• Journal of the Korean Arthroscopy Society
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• v.2 no.2
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• pp.107-113
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• 1998

This study is retrospective analysis of 31 patients treated by arthroscopically assisted ACL reconstruction, from September 1995 to September 1996. ACL reconstructions using autogenous bone patellar tendon bone (B-PT-B) were done in 18 patients, and using hamstring tendon were done in 13 patients. We used four-stranded hamstring tendon grafts and fixed the grafts using Endobutton and screw. The mean postoperative Lysholm knee score was 87.2 points in B-PT-B. group, and 89.0 points in hamstring tendon group. There were no clinically significant results between two groups in Telos test, quadriceps atrophy, Lachman test, anterior drawer test and pivot shift test, but the incidences of anterior knee pain were lower in hamstring group. Four-stranded hamstring tendon graft showed enough stability and good functional outcome similar to that of patellar tendon graft, and had an advantage of quicker return of quadriceps function and less donor site morbidity.

• Water for future
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• v.22 no.1
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• pp.117-125
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• 1989

This study deals with the performance of an acivated sludge system which is modified by the researcher to function without any additional chemical or internal recyle in removing organics, nitrogen, and phosphorus from synthetic wastewater. To improve the nutrient removal efficiency, the researcher utilized the anoxic, anaerobic, and aerobic reactor sequences with a single sludge return, whiched to nitrification/denitrification and phosphorus release/overplus accumulation. A bench scale system was operated with a view to investigating the reaction characteristics of each reactor, and to measuring the biological kinetic coefficients(Y, $K_d$, k, $K_s$) for theremoval of COD in relation to the mean cell residence time at five different MLSS concentrations, 5000, 4200, 3300, 2600, and 1900 mg/l. The results of the research showed that organic substance and nutrient were removed simultaneously by this modified activated sludge process. And the process kad 66%-99% ortho-p removal efficiency.

• Broadcasting and Media Magazine
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• v.11 no.1
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• pp.68-77
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• 2006

The Cognitive Radio (CR) technology is a promising solution for exploiting the limited spectrum resources and providing flexibility of spectrum usage. Future interactive broadcasting service can be realized by utilizing CR concept, since the up-link return channel can be found by the spectrum sensing method, which is core functional block of the CR system. In this paper, the spectrum sensing technologies of CR system is presented. First the system architecture of the CR with spectrum sensing block is presented. The suggested spectrum sensing technique consists of the coarse and the fine spectrum sensing. The coarse spectrum sensing technique adopted the wavelet transform to provide the multi-resolution sensing feature - Multi-Resolution Spectrum Sensing (MRSS). The fine spectrum sensing technique uses the beneficial properties of the autocorrelation function Analog Auto-Correlation (AAC). The simulation results for the proposed sensing technologies are presented for various incumbent signals.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.3
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• pp.224-229
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• 2009

Partial safety factors(PSFs) for Level I reliability based design of caisson type quay walls were calculated. First order reliability method(FORM) based PSFs are the functions of sensitivities of limit state function with respect to design random variables, target reliability index, characteristic values and first moment of random variables. Modified PSFs for water level and resilient water level are newly defined to keep consistency with the current design code. In the numerical example, PSFs were calculated by using a target reliability index. Seismic coefficient is defined to show extreme distribution. It was found that PSFs for seismic coefficient becomes smaller as the return period for design seismic coefficient grows longer.

• Journal of Energy Engineering
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• v.10 no.3
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• pp.214-222
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• 2001

The purpose of this research it to develop gas-air rotary heat exchanger using heat pipe and the performances were examined by way of the theoretical analysis and the experiment. Centrifugal force to return the working fluid in heat pipe elements with different radius was evaluated as a function of the revolution speed and inclination angle, and a rotary heat exchanger with 60 heat pipes in 3 rows was designed and manufactured. The inclination angle of a heat pipe relative to the revolving axis was designed to be 2$^{\circ}$and water was used as a working fluid. Experimental result showed the heat exchange rate was enhanced by 16% with compared to the calculated value.

• Korea Journal of Hospital Management
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• v.22 no.2
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• pp.1-16
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• 2017

1) Purpose: The goal of this study is to examine the association between independent external financial audits and uncompensated care. Not-for-profit hospitals are required to provide uncompensated care in return for tax exemption. These tax exemption benefits are applied to all activities that contribute to the enhancement of uncompensated care. However, some researchers argue not-for-profit hospitals do not provide uncompensated care as expected by their tax exemption. Thus, this paper examines whether independent external financial audits can help the not-for-profit hospitals to function as designed and ultimately for meeting the objectives of the not-for-profit organization, which are the clearest examples of charitable activities performed by not-for-profit hospitals. 2) Methodology: Panel data analysis was utilized with fixed effect using California hospital financial data from 2002 to 2011. 3) Findings: We found that hospitals receiving independent external financial audits provide more uncompensated care than their counterparts which do not receive audits. 4) Practical Implications: Not-for-profit hospitals provide uncompensated care to people in welfare blind spots. Therefore, they fulfill what governments cannot afford, and play a social role as a ʻnonprofitʼ organization with independent external financial audits.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.193-201
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• 2014

In cognitive radio networks, the packet transmissions of the secondary users (SUs) can be interrupted randomly by the primary users (PUs). That is to say, the PU packets have preemptive priority over the SU packets. In order to enhance the quality of service (QoS) for the SUs, we propose a spectrum access strategy with an ${\alpha}$-Retry policy. A buffer is deployed for the SU packets. An interrupted SU packet will return to the buffer with probability ${\alpha}$ for later retrial, or leave the system with probability (1-${\alpha}$). For mathematical analysis, we build a preemptive priority queue and model the spectrum access strategy with an ${\alpha}$-Retry policy as a two-dimensional discrete-time Markov chain (DTMC).We give the transition probability matrix of the Markov chain and obtain the steady-state distribution. Accordingly, we derive the formulas for the blocked rate, the forced dropping rate, the throughput and the average delay of the SU packets. With numerical results, we show the influence of the retrial probability for the strategy proposed in this paper on different performance measures. Finally, based on the trade-off between different performance measures, we construct a cost function and optimize the retrial probabilities with respect to different system parameters by employing an iterative algorithm.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.33-40
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• 2020

The main aim of the study is to test a house pricing model by combining hedonic and asset-based pricing models. An understanding of the relationship between house pricing and its return (the rental income) helps to establish houses as a significant asset class. The model tested the relationship between house pricing (dependent variable) and the house attributes (independent variables) derived from Freeman's framework of housing attributes. This study uses a large data-set of 1,899 sample of new, high-end houses purchased between 2016 and 2019 collected from the national capital region of India (Delhi-NCR). The algorithm was built in R-Script, and stepwise multiple linear regression was used to analyze the model. The analysis of the model proves that the three significant variables, namely, carpet area, pay-off, and annual maintenance charges explain the price function. Further, the model is statistically fit. The major contribution of the study is to understand the key factors and their influence on the house pricing. The model will be helpful in risk assessment in the housing investment and enhance the chances of investment. Policy-makers can use information about the underlying valuation drivers of the house prices to stabilize the market and also in framing the tax policies.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.204-214
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• 2010

A manufacturing/remanufacturing system is investigated with the consideration of required minimum quality of end-of-used products. A constant demand is satisfied by remanufacturing end-of-used products and manufacturing raw materials outsourced from outside. It is assumed in this system that the buyback price and remanufacturing cost are related to the different quality level of end-of-used products. For remanufacturing, only the used products that satisfy a required minimum quality level will be recycled. Thus, the returning rate is a function of the required minimum quality level. Functions of returning rate, buyback price and remanufacturing cost, which are closely connected to the quality level of end-of-used products, are investigated here. Treating the required minimum quality level of end-of-used products, the length of a cycle, the number of manufacturing lots and remanufacturing lots in a cycle as decision variables, the mathematical models with the objective of minimizing the average total cost are constructed. Through construction of a solution process based on Tabu Search algorithm and calculating examples, the validity of the models is illustrated.

• Earthquakes and Structures
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• v.6 no.5
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• pp.561-580
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• 2014

After strong earthquakes conventional frames used worldwide in multi - story steel buildings (e.g. moment resisting frames) are not well positioned according to reparability. Two innovative systems for seismic resistant steel frames incorporated with dissipative fuses were developed within the European Research Program "FUSEIS" (Vayas et al. 2013). The first, FUSEIS1, resembles a vertical Vierendeel beam and is composed of two closely spaced strong columns rigidly connected to multiple beams. In the second system, FUSEIS2, a discontinuity is introduced in the composite beams of a moment resisting frame and the dissipative devices are steel plates connecting the two parts. The FUSEIS system is able to dissipate energy by means of inelastic deformations in the fuses and combines ductility and architectural transparency with stiffness. In case of strong earthquakes damage concentrates only in the fuses which behave as self-centering systems able to return the structure to its initial undeformed shape. Repair work after such an event is limited only to replacing the fuses. Experimental and numerical investigations were performed to study the response of the fuses system. Code relevant design rules for the seismic design of frames with dissipative FUSEIS and practical recommendations on the selection of the appropriate fuses as a function of the most important parameters and member verifications have been formulated and are included in a Design Guide. This article presents the design and performance of building frames with FUSEIS 1-1 based on models calibrated on the experimental results.