• Membrane Journal
• /
• v.20 no.3
• /
• pp.222-227
• /
• 2010

The purpose of this study is to prepare forward osmosis (FO) membranes using a variety of cellulose-based polymers and to evaluate the performance of difference depending on each of the polymers and additives. Forward osmosis membranes based on cellulose acetate (CA) and cellulose triacetate (CTA) were prepared through phase inversion. The performance of FO membranes developed, such as flux and salt rejection, was compared under the osmotically- and pressure-driven conditions. In CA FO membranes, the execution time of solvent evaporation and membrane annealing induced the change in membrane performance. But the performance of CTA FO membrane was improved by using additives rather than annealing. Moreover, the flux of CTA FO membrane was $4.46\;L/m^2hr$ but that of CA/CTA FO membrane was $8.89\;L/m^2hr$ in FO mode. The CTA FO membrane with blending CA was more efficient to increase FO permeate flow rather than using a single polymer membrane.

• Journal of Satellite, Information and Communications
• /
• v.10 no.1
• /
• pp.12-16
• /
• 2015

In this paper, we introduce a wireless package system based on the amateur radio HR(HAM Radio) and satellite communication as a novel wireless disaster communication system and have configured a interference scenario receiving interference from adjacent base stations and D2D groups in the disaster network. In such interference scenarios, we propose a frequency re-allocation method to avoid interference and communicate with disaster networks by securing the channel capacity required between D2D terminals. As a result of computer simulation, we can find the proposed method has improved BED performance of a gain of 1.5dB and overall system throughput than conventional methods.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.12
• /
• pp.5594-5600
• /
• 2011

Even though many studies have showed that competence is positively related to organizational performance, few studies have attempted to find out the process of competency - performance. This study focuses on the organizational factors to explore their effect on the competence of customer relationship. Based on the data collected by KRIVET and the Ministry of employment and labor, strategic role of HR department and information systems are examined. As well human resource competency is investigated as a mediating variable. This study used surveys targeting department managers and executive members in firms and sample size was 1086 after cleaning the dataset by deleting all the cases with many missing values. The findings show that strategic role of HR department and information system has an influence on human resource competency, significantly. In addition, the human resource competency affect customer relationship competency, positively. Implications and directions for future research are discussed.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.21 no.3
• /
• pp.82-92
• /
• 2013

The Intermittent Aeration MBR systems have the advantage of controlling reaction time by changing aeration period and are one of economic BNR systems since these processes do not require MLSS recirculation that demands capital and operation costs. In this study, two intermittent aeration MBR systems were studied by computer simulation: an intermittent aeration MBR system that had both 1hr/1hr and 4hr/4hr aeration/unaeration periods at intermittent reactor and NEW INTERMITTENT-process that was an energy saving process and certified as a new process by Korean government. Since DO concentration reached only at 0.23mg/L at intermittent reactor when it was aerated, the Intermittent aeration MBR system having 1hr/1hr aeration/unaeration period showed simultaneous nitrification/denitrification and had the highest nitrogen and phosphorus removal efficiencies that were 57% and 55%, respectively. Since this study was based on the constant influent flow and characteristics, more studies are needed to define the operational characteristics of intermittent aeration MBR systems under dynamic influent conditions.

• The Journal of the Korea Contents Association
• /
• v.13 no.2
• /
• pp.412-419
• /
• 2013

Firm's competitive advantage and profitability can be gained over competitors by human resources and human resource management that are characterized by idiosyncrasies or differentiation. Yet, the results of previous studies have been a emerging consensus that the isomorphism and homogeneity of HRM and HR practices among firms regardless of thoese industrial areas, size, organizational settings, etc. are universal. Based on the previous studies of similarities of HRM, the paper theoretically investigates the background and reasons of introducing similar HR practices among firms. The paper shows the dynamism of HR system in Korean firms, adapting a new HR system. Three types of reasons are found, coercive isomorphism, mimetic isomorphism, and normative isomorphism. However, it is also discussed that there is an important gap in the theoretical and empirical research. More empirical research is suggested in order for gaining meaningful results on HR studies.

• Journal of Veterinary Clinics
• /
• v.30 no.6
• /
• pp.435-441
• /
• 2013

This retrospective study evaluated the effects of the interval from calving to first insemination (ICFI) and days open (DO) on the reproductive performance in dairy cows. In the first analysis, data from 705 cows were grouped based on the ICFI: short (30-60 days, n=217), medium (61-90 days, n=309), and long (91-150 days, n=179). The occurrence of endometritis was greater in the long group than in short and medium groups (p<0.05). The occurrence of ovarian cysts increased with increasing ICFI (p<0.05), while body condition score (BCS) during the 5 month postpartum period was lower with increasing ICFI (p<0.01). The hazard of pregnancy by 365 days in milk (DIM) was lower (hazard ratio [HR]=0.70, p<0.0001) in the long group, but higher (HR=1.41, p<0.0001) in the short group compared with the medium group. In the second analysis, data from 436 cows were grouped based on the DO: short (30-90 days, n=154), medium (91-180 days, n=183), and long (181-360 days, n=99). The occurrence of a retained placenta was greater in the long group than in the medium group (p < 0.05). Ovarian cysts occurred more frequently in medium and long groups than in the short group (p=0.08). BCS was lower in the short group compared with medium and long groups at month 1 postpartum (p<0.05). Milk yield (kg/day) was greater in the medium group compared with the short group at months 2 to 5 postpartum (p<0.05). The hazard of first insemination by 150 DIM was lower in the long group than in the short group (HR=0.73; p<0.02). The hazard of pregnancy by 365 DIM was lower (HR=0.64, p<0.0001) in the long group than in the medium group, while the hazard did not differ between short and medium groups (p>0.05). Moreover, the culling rate was greater in the long group than in the short group (p<0.05). In conclusion, a longer ICFI and DO resulted in reduced reproductive performance in dairy cows, which was attributable to an increase in postpartum diseases, a lower BCS and a greater milk yield.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.11
• /
• pp.1-8
• /
• 2011

In this paper, we study receiver design issue to apply the OFDM based WLAN specification, such as 802.11p, to the communications in high speed mobile environment, e.g., for the ICT based railroad control on a train having its speed up to 300 km/hr. To successfully apply the existing WLAN specifications without modifying its transmission format, the performance at the receiver will solely depends on the channel estimation performance if we ignore the affect of frequency offset With a speed of multiple hundred km/hr, the channel estimation using only the preamble will not provide enough precision since the channel changes so fast. Therefore, in this paper, taking the high mobility into account, we focus on the design of decision directed channel estimation and equalization techniques and perform simulations to evaluate and compare their performances and to finally confirm the applicability of the existing WLAN specification to the systems with very high mobility.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.153-156
• /
• 2009

The interferometric fiber optic gyroscopes (FOGs) are well known as sensors of rotation, which are based on Sagnac effect, and have been under development for a number of years to meet a wide range of performance requirements. This paper describes the development of open-loop FOG and digital signal processing techniques implemented on FPGA. Our primary goal was to obtain intermediate accuracy (pointing grade) with a good bias stability ($0.22^{\circ}/hr$) and scale factor stability, extremely low angle random walk ($0.07^{\circ}/\sqrt{hr}$) and significant cost savings by using a single mode fiber. A secondary goal is to design all digital FOG signal processing algorithms with which the SNR at the digital demodulator output is enhanced substantially due to processing gain. The CIC type of decimation block only requires adders and shift registers, low cost processors which has low computing power still can used in this all digital FOG processor.

• Korean Journal of Radiology
• /
• v.25 no.7
• /
• pp.644-655
• /
• 2024

Objective: To develop and validate a preoperative risk score incorporating carbohydrate antigen (CA) 19-9, CT, and fluorine18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT variables to predict recurrence-free survival (RFS) after upfront surgery in patients with resectable pancreatic ductal adenocarcinoma (PDAC). Materials and Methods: Patients with resectable PDAC who underwent upfront surgery between 2014 and 2017 (development set) or between 2018 and 2019 (test set) were retrospectively evaluated. In the development set, a risk-scoring system was developed using the multivariable Cox proportional hazards model, including variables associated with RFS. In the test set, the performance of the risk score was evaluated using the Harrell C-index and compared with that of the postoperative pathological tumor stage. Results: A total of 529 patients, including 335 (198 male; mean age ± standard deviation, 64 ± 9 years) and 194 (103 male; mean age, 66 ± 9 years) patients in the development and test sets, respectively, were evaluated. The risk score included five variables predicting RFS: tumor size (hazard ratio [HR], 1.29 per 1 cm increment; P < 0.001), maximal standardized uptake values of tumor ≥ 5.2 (HR, 1.29; P = 0.06), suspicious regional lymph nodes (HR, 1.43; P = 0.02), possible distant metastasis on ¹⁸F-FDG PET/CT (HR, 2.32; P = 0.03), and CA 19-9 (HR, 1.02 per 100 U/mL increment; P = 0.002). In the test set, the risk score showed good performance in predicting RFS (C-index, 0.61), similar to that of the pathologic tumor stage (C-index, 0.64; P = 0.17). Conclusion: The proposed risk score based on preoperative CA 19-9, CT, and ¹⁸F-FDG PET/CT variables may have clinical utility in selecting high-risk patients with resectable PDAC.

• Asia-Pacific Journal of Business
• /
• v.5 no.2
• /
• pp.51-64
• /
• 2014

Strategic bundling of Human Resource Management (HRM) practices among themselves works together as an entire HRM system rather than individual HRM practices to achieve organizational objectives. The bundles of HR practices support the effectiveness of one another assuming the effectiveness of any practice depends on other practices in place. It is said that the greater the total degree of bundling among the various components of HRM policies and practices, the more will be the organizational outcomes. Realizing these facts, this study aimed to explore the level of strategic bundling and examined the impact of such bundling on organizational performance to the publicly listed companies of Nepal. This empirical study is based on description and exploratory design for which data collected through the questionnaire based on 5-point liker scale. Total population of the study at the time of data collection are 234 organizations publicly listed in Stock Exchange of Nepal. Questionnaire is distributed to all organizations listed, response received from 105 organizations, as a unit of analysis, which is fairly good response. The study of strategic bundling of HRM practices perhaps the first study in Nepal, found that only 32 percent organizations have followed high bundling HR practices and these high bundling organizations are significantly different with low bundling organizations. Business organizations are trying to practice being close association of HRM policies and practices within them except labor relation with employee participation and business strategies. Supporting to the international literature, strategic bundling of HRM practices among themselves shows statistically significant effects on quality of product or services, labor productivity, financial performance, employee satisfaction, rate of innovation, employee commitment and market share.