• Korean Institute of Interior Design Journal
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• v.25 no.6
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• pp.139-148
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• 2016

Chronic patients and staffs in healthcare facilities cannot avoid long-term stays indoors. Therefore, they need to get adequate amounts of sunlight to prevent diseases caused by vitamin D deficiency. This is a case study on the advanced daylighting systems installed to healthcare facilities for therapeutic environments as serving natural light therapy and a pleasant atmosphere. This paper shows daylighting devices that overcome the structural limits of architectural design solutions for inducing natural light. This study presents appropriate daylighting technologies to the purpose and types of healthcare facilities by analyzing therapeutic environmental factors. Natural light delivered through daylighting devices help directly patients recover. In addition, it can improve healthcare providers' performance and productivity, and reduce their errors, thereby creating therapeutic environments for patients, indirectly. Excellent color rendering of solar illumination is also a powerful tool for navigation and wayfinding in the buildings, and for aesthetic treatment in dental office. Furthermore, daylighting systems are streamlined and require the least material and space to attract sunlight up to the deeper inside. But because of expensive cost, they have not yet been widespread. Though daylighting devices are typically more expensive than artificial illuminations to install, the running cost savings can compensate for the initial installation cost. With the development of technology in the future, the market price of them is expected to be formed properly.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.2
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• pp.139-146
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• 2002

The third generation mobile communication needs to provide multimedia service with increased data rates. Thus an efficient allocation of radio and network resources is very important. This paper models the 'burst switching' as an efficient radio resource allocation scheme and the performance is compared to the circuit and packet switching. In burst switching, radio resource is allocated to a call for the duration of data bursts rather than an entire session or a single packet as in the case of circuit and packet switching. After a stream of data burst, if a packet does not arrive during timer2 value ($\tau_{2}$), the channel of physical layer is released and the call stays in suspended state. Again if a packet does not arrive for timerl value ($\tau_{1}$) in the suspended state, the upper layer is also released. Thus the two timer values to minimize the sum of access delay and queuing delay need to be determined. In this paper, we focus on the decision of $\tau_{2}$ which minimizes the access and queueing delay with the assumption that traffic arrivals follow Poison process. The simulation, however, is performed with Pareto distribution which well describes the bursty traffic. The computational results show that the delay and the packet loss probability by the burst switching is dramatically reduced compared to the packet switching.

• IE interfaces
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• v.13 no.3
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• pp.471-478
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• 2000

One of the most important problems encountered by parcel transportation firms or LTL (Less-than-truckload) firms is the planning of daily linehaul operations. The transportation firm's goal is to determine the most efficient way to move all freight from its originating terminal to its destination terminal after each shipment is picked up from the shipping dock. The purpose of this study is to design a transportation system and develop an efficient scheduling algorithm for linehaul operations carrying small amount of shipment. This paper presents three approaches for efficient linehaul operations. The first approach examines drivers using the roundtrips which start from a terminal, visit several terminals, and return to the starting terminal. The second approach uses a freight assembly center where drivers take freight for a number of destination terminals which they then swap for freight for their starting terminal. The third approach is similar to the second approach in that it uses a transshipment point like a freight assembly terminal for shipment, but it has several transshipment points since each shipment may have a different transshipment point. In this study, we developed a mathematical formulation and algorithm for each approach. The experimental results using data of a LTL firm show that the third approach is more efficient than the other two. Mileage and overnight stays of the third approach are reduced by 10% and 30%, respectively.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.123-137
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• 1993

In this paper, an integrated approach is proposed to generate gouging-free Cartesian tool paths for machining sculptured surfaces from 3D measurement data. The integrated CAD/CAM system consists of two modules : offset surface module an Carteian tool path module. The offset surface module generates an offset surface of an object from its 3D measurement data, using an offsetting method and a surface fitting method. The offsetting is based on the idea that the envelope of an inversed tool generates an offset surface without self-intersection as the center of the inversed tool moves along on the surface of an object. The surface-fitting is the process of constructing a compact representation to model the surface of an object based on a fairly large number of data points. The resulting offset surtace is a composite Bezier surface without self-intersection. When an appropriate tool-approach direction is selected, the tool path module generates the Cartesian tool paths while the deviation of the tool paths from the surface stays within the user-specified tolerance. The tool path module is a two-step process. The first step adaptively subdivides the offset surface into subpatches until the thickness of each subpatch is small enough to satisfy the user-defined tolerance. The second step generates the Cartesian tool paths by calculating the intersection of the slicing planes and the adaptively subdivided subpatches. This tool path generation approach generates the gouging-free Cartesian CL tool paths, and optimizes the cutter movements by minimizing the number of interpolated points.

• Journal of computational fluids engineering
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• v.9 no.3
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• pp.18-25
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• 2004

Multi plume effects on the base heating have been Investigated with a CFD program. As the flight altitude increases, the plume expansion angle increases regardless of the single or clustered engine. The plume interaction of the clustered engine makes a high temperature thermal shear in the center of four plumes. At low altitude, the high temperature shear flow stays in the center of plumes, but it increases up to engine base with the increasing altitude. At high altitude, the flow from plume to base and the flow from base into outer free stream are supersonic, which transfers the high heat in the center of plumes to the base region. The radiative heat of the clustered engine varies from 220 kW/m² to 469 kW/m² with increasing altitude while those of the single engine are 10 kW/m² and 43.7 kW/m². And the base temperature of the clustered engine varies from 985K to 1223K, and those of the single engine are 483K and 726K. This big radiative heat of clustered engine can be explained by the active high temperature base flow and strong plume interactions.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.8
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• pp.385-393
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• 2008

The best coverage problem is finding a path whose worst distance to the sensor-set is the best among all paths. Instead, if the user stays close to its nearest two sensors, then the stability of the wireless connection may be guaranteed. So we consider the problem of finding a second best coverage path; given the sensor set U, a starting point s and a target point t, find a path whose worst distance to the second closest sensor is minimized. This paper presents an O(n logn) -time algorithm to find such a path. We also give experimental evidence showing that the connection to the sensor-set along a second best coverage path is more stable than that along the best coverage path.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.3.1-3.6
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• 2015

Objectives This study aims to evaluate the size-dependent toxicity of spherical silver nanoparticles (Ag NPs) to an endemic benthic organism, Glyptotendipes tokunagai. Methods Ag nanoparticles of three nominal sizes (50, 100, and 150 nm) capped with polyvinyl pyrrolidone (PVP-Ag NPs) were used. Their physicochemical properties, acute toxicity (48 hours), and bioaccumulation were measured using third instar larvae of G. tokunagai. Results The aggregation and dissolution of PVP-Ag NPs increased with exposure time and concentration, respectively, particularly for 50 nm PVP-Ag NPs. However, the dissolved concentration of Ag ions was not significant compared with the median lethal concentration value for $AgNO_3$ (3.51 mg/L). The acute toxicity of PVP-Ag NPs was highest for the smallest particles (50 nm), whereas bioaccumulation was greatest for the largest particles (150 nm). However, larger PVP-Ag NPs were absorbed and excreted rapidly, resulting in shorter stays in G. tokunagai than the smaller ones. Conclusions The size of PVP-Ag NPs significantly affects their acute toxicity to G. tokunagai. In particular, smaller PVP-Ag NPs have a higher solubility and stay longer in the body of G. tokunagai, resulting in higher toxicity than larger PVP-Ag NPs.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.723-731
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• 2016

Background: Cancer is a major public health problem in many parts of the world. Gastrointestinal (GI) cancers are responsible for 20% of all cancer-related deaths. In Turkey, stomach cancers account for 8.9%, colon cancer for 6.9%, and pancreatic cancer for 5.9%. This study examined the anxiety-depression levels and the quality of life of patients with GI cancer. Materials and Methods: This descriptive study was carried out on 335 adult patients who had gastrointestinal cancer and who were hospitalized in medical oncology clinics. Data were collected by using hospital anxiety and depression scale, EORTC QLQ C-30 and a patient information form. Results: Patients who were male and secondary school graduates/graduates/postgraduates experienced more functional difficulties. Patients with poor economic status experienced more symptoms. Patient general wellbeing decreased with increase disease duration. The level of functional difficulties decreased with an increasing number of hospital stays. Anxiety scores increased with decreasing age. Both anxiety and depression scores increased with increasing disease duration. Patients who were female, single/widowed/divorced, and literate/elementary school graduates had higher anxiety and depression scores. Life quality decreased with increasing anxiety and depression. Conclusions: Patients should be supported to prevent anxiety and depression, and should be followed up with this in mind.

• Journal of Korean Physical Therapy Science
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• v.9 no.3
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• pp.141-150
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• 2002

Most of physical therapists has thought be exposed themselves to risk of hospital infection but it is reported that have been low concern about infection management. Above like this haven t done systematical education on hospital infection, also physical therapist's information management of infection disease is found very low. It is lack of driving information about disease condition of the patients. Physical therapists has thought their working room may be polluted a lots of micro-organism(%). The control situation of infection waste articles, only 53% responded that the controller has managed very intensive so we can feel to need more intensive It's reported that air culture investigation of physical therapy room has never initiated. To wash the hand, before, after treatment of the patients of physical therapist, is very low frequency. And 73% have responded that the time to wash the hand stays 15-45 second. It is examined that 70% physical therapy room is equipped with washing system, a response of 58% disinfects physical therapy room 1-2times per one month. 36% responded disinfection of treatment modality have done everyday, 25% responded have never done. The location physical therapy room is above one floor - 65%. A response of 57% is ventilation system sufficiency, it is considered that physical therapists needs more efforts on management of hospital infection.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.11a
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• pp.137-140
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• 1993

Electrical properties and thermal annealing effects of $C_{22}$-quinolium(TCNQ) Langmuir-Blodgett(LB) films were studied. Typical current-voltage(I-V) characteristics along the perpendicular direction chow an anomalous behavior of breakdown near the electric-field strength of $10^{6}$V/cm. To see the thermal influence of the specimen, current was measured as a function of temperature(20∼$180^{\circ}C$). It shows that the current increases about 4 orders of magnitude near 60∼$70^{\circ}C$ and remains constant far a while up to ∼$150^{\circ}C$ and then suddenly drops. Such increase of current near 60∼$70^{\circ}C$ seems tn be related to a softness of alkyl chains. Besides the electrical measurements, UV/visible absorption(300∼800 nm) of the thermally annealed sample was measured to see the internal-structure change. It is found that there are four characteristic peaks. At 494 nm, the optical absorption of the thermally annealed specimen at $60^{\circ}C$ starts increase and stays almost constant upto∼ $140^{\circ}C$. And eventually it disappears above $180^{\circ}C$. After heat treatment of the specimen up to $150^{\circ}C$, Uv/visible absorption was measured while cooling.