• Journal of Home Health Care Nursing
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• v.17 no.2
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• pp.144-155
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• 2010

Purpose: This study investigated the factors affecting the quality of life (QOL) of the primary caregivers of home health care patients. Method: The subjects were 110 primary caregivers of patients who were receiving home health care from two home health care centers affiliated with general hospitals in Seoul. Data collection was conducted using five questionnaires. Results: Positive relationships were evident between QOL and social support and perceived health status of the primary caregiver. Negative relationships were evident between QOL and burden and depression. Multiple linear regression analysis for QOL revealed that the most powerful influencing factor was social support. Social support, burden, and depression explained 34.3% of the variance. Conclusion: Burden, depression, and social support are related with QOL of primary caregivers of home health care patients. Nursing intervention strategies directed at this caregiver population are needed.

• Journal of Gastric Cancer
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• v.3 no.3
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• pp.139-144
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• 2003

Purpose: Because of an improving gastric cancer detection program and treatment methods, we can expect improved survival of patients with gastric cancer. Given the longer survival times, the chance of an occurrence of multiple primary malignant tumors other than stomach is increased in the same patients. The purpose of this study is to analyze the clinical characteristrics and the survival of patients with gastric cancer and other malignancies. Materials and Methods: A retrospective study of 3669 patients with gastric cancer observed at our department between January 1994 to December 2002 was conducted. Associated tumors were diagnosed using the Warren and Gates criteria, and included tumors that were not considered to be a metastasis, invasion, or recurrence of the gastric cancer. Results: Of all 3669 patients, $2.07\%$ (n=76) had primary tumors other than gastric cancer, $63\%$ of which were synchronous (n=48) and $37\%$ metachronous (n=28). The mean age of the study group was 64.9 (65.5 in males, 61.8 in females), and the male-to-female ratio was 4.8 : 1. The most common cancer associated with gastric cancer was a hepatocellular carcinoma ($23.7\%$), followed by colorectal cancer ($17.1\%$), esophageal cancer ($10.5\%$), breast cancer ($6.6\%$). Of the 45 patients who had undergone a resection, 14 were in stage I, 12 in stage II, 13 in stage III, and 6 in stage IV. No statistically significant differences were found between the synchronous and the metachronous groups with regard to age, sex ratio, differentiation, and stage. The 5-year survival rates of the metachronous and the resected patients were significantly higher than those of the synchronous and the non resected patients, respectively. Conclusion: Due to increasing length of the follow-up period for patients with gastric cancer, another malignancy may develop in other organs. Therefore, physicians should pay attention to detect other cancers early in these patients, and a surgical resection is recommended as the treatment of choice in the management of multiple primary cancer associated with gastric cancer.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.199-205
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• 2002

Purpose : This study was peformed to determine the optimal radiation therapy field for the treatment of malignant astrocytoma and glioblastoma multiforme. Materials and Methods : From Jan. 1994 to Mar. 2000, 21 patients with malignant astrocytoma and glioblastoma multiforme, confirmed as recurrent by follow up MRI after surgery and radiation therapy, were analyzed. The distance from the margin of the primary lesion to the recurrent lesion was measured. The following factors were analyzed to Investigate the influence of these factors to recurrence pattern; tumor size, degree of edema, surgical extent, gamma knife radiosurgery and multiple lesions. Results : Among the 21 patients, 18 $(86\%)$ were recurred within 2 cm from the primary lesion site. 12 within 1 cm, 6 between 1 and 2 cm. The other 3 patients all with multiple lesions, were recurred at 3, 4, 5 cm, from the primary lesion site. The recurrence pattern was not influenced by the factors of tumor size, extent of edema, surgical extent, or gamma knife radiosurgery. However, patients with multiple lesions showed a tendency of recurrence at sites further from the primary lesion. Conclusions : Most $(86\%)$ of the recurrences of malignant astrocytoma and glioblastoma multiforme occurred within 2 cm from the primary lesion site. The width of treatment field does not need to be changed according to tumor size, degree of edema, surgical extent, or gamma knife radiosurgery. However, the treatment field for multiple lesions appears to be wider than that for a single lesion.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.31-39
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• 2002

A rapid growth of internet and sudden increase of multimedia data demands for high-speed transfer media and if optimizec usage from the interface system. To achieve this level of network bandwidth, multiple NICs for support of high-speed network bandwidth have been developed and studied. Furthermore, the use of multiple NICs can provide high-speed LAN environment without large network environment modification, supports backward compatibility of current system and reduce overhead. However. if system failure is caused by SPOF(Single Point of Failure) fault of large-capacity multiple NICs, incredible loss will be met because it services large capacity of multimedia data, Therefore, to prevent loss coming from faults, we describe 'Fault tolerance of multiple NICs', which use the fault prevention mechanism. Considering inefficiency of availability and serviceability that is occurred with existing TMR, Primary-Standby approach and Watchdog time mechanism, we propose and design the efficient fault tolerance mechanism, which minimize down time as changing of detection period dynamically. Consequently, the fault tolerance mechanism proposed for reducing overhead time when the fault is occurred, should minimize system downtime overall.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.237-240
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• 2005

We present images of L1551 IRS5 at angular resolutions as high as ${\~}$30 mas, corresponding to a spatial resolution of ${\~}$5 AU, made at 7 mm with the VLA. Previously known to be a binary protostellar system, we show that L1551 IRS5 is likely a triple protostellar system. The primary and secondary components have a projected separation of ${\~}$46 AU, whereas the tertiary component has a projected separation of ${\~}$11 AU from the primary component. The circumstellar dust disks of the primary and secondary components have dimensions of ${\~}$15 AU, whereas that of the tertiary component has a dimension of ${\~}$10 AU. Their major axes are closely, but not perfectly, aligned with each other, as well as the major axis of the surrounding flattened, rotating, and contracting molecular condensation (pseudodisk). Furthermore, the orbital motion of the primary and secondary components is in the same direction as the rotational motion of this pseudodisk. We suggest that all three protostellar components formed as a result of the fragmentation of the central region of the molecular pseudo disk. The primary and secondary components, but apparently not the tertiary component, each exhibits a bipolar ionized jet that is centered on and which emergers perpendicular to its associated dust disk. Neither jets are resolved along their base, implying that they are driven within a radial distance of ${\~}$2.5 AU from their central protostars. Finally, we show evidence for what may be dusty matter streams feeding the two main protostellar components.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1108-1114
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• 2001

Objective : Prognostic factors of metastatic brain tumors have been widely reported and their operative indications also have been extended gradually even to the poor grade patients. Authors intended to analyze the causative factors for the clinical outcome of metastatic brain tumors, especially with relevant to the poor prognosis by one year follow-up evaluation. Patients and Methods : The authors retrospectively studied the clinical characteristics of 46 cases(35 patients) with metastatic brain tumors among 466 cases(437 patients) which were operated on due to the brain tumor, during the period between January 1994 to June 1999. Statistical analysis was performed by using SPSS 8.0$^{(R)}$. A p-value of less than 0.05 was considered clinically significant. Result : Among the variable clinical factors in patients with metastatic brain tumors, Karnofsky Performance Scale (KPS) score of less than 70(16 patients), uncontrolled primary tumor(8 patients), and surgical resection without further adjuvant therapy(9 patients) showed statistically significant poor prognosis ; p value of 0.002, 0.032, and 0.001, respectively. Other tested variables, such as old age(greater than 65 years ; 10 patients), gender(male ; 20 patients), type of primary cancer(primary undefined ; 6 patients, lung cancer ; 15 patients), location(infratentorial ; 9 patients, sellar ; 5 patients), number of lesion(multiple ; 12 patients), and number of operation(multiple craniotomy ; 7 patients) were not related to the poor prognosis. Conclusions : The most common primary site of distant metastasis was lung. The poorer prognosis was highly correlated with various factors including low KPS score(<70), no postoperative adjuvant therapy, and uncontrolled primary tumors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.6
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• pp.1379-1397
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• 2013

We consider a system where a licensed radio spectrum is shared by multiple primary users(PUs) and secondary users(SUs). As the spectrum of interest is licensed to primary network, power and channel allocation must be carried out within the cognitive radio network so that no excessive interference is caused to PUs. For this system, we study the joint beamforming and power allocation problem via game theory in this paper. The problem is formulated as a non-cooperative beamforming and power allocation game, subject to the interference constraints of PUs as well as the peak transmission power constraints of SUs. We design a joint beamforming and power allocation algorithm for maximizing the total throughput of SUs, which is implemented by alternating iteration of minimum mean square error based decision feedback beamforming and a best response based iterative power allocation algorithm. Simulation results show that the algorithm has better performance than an existing algorithm and can converge to a locally optimal sum utility.

• Journal of Magnetics
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• v.21 no.3
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• pp.330-339
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• 2016

A magnetic field sensing system with a single primary sensor and multiple reference sensors deployed locally and orthogonally, was proposed for downlink signal reception and interference cancelling for Through-the-Earth Communication (TEC). This paper mathematically analyzes a design optimization process for a search coil magnetometer (SCM), and applies that process to minimize the bandwidth of the primary SCM for TEC signal reception and the volume of reference SCMs for multiple distributions. The primary SCM achieves a 3-dB bandwidth of 7 Hz, a sensitivity threshold of 120 fT/${\surd}$Hz, and a volume of $2.32{\times}10^{-4}m^3$. The entire sensing system volume is as small as $10^{-2}m^3$. Experiments with interference from industrial frequency harmonics demonstrated an average of 36 dB and 18 dB improvements in signal-to-interference ratio and signal-to-interference plus noise ratio, respectively, using multichannel recursive-least-squares algorithm. Thus, the proposed sensing system can reduce the interference effectively and allows reliable downlink signal reception.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.573-576
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• 1996

Multiple primary cancer is a disease of more than two cancers occurring in an individual indepen- dently. We experienced a case of triple primary cancer, that is, lung cancer, malignant thymoma and bladder cancer which has not been reported in Korea. The patient was a 60 year old man with dyspnea and chest discomfort. He was rirst diagn sed bladder cancer and received Bricker's operation 3 months ago. At that time the chest roentgenography and computerized tomographic scan revealed as a preaortic, retrosternill medidstin;11, nlass and a lung mass at the posterior portion of the left lower lobe. On operation, there was An identillable lung mass in the left lower lobe and a thymoma already invaded the surrounding structures. So, left lower lobectomy and thymectomy were performed simul- taneously. He received one cycle of postoperative chemotherapy, but refused further management and self-discharged. He died, about one year later.

• Journal of Communications and Networks
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• v.15 no.1
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• pp.102-110
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• 2013

This paper considers a cooperative orthogonal frequency division multiple access (OFDMA)-based cognitive radio network where the primary system leases some of its subchannels to the secondary system for a fraction of time in exchange for the secondary users (SUs) assisting the transmission of primary users (PUs) as relays. Our aim is to determine the cooperation strategies among the primary and secondary systems so as to maximize the sum-rate of SUs while maintaining quality-of-service (QoS) requirements of PUs. We formulate a joint optimization problem of PU transmission mode selection, SU (or relay) selection, subcarrier assignment, power control, and time allocation. By applying dual method, this mixed integer programming problem is decomposed into parallel per-subcarrier subproblems, with each determining the cooperation strategy between one PU and one SU. We show that, on each leased subcarrier, the optimal strategy is to let a SU exclusively act as a relay or transmit for itself. This result is fundamentally different from the conventional spectrum leasing in single-channel systems where a SU must transmit a fraction of time for itself if it helps the PU's transmission. We then propose a subgradient-based algorithm to find the asymptotically optimal solution to the primal problem in polynomial time. Simulation results demonstrate that the proposed algorithm can significantly enhance the network performance.