• KIEAE Journal
• /
• v.13 no.3
• /
• pp.27-32
• /
• 2013

Infiltration is air flow that occurs through cracks in buildings. According to level and kind of infiltration, the cooling load and heating load in buildings may increase. In this study I conducted field measurements to evaluate air tightness in 27 new apartment units. Field measurements for new apartments was the focus. For the de-pressurization method, the equipment utilized to gauge airtightness included KNS-5000C and KNS-4000 which were installed on the window in order to measure indoor air leakage. The results are summarized as follows. The average ACH50 of a $59m^2$ APT was 3.98, 3.82 for a $84m^2$ APT, and 2.73 for a $114m^2$ APT. The total average ACH50 of 27units was 3.51.

• Smart Structures and Systems
• /
• v.3 no.3
• /
• pp.245-261
• /
• 2007

Nonlinear time-domain system identification (SI) algorithm is proposed to assess damage in a shear building by synchronously estimating time-varying stiffness and damping parameters using measured acceleration data. Mass properties have been assumed as the a priori known information. Viscous damping was utilized for the current research. To chase possible nonlinear dynamic behavior under severe vibration, an incremental governing equation of vibrational motion has been utilized. Stiffness and damping parameters are estimated at each time step by minimizing the response error between measured and computed acceleration increments at the measured degrees-of-freedom. To solve a nonlinear constrained optimization problem for optimal structural parameters, sensitivities of acceleration increment were formulated with respect to stiffness and damping parameters, respectively. Incremental state vectors of vibrational motion were computed numerically by Newmark-${\beta}$ method. No model is pre-defined in the proposed algorithm for recovering the nonlinear response. A time-window scheme together with Monte Carlo iterations was utilized to estimate parameters with noise polluted sparse measured acceleration. A moving average scheme was applied to estimate the time-varying trend of structural parameters in all the examples. To examine the proposed SI algorithm, simulation studies were carried out intensively with sample shear buildings under earthquake excitations. In addition, the algorithm was applied to assess damage with laboratory test data obtained from free vibration on a three-story shear building model.

• Journal of Korea Multimedia Society
• /
• v.24 no.1
• /
• pp.30-39
• /
• 2021

Research in the field of health lighting has continued to advance to reproduce the color temperature of natural light which periodically changes. However, most of this research could only reproduce a uniform circadian color temperature of natural light, therefore failing to realize the characteristics of the circadian cycle of color temperature difference by latitude and longitude. To reproduce the color temperature of natural light on which the characteristics of a region are reflected, the collection technology of real-time characteristics of natural light is needed. If the color temperatures which are not within a periodical pattern due to climate changes, etc., are measured, it will be difficult to judge the occurrence (presence) of the anomalies and to reproduce the circadian cycle of the color temperature of natural light. Therefore, this study proposes an algorithm for judging the anomalies in real time based on the sliding window to reproduce the color temperature of natural light. First, the natural light characteristics DB collected through the on-site measurement were analyzed, the differential values at a one-minute interval were calculated and examined, and then representative color temperature circadian patterns by solar terms were drawn. The anomalies were then detected by the application of the sliding window that calculated the deviation of the color temperature for the measured color temperature data set, which was collected through RGB sensors, while moving along the time sequence. In addition, the presence of anomalies was verified through the comparison study between the detection results and the representative circadian cycle of the color temperature by solar term. The judgment method for the anomalies from the measured color temperature of natural light was proposed for the first time, confirming that the proposed method was capable of detecting the anomalies with an average accuracy of 94.6%.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1993.10a
• /
• pp.32-37
• /
• 1993

This study investigates the relationship between size, illumination ,and display of show window. The average width, heigh, and depth of show windows in Taegu area were 341.3, 233.4, and 125.8cm, respectively. As light source, halogen lamp was most frequently used, followed by fluorescent lamp and incandescence lamp. In the actual illumination, however, a combined use of more than 2 light sources was common. Further, a local illumination method, e.g., spot light, was generally adopted. The thought of employers and employees in fashion shops about display and illumination was examined aw well. On the whole, the necessity and importance of display were well recognized but the fact that the illumination should be hamonized with other factors such as color and arrangement of goods was underestimated.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.1
• /
• pp.224-241
• /
• 2015

Multiview plus depth (MVD) videos are widely used in free-viewpoint TV systems. The best-known technique to determine depth information is based on stereo vision. In this paper, we propose a novel local stereo matching algorithm which is radiometric invariant. The key idea is to use a combined matching cost of intensity and gradient based similarity measure. In addition, we realize an adaptive cost aggregation scheme by constructing an adaptive support window for each pixel, which can solve the boundary and low texture problems. In the disparity refinement process, we propose a four-step post-processing technique to handle outliers and occlusions. Moreover, we conduct stereo reconstruction tests to verify the performance of the algorithm more intuitively. Experimental results show that the proposed method is effective and robust against local radiometric distortion. It has an average error of 5.93% on the Middlebury benchmark and is compatible to the state-of-art local methods.

• International Commerce and Information Review
• /
• v.16 no.4
• /
• pp.55-75
• /
• 2014

Non-parametric method such as technology efficiency, DEA/Window model and Malmquist Productivity Index (MPI) are used to measure efficiency and productivity of ICT (Information and Communication Technology) manufacturing industry and service industry over the period 2007-2011. The results of this paper indicate following: (1) Technology efficiency of the ICT manufacturing industry were found as the range of 0.34 and 0.39 over the sample period. Technology efficiency of the ICT service industry were found as the range of 0.16 and 0.20 over the sample period. (2) The geometric average of the Malmquist TFP indexes on ICT manufacturing industry indicated the productivity improvement an average of 8.3 percent. The geometric average of the Malmquist TFP indexes on ICT service industry indicated the productivity improvement an average of 1.6 percent. (3) TIER analysis result on ICT manufacturing industry showed that optimal bench marking made by storage devices${\rightarrow}$wireless communication equipment${\rightarrow}$broadcasting equipment${\rightarrow}$radio, recording and playback devices${\rightarrow}$computers, printers, video and audio-visual equipment path. TIER analysis result on ICT service industry indicated that optimal bench marking made by computers and packaged software${\rightarrow}$wired communication${\rightarrow}$communication, information, detection equipment${\rightarrow}$consulting and construction for computer systems integration${\rightarrow}$industrial machinery and equipment rental${\rightarrow}$telecommunications reseller${\rightarrow}$system software development and delivery${\rightarrow}$hosting path.

• Journal of information and communication convergence engineering
• /
• v.21 no.1
• /
• pp.90-97
• /
• 2023

Digital holographic microscopy (DHM) is a three-dimensional (3D) imaging technique that uses the phase information of coherent light. In the reconstruction process of DHM, a narrow region around the positive or negative sideband from the Fourier domain is windowed to avoid noise due to the DC spectrum of the hologram spectrum. However, the limited size of the window also degrades the high-frequency information of the 3D object profile. Although a large window can have more detailed information of the 3D object shape, the noise is increased. To solve this trade-off, we propose phase difference averaging (PDA). The proposed method yields high-frequency information of the specimen while reducing the DC noise. In this paper, we explain the reconstruction algorithm for this method and compare it to various conventional filtering methods including Gaussian, Wiener, average, median, and bilateral filtering methods.

• KIEAE Journal
• /
• v.6 no.2
• /
• pp.35-42
• /
• 2006

This study is to investigate the possibility of a quantitative analysis on sunshine right in apartment houses with a new evaluation index of shading area ratio(SAR) which represents seasonal average value of shaded portion of a window during definite period. SAR values of each apartment houses in a prototype building was calculated depending on apartment building arrangement types and orientations. Since the new method proposed in this research is able to measure the sunshine possibility of the each house in detail, which is more precise and descriptive than the existing method of sunshine judgment standard based on the sunshine hours only at winter solstice, it can be appropriately utilized as a highly qualified sunshine right judgment measures in apartment buildings.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.2
• /
• pp.191-195
• /
• 2008

This paper proposes a technique for improving IEEE 802.11e EDCA's performance by dynamically adjusting each class's contention window size based on each class's traffic amount. For providing differentiated service differently from 802.11, 802.11e EDCA maintains four classes each of which specifies different static minimum and maximum contention window sizes. Since the initial window sites significantly affect the 802.11e performance, several window adjustment schemes have been proposed. One of the schemes known as CWminAS (CWmin Adaptation Scheme) dynamically and synchronously determines the four windows' site based on the periodically measured collision rate. This method, however, can lower the send probability of high priority classes since it can't differentiate their collisions from those of low priority classes, leading to the channel underutilization. For solving this problem, we propose ACATICT(Adaptive Contention-window Adjustment Technique based on Individual Class Traffic) algorithm which adapts each class window size based on each individual collision rate rather than one average collision rate. Our simulation experiments show that ACATICT achieves better utilization by around 10% at maximum.

• Journal of Chest Surgery
• /
• v.40 no.11
• /
• pp.765-769
• /
• 2007

Background: The curative treatment of choice for empyema is decortication of the pleura. The risks of this treatment however are increased for the patient with reduced pulmonary function, complicated calcification or septic shock. In the past, open window thoracostomy was a final stage treatment for chronic empyema. Relatively safe treatment of empyema could be achieved in difficult cases with a closure of the open window after open drainage and use of a myocutaneous flap (one stage or staged). Material and Method: A retrospective study of the cause, progression and final outcome of empyema patients who received open window thoracostomy was performed. 21 patients were followed from 1995 to 2004 in the department of Thoracic and Cardiovascular Surgery in the College of Medicine, Pusan National University. Result: The average age of the patients was $57.5{\pm}15.5$ years (range $25{\sim}78$ years), of whom 16 (76.2%) were men and five (23.8%) were women. Pulmonary function test results showed an average FEV1 of $1.58{\pm}0.49 L$. The type of empyema was tuberculous empyema in 13 cases (61.9%), aspergillosis in three cases (14.3%), parapneumonic empyema in three cases (14.3%) and post-resectional empyema in two cases (10%). Bronchopulmonary fistula was seen in 14 cases. Eight cases were complicated by severe calcification of the pleura. For the four cases of bronchopulmonary fistula, the patients' serratus anterior muscle was covered in their first operation. The average number of ribs resected was $4{\pm}1$. Closure of the open window thoracostomy was performed in 12 cases. The average time to closure after open drainage was $10.22{\pm}3.11$ months and the average defect of the empyemal cavity before the final operation was $330{\pm}110 cc$. Among the 12 cases, there were two cases of spontaneous closure. In two cases closure was only achieved by using the reserved skin fold during the first surgery. Of the remaining eight cases, in seven we used the myocutaneous flap (four cases of lattisimus dorsi muscle and three cases of pectoralis major muscle), and in one case we used soft tissue. As regards complications of the closure, tissue necrosis occurred in one case, which led to failed closure, and there was one case of abdominal hernia in the rectus abdominis muscle flap. One patient died within 30 days of the surgery and one patient died of metastatic cancer. Conclusion: A staged operation with a final closure using open window thoracostomy, which consists of open drainage, transposition of the muscle and a myocutaneous flap, can be a safe and effective option for the chronic empyema patient who is difficult to cure with traditional surgical methods.