• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.11
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• pp.770-775
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• 2007

Although these days application of heat recovery ventilation and improved kitchen ventilation system came into wide use in mixed-use residential buildings and exclusive residences, there are not enough ventilation systems except the local ventilation of kitchens and rest rooms. It is very important part to regulate and distribute correct air flow rate for controlling air change rate. The purpose of this study is to investigate the application of distributor at house ventilation system by comparing a duct system with out distributor and with distributor. The results of this study are as follows. (1) When using distributor though the size of duct diameter is reduced rapidly, the pressure loss doesn't rise largely. The pressure loss without distributor is 4.08 mmAq, the pressure loss with distributor 4.10 mmAq. (2) To use distributor can reduce materials of duct and secure enough ceiling space by reducing duct diameter. (3) Diameters and air flow paths of distributor on the design stage are important part for accurate air flow rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.7
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• pp.553-563
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• 2013

When the IEEE 802.11 wireless LAN-based broadcasting services, we use broadcast packets to broadcast multimedia contents to a large number of users using limited wireless resources. However, broadcast transmission is difficult to recover the loss packets compared with unicast transmission. Therefore, analysis of packet loss characteristics is required to perform efficient packet recovery. The packet loss in wireless transmissions is often bursty with high loss data rate. Even if loss patterns have the same average packet loss, they are different in the recovery rate of random loss and burst loss depending on the nature. Therefore, the analysis and research of the nature of the loss are needed to recover loss packets considering bursty characteristics. In this paper, we experimented Wi-Fi broadcast transmission according to transmission rate and analyzed bursty characteristics of loss patterns using 4-state markov model.

• Journal of Trauma and Injury
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• v.32 no.4
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• pp.195-201
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• 2019

Purpose: This study was conducted to investigate the usefulness of a polyester urethane dural substitute (Neuro-Patch^®, B. Braun, Boulogne, France) as an anti-adhesion agent in subsequent cranioplasty by analyzing the use of Neuro-Patch^® during decompressive craniectomy in traumatic brain injury patients. Methods: We retrospectively analyzed patients with traumatic brain injury who underwent decompressive craniectomy followed by cranioplasty from January 2015 to December 2018. Patients were analyzed according to whether they received treatment with Neuro-Patch^® or not (Neuro-Patch^® group, n=71; control group, n=55). Patients' baseline characteristics were analyzed to identify factors that could affect cranioplasty results, including age, sex, hypertension, diabetes mellitus, use of antiplatelet agents or anticoagulant medication, the interval between craniectomy and cranioplasty, and the type of bone used in cranioplasty. The cranioplasty results were analyzed according to the following factors: operation time, blood loss, postoperative hospitalization period, surgical site infection, and revision surgery due to extra-axial hematoma. Results: No significant difference was found between the two groups regarding patients' baseline characteristics. For the cranioplasty procedures, the operation time (155 vs. 190 minutes, p=0.003), intraoperative blood loss (350 vs. 450 mL, p=0.012), and number of surgical site infections (4 vs. 11 cases, p=0.024) were significantly lower in the Neuro-Patch^® group than in the control group. Conclusions: The use of Neuro-Patch^® was associated with a shorter operation time, less blood loss, and a lower number of surgical site infections in subsequent cranioplasties. These results may provide a rationale for prospective studies investigating the efficacy of Neuro-Patch^®.

• Advances in concrete construction
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• v.16 no.1
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• pp.1-20
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• 2023

This study presents the experimental results performed to evaluate the effects of Polyvinyl-alcohol (PVA) and Polypropylene (PP) fibers on the fresh and residual mechanical properties of the hybrid fiber reinforced SCC before and after the exposure of 250℃, 500℃ and 750℃ temperatures. The compressive and splitting tensile strength, modulus of rupture (MOR), ultrasonic pulse velocity (UPV) as well as toughness and weight loss were investigated at different temperatures. PVA and PP fibers were added into SCC mixtures having only macro steel fiber and also having binary hybridization of both macro and micro steel fiber. The results showed that the use of micro steel fiber replaced by macro steel fiber improved the fresh and hardened properties compared to the use of only macro steel fiber. Moreover, it was emphasized that PVA or PP enhanced the residual flexural performance of SCC, generally, while it negatively influenced the workability, weight loss, UPV and the residual strengths with regards to the use of single steel fiber and binary steel fiber hybridization. Compared to the effect of synthetic fibers, PP had slightly more positive effect in the view of workability while PVA enhanced the residual mechanical properties more.

• Speech Sciences
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• v.12 no.4
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• pp.197-202
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• 2005

The cochlear implantation(CI) as an useful tool for aural rehabilitation in bilateral severe to profound hearing impairment. However, CI prefer to usually one ear in spite of bilateral hearing impaired. because of the various characteristics of hearing loss, the hearing conservation for the future possibility, and socioeconomic condition of hearing impaired person and their families. The unilateral CI has limitations such as a directional loss, a difficult speech understanding in noise and a neural plasticity. These limitations will be overcome by hearing aid(HA) which is familiar with hearing impairer. but HA fitting for bimodal-binaural hearing are difficult because the difference output characteristic of HA and CI. This study will be confirm realities of use of HA in unilateral cochlear implantee. For this goal, 25(m:f=10:15) child participated who are used to HA for 1 to 17 months. We had telephone interviews with their mother about use of HA, change of auditory performance and own voice. As the results, hearing threshold levels of unimplanted ear, the use of a appropriate HA, implanted and aided hearing threshold level(HTL) are must be considered for successful biomodal-binaural hearing. Especially, implanted and aided HTL should be very useful parameter for a prediction of HA effect and a criterion of selection for bilateral cochlear implantation.

• Journal of Audiology & Otology
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• v.25 no.1
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• pp.8-13
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• 2021

Background and Objectives: In 2013, the Singapore government reviewed and expanded the Senior Mobility Fund (SMF) to provide subsidy for assistive devices, including hearing aids (HA). While SMF has improved accessibility to HA, its impact on HA acquisition has not been determined. The study aims to elucidate the influence of SMF on HA acquisition and the relationship between financial funding and compliance to HA use. Subjects and Methods: Retrospective review of 643 patients seen between January 2017 to January 2018 at the earnose and throat specialist outpatient clinic, who were referred for a hearing aid evaluation. Of the 643 patients, 109 patients with baseline hearing handicap (HH) scores recorded, and no formal diagnosis of cognitive impairment were included. The patients were grouped according to SMF eligibility and clinical data were obtained. Results: The odds ratio for acquiring HA was significantly higher with SMF, regardless of HH scores. When looking at actual degree of hearing loss (DHL), HA uptake was significantly higher in the least severe of DHL categories. There is no relationship between SMF and compliance to HA use. However, HH score is positively correlated with data log in regression analyses. Conclusions: SMF appears to influence HA acquisition. Especially in financially funded patients with low self-perceived HH, the benefits of HA may be underappreciated given the few hours of HA use. Further studies are warranted to investigate the impact of financial funding on outcomes of HA users to help policy planners and clinicians be prudent in the utilization of SMF.

• Korean Journal of Audiology
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• v.25 no.1
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• pp.8-13
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• 2021

Background and Objectives: In 2013, the Singapore government reviewed and expanded the Senior Mobility Fund (SMF) to provide subsidy for assistive devices, including hearing aids (HA). While SMF has improved accessibility to HA, its impact on HA acquisition has not been determined. The study aims to elucidate the influence of SMF on HA acquisition and the relationship between financial funding and compliance to HA use. Subjects and Methods: Retrospective review of 643 patients seen between January 2017 to January 2018 at the earnose and throat specialist outpatient clinic, who were referred for a hearing aid evaluation. Of the 643 patients, 109 patients with baseline hearing handicap (HH) scores recorded, and no formal diagnosis of cognitive impairment were included. The patients were grouped according to SMF eligibility and clinical data were obtained. Results: The odds ratio for acquiring HA was significantly higher with SMF, regardless of HH scores. When looking at actual degree of hearing loss (DHL), HA uptake was significantly higher in the least severe of DHL categories. There is no relationship between SMF and compliance to HA use. However, HH score is positively correlated with data log in regression analyses. Conclusions: SMF appears to influence HA acquisition. Especially in financially funded patients with low self-perceived HH, the benefits of HA may be underappreciated given the few hours of HA use. Further studies are warranted to investigate the impact of financial funding on outcomes of HA users to help policy planners and clinicians be prudent in the utilization of SMF.

• Journal of Periodontal and Implant Science
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• v.50 no.4
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• pp.209-225
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• 2020

Purpose: Marginal bone loss (MBL) is an important clinical issue in implant therapy. One feature that has been cited as a contributing factor to this bone loss is peri-implant mucosal thickness. Therefore, in this report, we conducted a systematic review of the literature comparing bone remodeling around implants placed in areas with thick (≥2-mm) vs. thin (<2-mm) mucosa. Methods: A PICO question was defined. Manual and electronic searches were performed of the MEDLINE/PubMed and Cochrane Oral Health Group databases. The inclusion criteria were prospective studies that documented soft tissue thickness with direct intraoperative measurements and that included at least 1 year of follow-up. When possible, a meta-analysis was performed for both the overall and subgroup analyses. Results: Thirteen papers fulfilled the inclusion criteria. A meta-analysis of 7 randomized clinical trials was conducted. Significantly less bone loss was found around implants with thick mucosa than around those with thin mucosa (difference, -0.53 mm; P<0.0001). Subgroups were analyzed regarding the apico-coronal positioning, the use of platform-matched vs. platform-switched (PS) connections, and the use of cement-retained vs. screw-retained prostheses. In these analyses, thick mucosa was found to be associated with significantly less MBL than thin mucosa (P<0.0001). Among non-matching (PS) connections and screw-retained prostheses, bone levels were not affected by mucosal thickness. Conclusions: Soft tissue thickness was found to be correlated with MBL except in cases of PS connections used on implants with thin tissues and screw-retained prostheses. Mucosal thickness did not affect implant survival or the occurrence of biological or aesthetic complications.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.3
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• pp.29-42
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• 2023

Universal Soil Loss Equation (USLE) is suggested and employed in the policy to conserve soil resources and to manage the impact of development, since soil loss is very essential to nonpoint source pollution management. The equation requires only five factors to estimate average annual potential soil loss, USLE is simplicity provides benefits in use of the equation. However, it is also limitation of the model, since the estimated results are very sensitive to the five factors. There is a need to examine the application procedures. Three approaches to estimate potential soil loss were examined, In the first approach, all factors were prepared with raster data, soil loss were computed for each cell, and sum of all cell values was determined as soil loss for the watersheds. In the second approach, the mean values for each factor were defined as representing USLE factors, and then the five factors were multiplied to determine soil loss for the watersheds. The third approach was same as the second approach, except that the Vegetative and Mechanical measure was used instead of the Cover and management factor and Support practice factor. The approaches were applied in 38 watersheds, they displayed significant difference, moreover no trends were detected for the soil loss at watersheds with the approaches. Therefore, it was concluded that there is a need to be developed and provided a typical guideline or public systems so that soil loss estimations have consistency with the users.

• Textile Coloration and Finishing
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• v.3 no.4
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• pp.7-12
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• 1991

Wool gabardines were treated with alkaline proteases, and their tensile strerigth and dyeing behavior were obtained. Enzylon ASA 30 and Alcalase 2.5L DX did not show much effect on the weight loss of wool, but Esperase 8.0L decreased the weight of wool to a great extent. Pretreatment of wool with dichloroisocyarturic acid before protease-treatment increased the weight loss of wool considerably. Weight loss was accompanied by serious strength decrease and the use of sodium sulfate in the protease-treatment had not effect on the strength retention, only lowering the weight loss of wool. Protease-treatment of wool increased dyeability considerably, which may be due to the change in the inner structure of wool fiber by protease.