially in the Cheju, the fishing gear of scoop nets consists of upper boom, lower boom, pressing stick and bag net. They are operated by fishing boats of 6 to 10 ton class and 8 persons on board. The booms are controlled by side drum, and the net and pressing stick are hauled by only human power in operating. Therefore this fishery needs to large labor and heavy human power and has much risk. Three kinds of hydraulic winding device which controls two booms was designed and manufactured to reduce heavy labor force of scoop nets, and trial in the sea was carried out to test their performances using the commercial fishing boats of 6 ton class. The proper capacity of hydraulic pump and motor were determined by model test of boom 1/5 scale. The results obtained are as follows, 1. Tension of boom which is being drawn was the strongest and 187.5kgf when the boom's end is in the depth of 4m under the water. 2. The hydraulic motor of the fittest kind of winder has the least leakage per time than the other kinds. 3. In the best type of several winder devices, when the pressure difference was fixed $130kg/^2$ for the safe fishery, the winding velocity of boom line was 2m/sec, is faster 0.48/sec than traditional fishing method and this winder can catch the anchovy of 1.6 tonnage. 4. As a result, the crew were decreased from 8 to 6 and the problem of heavy human power and risk on fishing operation were solved by using the this winder.

• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.3-26
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• 1985

The object of this study was to investigate the effects on physical and mechanical properties of wood particle and sawdust board combined with wire net. Conventional forming, press-lam, and veneer comply boards combining one to four wire net sheets were made from wood particle and sawdust with different spacings (8, 10, 12, and 18 Mok) and different wire diameters (0.35, 0.50, and 0.80mm) composing wire net. They were compared and analyzed statistically with specific gravity, thickness swelling, length swelling, bending properties (modulus of rupture, modulus of elasticity, work to proportional limit, and total work), internal bonding strength, and screw holding strength between wood particle and sawdust boards. The results obtained at this study as cording to the discussions might be concluded as follows; 1. In specific gravity, both particle and sawdust boards by press-lam method were higher than by conventional forming and veneer comply method, and the boards containing more wire net sheets also showed higher value. But the wire net spacings(Mok) had no influence on specific gravity. In general, particle board showed higher specific gravity than sawdust board. Veneer comply board showed lowest specific gravity values. 2. Both particle and sawdust boards by press-lam method was slightly lower than by conventional forming and veneer comply method in thickness swelling. The sawdust board containing 8, 12. and 18 Mok wire net showed lower thickness swelling than the corresponding particle board, but both sawdust and particle boards containing the T8 and 10 Mok wire net showed higher and similar thickness swelling. 3. Both particle and sawdust boards containing wire net showed no difference in MOR and MOE of bending. Comply board was the highest and particle board showed slightly higher than sawdust board in MOR and MOE values. 4. In work to proportional limit and total work in bending, both particle and sawdust boards containing thicker wire diameter and more wire net sheets showed higher value. From these facts, it is conceivable that boards with thicker wire diameter and more wire net sheets show increasing resistance against external force. But there was no significant difference between particle and sawdust borads. 5. In resistance against delamination (internal bonding strength), both sawdust and particle boards containing wire net showed lower value than control, and also showed decreasing tendency with more number of wire net sheet composed. Particle board showed higher resistance against delamination than sawdust board. 6. In screw holding strength, sawdust board containing thicker wire diameter and more wire net sheets showed higher value, but particle board by press-lam method was higher than by conventional forming and veneer comply method. Screw holding strength of particle board was higher than that of sawdust board.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.638-647
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• 2018

We have to prepare for the existing threats from North Korea and potential threats in the future. It is important to utilize our resources as effectively as possible to build military power that brings victory in a war. Based on a sustainable required operational capability, weapons systems at the acquisition stage need to maintain a combat-readiness posture and ensure operational sustainability. To achieve this, establishment of procedures that develop elements of depot maintenance at the beginning, which enables economical and effective depot maintenance during that stage, is essential. First, the requirement paper needs to develop the concept of the depot maintenance requirement through the pre-study outlined by this paper. Second, at the system development stage, a Development Plan of Depot Maintenance draft should be proposed. This is the initial paper that can develop the elements of depot maintenance, and it should be verified by a field test. Third, each force's logistics command should write a Depot Maintenance Direction draft and a Mid-term Requirement of Elements of Depot Maintenance draft with the proven Development Plan of Depot Maintenance draft. Also, the verified paper needs to be realized and renewed by the time the Requirement of Elements of Depot Maintenance draft is completed. In conclusion, the procedures explained above will contribute to build an economical and effective military power in a reality faced with a resource shortage and threats from the enemy.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.348-351
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• 2006

Bipolar plate, which forms about 50% of the stack cost, is an important core part with polymer electrolyte membrane in PEMFC. Bipolar plates have been commonly fabricated from graphite meterial having high electrical conductivity and corrosion resistance. Lately, many researchers have concentrated their efforts on the development of metallic bipolar plate and stainless steel has been considered as a potential material for metallic bipolar plate because of its high strength, chemical stability, low gas permeability and applicability to mass production. However, it has been reported that its inadequate corrosion behavior under PEMFC environment lead to a deterioration of membrane by dissolved metal ions and an increase in contact resistance by the growth of passive film therefore, its corrosion resistance as well as contact resistance must be improved for bipolar plate application. In this work, several types of coating were applied to 316L and their electrical conductivity and corrosion resistance were evaluated In the simulated PEMFC environment. Application of coating gave rise to low interfacial contact resistances below $19m{\Omega}cm^2$ under the compress force of $150N/cm^2$. It also made the corrosion potential to shift in the posit ive direct ion by 0.3V or above and decreased the corrosion current from ca. $9{\mu}A/cm^2$ to ca. $0.5{\mu}A/cm^2$ in the mixed solution of $0.1N\;N_2SO_4$ and 2ppm HF A coat ing layer under potentiostatic control of 0.6V and $0.75V_{SCE}$ for 500 hours or longer showed some instabilities, however, no significant change in coat Ing layer were observed from Impedance data. In addition, the corrosion current maintained less than $1{\mu}A/cm^2$ for most of time for potentiostatic tests. It indicates that high electrical conductivity and corrosion resistance can be obtained by application of coatings in the present work.

• Archives of design research
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• v.16 no.2
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• pp.415-424
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• 2003

People store information not only in their Drain but also material things. Norman called it knowledge in the world. The general way to store the information is to paste labels. 4 burner gas range force user to make conceptual model between burner and switch to see labels. but those are cognitive stress. Norman suggested spatial analogies for natural mapping between display and control. However the way of his methods in spatial analogies was not compatible with kitchen atmosphere. To solve those problems 1 suggested color coding . This study hypothesized that the mapping between burner and switch is realized by color coding. To testy the hypothesis 1 compared A group using general gas range with B group using color coded gas range. The result showed difference between A and B in accuracy ( F (1, 38) = 17.892, p < 0.01) and response time ( F (1, 38) = 6.726 p < 0.05). The result of this test is to certify that color coding affect peoples by presenting the difference accuracy and response time. As result this study presents that color coding can be compatible the product having importance to certify in the design process.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.598-617
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• 2020

In many enterprises, the extent and the frequency of damages incurred due to the unethical behavior of the members of the organization have not reduced, but rather the magnitude and frequency of damages have been increasing. Research at an organizational level is necessary at this point in time, to investigate the contributing variables that cause this unethical behavior, the measures to manage them, and the control variables that can reduce unethical pro-organizational behavior. Therefore, this study seeks to explore perceived organizational support and psychological entitlement as leading factors of unethical pro-organizational behavior, based on the theory of social exchange, and to examine the reaction mechanism between these variables. This is particularly because a large number of the current labor force belongs to the millennial generation (born after 1978) or Generation Y, and their sense of psychological entitlement has been problematic in their organization. The effect of perceived organizational support on unethical pro-organizational behavior and the effect of psychological entitlement on unethical pro-organizational behavior were examined through a review of existing literature, and an empirical analysis was conducted to investigate the moderating effects of psychological entitlement on perceived organizational support and unethical pro-organizational behavior. A regression analysis was conducted based on the valid data of 185 members of an organization who belong to the millennial generation, and the analysis results showed that a sense of psychological entitlement had a moderating effect between perceived organizational support and unethical pro-organizational behavior. Based on these findings, this paper proposes theoretical and practical implications for unethical pro-organizational behavior and psychological entitlement, and hopes to contribute to expanding research in this area.

• Health Policy and Management
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• v.9 no.1
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• pp.30-71
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• 1999

There has been a dramatic increase in public awareness regarding dementia during recent years. However, dementia remains a family affair and patients do not receive adequate care in Korea. This study aims to assist patients and their caregivers by establishing Home and Community based Long-Term Care in a city. The data collected for analysis include five main categories: dementia prevalence, limitations of daily activities of patients, burden of caregivers, the services that patient's family want to utilize, the resources that handle dementia in the community. Major findings can be summarized as follows: 1)The prevalence rate of dementia for elderly people is 13.1 per 100 persons. Alzheimer's disease amount to 38.9% of dementia patients and vascular dementia account for 36.7% of them 2)Eight out of ten patients have mild dementia. Almost all patients have normal ADL. IADL, however, shows different picture. In every items of IADL, about 60% of patients reveals some limitations. 3)The proportion of patients who had medical diagnosis is as low as 20%. Families of patients think dementia as normal aging process and medical doctors in the community do not give special concern to dementia patients. 4)Caregivers does not have proper social support. They suffer from long care time, experience large obstacles in respect of health, daily living, and social activity. 5)Health center and Community welfare center have launched some programs-consultation, home-visiting nursing, day care center, voluntary force mobilization and so on-for dementia patients. But they do not perform expected roles and functions because of lack of skilled personnels and inadequate coordination of relevant organizations for dementia care. 6)Families of dementia patients prefer home helper and home-visiting nurse to hospitalization. For the future, however, demand for institution-based long-term services will increase. We develope community dementia care model based on above findings as follows: 1)Health center execute community cardiovascular control program for the prevention of vascular dementia. 2)Refer to epidemiologic characteristics of patients and preference of family, the most urgent task for dementia care in this city is to expand and organize Home and Community based Long-Term Care. 3)For the continuous and comprehensive care, care plan for a patient must be prepared. Case management team should be builded to prepare this plan and coordinate relevant resources. 4)Special long-term care unit for dementia will be needed in a near future. This unit should have multiple functions, such as day-care center, short stay facility, training center for relevant personnels, besides long-term nursing home considering effective care of dementia and efficient operation of the facility. 5)Voluntary workers deserve their due efforts. Incentive mechanisms must be developed to activate voluntary activities.