• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.5
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• pp.38-47
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• 1999

We have designed a 16bit adder which reduces the power consumption at each level of architecture, logic and transistor. The conventional ELM adder has a major disadvantage which makes glitch in the G cell when the particular input bit patterns are applied, because of the block carry generation signal computed by the input bit pattern. Thus, we propose a low power adder architecture which can automatically transfer each block carry generation signal to the G cell of the last level to avoid glitches for particular input bit patterns at the architecture level. We also use a combination of logic styles which is suitable for low power consumption with static CMOS and low power XOR gate at the logic level. Futhermore, The variable-sized cells are used for reduction of power consumption according to the logic depth of the bit propagation at the transistor level. As a result of HSPICE simulation with $0.6\mu\textrm{m}$ single-poly triple-metal LG CMOS standard process parameter, the proposed adder is superior to the conventional ELM architecture with fixed-sized cell and fully static CMOS by 23.6% in power consumption, 22.6% in power-delay-product, respectively.

• The KSFM Journal of Fluid Machinery
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• v.5 no.1 s.14
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• pp.49-54
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• 2002

HANARO, 30 MW of research reactor, was installed at the depth of 13m in an open pool. The $90\%$ of primary coolant was designed to pass through the core and to remove the reaction heat of the cote. The rest, $10\%$, of the primary coolant was designed to bypass the core. And the reactor coolant through and bypass the core was inhaled at the top of chimney by the coolant pump to prevent the radiated gas from being lifted to the top of reactor pool. But, the part of core bypass coolant was not inhaled by the reactor coolant pump and reached at the top of reactor pool by natural convection, and increased the radiation lovel on the top of reactor pool. To reduce the radiation level by protecting the natural convection of the core bypass flow, the hot water layer (HWL, hereinafter) was installed with the depth of 1.2 m from the top of reactor pool. As the HWL was normally operated, the radiation level was reduced to five percent ($5\%$) in comparing with that before the installation of the HWL. When HANARO was operated at a higher temperature than the normal temperature of the HWL by operating the standby heater, it was found that the radiation level was more reduced than that before operation. To verify the reason, the heat loss of the HWL was calculated by Visual Basic Program. It was confirmed through the results that the larger the temperature difference between the HWL and reactor hall was, the more the evaporation loss increased. And it was verified that the radiation level above was reduced mote safely by increasing the capacity of heater.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.733-739
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• 2019

Water level measurement is highly demanding in IoT monitoring areas such as smart factory, smart farm, and smart fish farm. However, existing water level indicators are limited to be used in industrial fields as commercial products due to the high cost of sensors and the complexity of algorithms used. In order to solve these problems, our paper proposed methods using an infrared distance sensor as well as a hall sensor for the water level measurement, both of which are contactless smart sensors. Data errors caused by the inaccuracy of existing sensors were decreased by applying new simple structures so that versatility is enhanced. The performance of our method was validated using experiments based on simulations. We expect that our new water depth indicator can be extended to a general-purpose water level monitoring system based on IoT technology.

• Science of Emotion and Sensibility
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• v.16 no.1
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• pp.29-42
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• 2013

In this paper, we analyze the effect of the depth perception, volume perception and visual discomfort according to the change of the quality of the depth image and the depth of the major object. For the analysis, a 2D image was converted to eighteen 3D images using depth images generated based on the different depth position of a major object and background, which were represented in three detail levels. The subjective test was carried out using eighteen 3D images so that the degrees of the depth perception, volume perception and visual discomfort recognized by the subjects were investigated according to the change in the depth position of the major object and the quality of depth map. The absolute depth position of a major object and the relative depth difference between background and the major object were adjusted in three levels, respectively. The details of the depth map was also represented in three levels. Experimental results showed that the quality of the depth image differently affected the depth perception, volume perception and visual discomfort according to the absolute and relative depth position of the major object. In the case of the cardboard depth image, it severely damaged the volume perception regardless of the depth position of the major object. Especially, the depth perception was also more severely deteriorated by the cardboard depth image as the major object was located inside the screen than outside the screen. Furthermore, the subjects did not felt the difference of the depth perception, volume perception and visual comport from the 3D images generated by the detail depth map and by the rough depth map. As a result, it was analyzed that the excessively detail depth map was not necessary for enhancement of the stereoscopic perception in the 2D-to-3D conversion.

• Proceedings of the Acoustical Society of Korea Conference
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• 1997.06a
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• pp.68-74
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• 1997

Ship radiated noise is an infortant parameter which dtermines Anti Submarine Warfare(ASW) countermeansure or passive Sonar detection and classification performance. Its measurement should be performed under controlled ocean acoustic environment. In data reduction of the measured data from hydrophone array, theeffect fo ambient noise, surface reflection and bottom reflection etc. should be compensated to obtain the source level of the ship radiated noise. This study describes the measurement hydrophone array design criteria based on the analysis of transimission anomaly due to the surface reflection.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.1
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• pp.13-20
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• 1994

Status of endometrium is a very important factor which influences the implantation of fertilized embryos. In this study, we evaluated the possibility that the endometrial depth and pattern assessed by vaginal sonography on the day of human chorionic gonadotropin (HCG) injection in in vitro fertilization (IVF) cycles could be used to predict the IVF outcome. A total of 112 cycles using gonadotropin releasing hormone agonist (GnRHa) for ovulation induction were evaluated. We classified all patients into group A(<9mm) or group B(${\geq}$ 9mm) according to endometrial depth, and into group l(hyperechogenic), group 2(isoechogenic) or group 3(hypoechogenic and triple line) according to endometrial pattern. The other classification was made considering both endometrial depth and pattern. There was no significant correlation between serum estradiol level and endometrial sonographic findings(depth and pattern)(p>0.05). The pregnancy rate of group A(31.3%) did not differ significantly from that of group B(43.7%), but no pregnancies were found in any patients with endometrial depth less than 6mm. The pregnancy rate was 40%, 35.7%, and 44.6 % for group 1, gorup 2, and group 3, respectively, but there was no statistically significant difference between these groups(p>0.05). In combined classification, there was a trend of higher pregnancy rate in case of endometrial depth greater than 9mm and hypoechogenic triple line pattern, but there was no statistically significant differences between these groups(p>0.05). The conclusion from the present data is that endometrial ultrasonography on the day of hCG administration had no predictive value for conception in IVF cycles.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.135-143
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• 2019

Purpose of this study is enhancing usability of online video platform by analyze link-depth and advertisement frequency. In this study, researcher checked market share of video platform which publishing web-drama, and compare their link-depth and advertisement frequency. As a result, access to the latest content has two to three link-depth. So it does not worsen usability. but, if contents doesn't show on main page or search result, it requires more than five to six steps. Image advertisement show up more than twice on every platform. 'Youtube' and 'Naver TV' show up pre-roll video advertisement in video player before offering contents. In this video platform information structure, directory searching needs high link-depth level and advertisement frequency. It will increase user's bounce rate and decrease return visit rate. So researcher suggests prototype using drop-down menu to reduce link-depth and enhance information structure.

• The Korean Journal of Pain
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• v.35 no.3
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• pp.345-352
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• 2022

Background: Optimal needle depth in transforaminal epidural injection (TFEI) is determined by body measurements and is influenced by the needle entry angle. Physician can choose the appropriate needle length and perform the procedure more effectively if depth is predicted in advance. Methods: This retrospective study included patients with lumbosacral pain from a single university hospital. The skin depth from the target point was measured using magnetic resonance imaging transverse images. The depth was measured bilaterally for L4 and L5 TFEIs at 15°, 20°, and 25° oblique angles from the spinous process. Results: A total of 4,632 measurements of 386 patients were included. The lengths of the left and right TFEI at the same level and oblique angle were assessed, and no statistical differences were identified. Therefore, linear regression analysis was performed for bilateral L4 and L5 TFEIs. The R-squared values of height and weight combined were higher than the height, weight, and body mass index (BMI). The following equation was established: Depth (mm) = a - b (height, cm) + c (weight, kg). Based on the equation, maximal BMI capable with a 23G, 3.5-inch, Quincke-type point spinal needle was presented for three different angles (15°, 20°, and 25°) at lumbar levels L4 and L5. Conclusions: The maximal BMI that derived from the formulated equation is listed on the table, which can help in preparations for morbid obesity. If a patient has bigger BMI than the one in the table, the clinician should prepare longer needle than the usual spinal needle.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.645-660
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• 1998

The purpose of this study was to make and ascertain a decision making process on the base of patient-oriented utilitarianism in the treatment of patients of chronic adult periodontitis. Fifty subjects were chosen in Yonsei Dental hospital and the other fifty were chosen in Severance dental hospital according to the selection criteria. Fifty four patients agreed in this study. NS group(N=32) was treated with scaling and root planing without any surgical intervention, the other S group(N=22) done with flap operation. During the active treatment and healing time, all patients of both groups were educated about the importance of oral hygiene and controlled every visit to the hospital. When periodontal treatment needed according to the diagnostic results, some patients were subjected to professional tooth cleaning and scaling once every 3 months according to an individually designed oral hygienic protocol. Probing depth was recorded on baseline and 18 months after treatments. A questionnaire composed of 6 kinds(hygienic easiness, hypersensitivity, post treatment comfort, complication, functional comfort, compliance) of questions was delivered to each patient to obtain the subjective evaluation regarding the results of therapy. The decision tree for the treatment of adult periodontal disease was made on the result of 2 kinds of periodontal treatment and patient's ubjective evaluation. The optimal path was calculated by using the success rate of the results as the probability and utility according to relative value and the economic value in the insurance system. The success rate to achieve the diagnostic goal of periodontal treatment as the remaining pocket depth less than 3mm and without BOP was $0.83{\pm}0.12$ by non surgical treatment and $0.82{\pm}0.14$ by surgical treatment without any statistically significant difference. The moderate success rate of more than 4mm probing pocket depth were 0.17 together. The utilities of non-surgical treatment results were 100 for a result with less than 3mm probing pocket depth, 80 for the other results with more than 4mm probing pocket depth, 0 for the extraction. Those of surgical treatment results were the same except 75 for the results with more than 4mm. The pooling results of subjective evaluation by using a questionnaire were 60% for satisfaction level and 40% for no satisfaction level in the patient group receiving nonsurgical treatment and 33% and 67% in the other group receiving surgical treatment. The utilities for 4 satisfaction levels were 100, 75, 60, 50 on the base of that the patient would express the satisfaction level with normal distribution. The optimal path of periodontal treatment was rolled back by timing the utility on terminal node and the success rate, the distributed ratio of patient's satisfaction level. Both results of the calculation was non surgical treatment. Therefore, it can be said that non-surgical treatment may be the optimal path for this decision tree of treatment protocol if the goal of the periodontal treatment is to achieve the remaining probing pocket depth of less than 3mm for adult chronic periodontitis and if the utilitarian philosophy to maximise the expected utility for the patients is advocated.

• Nuclear Engineering and Technology
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• v.44 no.1
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• pp.89-102
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• 2012

The buffer and backfill are important components of the engineered barrier system in a high-level waste repository, which should be constructed in a hard rock formation at a depth of several hundred meters below the ground surface. The primary function of the buffer and backfill is to seal the underground excavation as a preferred flow path for radionuclide migration from the deposited high-level waste. This study investigates the hydraulic conductivity and swelling pressure of Kyungju Ca-bentonite, which is the candidate material for the buffer and backfill in the Korean reference high-level waste disposal system. The factors that influence the hydraulic conductivity and swelling pressure of the buffer and backfill are analyzed. The factors considered are the dry density, the temperature, the sand content, the salinity and the organic carbon content. The possibility of deterioration in the sealing performance of the buffer and backfill is also assessed.