• 대한전자공학회논문지TC
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• 제44권7호통권361호
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• pp.70-80
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• 2007

차세대 이동 네트워크에서는 다양한 무선 접속 기술이 공존하게 된다. 이에 따라, 다양한 무선망에서 QoS를 지원하는 분산 방식의 호 수락 제어 구조인 SmartCAC를 제안한다. 본 논문은 네트워크간 정보 수집이 필요없는 분산방식을 위하여 모바일 노드와 네트워크간의 상호동작을 이용한다. SmartCAC는 기본적으로 VHO 호와 새로운 호1의 구분이 가능하도록 함으로써 VHO 호에 핸드오프를 위해 예약된 채널을 사용할 수 있도록 한다. 또한, 효율적인 호 수락 제어를 위하여 QoS 요구와 네트워크 사용에 대한 delay와 reliability를 다룬다. 뿐만 아니라, 이종망에서 네트워크 필터링을 할 수 있도록 모바일노드의 스피드를 이용한다. 이종망의 상태정보를 알 수 없는 모바일노드가 네트워크의 상태정보를 받아 비교할 수 있도록 확장된 프로토콜을 제시하고, 시뮬레이션 연구에서 기존의 CAC 방식과 제어메시지에 의한 비용을 비교하여 37%에서 96%까지 향상되는 효과를 입증한다.

• 보건행정학회지
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• 제30권3호
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• pp.418-429
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• 2020

Background: This study aims to analyze the cost and the length of stay (LOS) of acute myocardial infarction (AMI) patients with coronary artery stenting according to the characteristics of individuals and institutions. Methods: The data was collected from Korean National Health Insurance Service's customized database in 2010 and 2015. Chi-square test, t-test, analysis of variance, and multilevel analysis were performed. Results: The intraclass correlation coefficients for cost were 7.02% in 2010, 5.61% in 2015 and for LOS were 3.17%, 1.40%, respectively. The average costs were 9,067,000 won in 2010 and 9,889,000 won in 2015 (p<0.0001). However, the cost in 2015 was lower than the cost applying increased fee. The costs increased in aged 50-59 years, 60-69 years, and aged ≥70 years versus in aged under 49 years. The cost was higher in Charlson comorbidity index (CCI) 3 to 4 and ≥5 than in CCI 0. The costs were lower in male, medical aid recipients, metropolises, and local hospitals in other regions in 2010. LOS decreased from 8.1 days in 2010 to 7.4 days in 2015. It decreased in male, high income group, and the group of admission via emergency room. However, it increased in higher ages and medical aid recipients, and it also increased when CCI rose. The Internal Herfindahl Index was related to LOS in 2010. Conclusion: The variation of hospital level was small compared to the patient level. Therefore, it is important to implement applicable policies at the patient level in order to reduce cost and LOS of AMI patients.

• 보건행정학회지
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• 제3권1호
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• pp.53-83
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• 1993

A small number of high cost patients usually spend a larger proportion of scarce health resources. Korea is no exception. Under the national health insurance, 12% of the insured persons have consumed approximately half of the national health insurance expenditures. Therefore, it is necessary to identify the characteristics of the high cost patient group, if we would like to reduce them. This study has defined high cost patients as those who have spent one and half million won and over per 6 months. The study reveals that high cost users are those who have a longer length of stays(LOS), 40days of LOS in the 6 months, have multiple admissions, 2 to 3 admissions per 6 months and are the elderly patients. They have spent 814.126won per on the average, and commonly suffered from malignant neoplasms, circulatory diseases, fracture, diabetes mellitus, etc. Unlike the case of western developed countries, early readmissions are not the major causes of high cost spending in Korea. Undoubtedly, a lengthy admission is the main cause of large spending. Health policies should vigorously be explored to respond appropriately. There are evidences that hospital beds are often misused. As the Korean health care system is lacking in a mechanism of patient evaluation under the fee-for-service remuneration system, an idea of progressive patient care needs to be tested. The Goverment should set up health policy to diversify the role of long-term care facilities and encourage people to establish them. Further studies are needed to identify factors influencing large medical bills necessary for formulating the health policy on cost containment.

• 대한전자공학회논문지TC
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• 제42권12호
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• pp.1-8
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• 2005

본 논문에서는 방송, 통신, 인터넷이 하나가 되는 BcN 환경에서 멀티캐스트 서비스를 위한 연결 수락 제어(Call Admission Control) 방안에 대하여 알아본다. 제한된 시스템의 처리 용량으로 인해 서비스 요청에 대하여 적절하게 연결 수락을 제어함으로써 QoS를 효과적으로 지원하는 것이 필요하다. 그 방법으로 하나의 멀티캐스트 서비스에 대하여 세 가지 등급으로 나누어, 각 등급마다 처리할 수 있는 역치(Threshold)를 정하여 제한된 역치 범위 안에서 서비스 요청을 수락할 수 있다. 특히, 시스템 입장에서 등급별 서비스 요청에 대하여 수락 및 거절함에 따른 이익(Reward)과 손실(Penalty)을 근거로 정의되는 시스템 cost 모델인 GAIN을 정의하여 최대한의 이득을 가져올 수 있는 역치의 범위를 정하고, 이를 근거로 서비스 요청을 제어한다. 성능 분석을 위하여 시스템을 M/M/m/m으로 모델링하여 다양한 환경에서 GAIN을 알아보고, 제안된 알고리즘의 효과를 보인다.

• 대한영양사협회학술지
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• 제5권1호
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• pp.48-53
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• 1999

This study was prospectively conducted to investigate any relationship of nutritional status at the time of admission to length of hospital stay and mortality. All patients admitted to the Asan Medical Center between October 13 and November 12, 1997 who met the study criteria were included in the study. Patients were classified as Not-at-risk, At-risk Ⅰ or At-risk Ⅱ based on the levels of serum albumin and total lymphocyte count in a computerized nutrition screening program. Sixty three percent of the patients were classified as Not-at-risk Group, 29% as At-risk Group Ⅰ and 8% as At-risk Group Ⅱ. Significant correlation was observed between nutritional status and LOS (P＜0.01) as well as mortality rate (P＜0.05). The more the patient had the nutritional risk factors, the longer the LOS and the higher the mortality rate were. Further studies have to be done in order to demonstrate cost-effectiveness of medical therapy for the malnourished hospitalized patients.

• Journal of Communications and Networks
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• 제16권2호
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• pp.130-139
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• 2014

Due to the unpredictable nature of channel availability, carrying delay-sensitive traffic in cognitive radio networks (CRNs) is very challenging. Spectrum leasing of radio resources has been proposed in the so called coordinated CRNs to improve the quality of service (QoS) experienced by secondary users (SUs). In this paper, the performance of coordinated CRNs under fixed-rate with hard-delay-constraints traffic is analyzed. For the adequate and fair performance comparison, call admission control strategies with fractional channel reservation to prioritize ongoing secondary calls over new ones are considered. Maximum Erlang capacity is obtained by optimizing the number of reserved channels. Numerical results reveal that system performance strongly depends on the value of the mean secondary service time relative to the mean primary service time. Additionally, numerical results show that, in CRNs without spectrum leasing, there exists a critical utilization factor of the primary resources from which it is not longer possible to guarantee the required QoS of SUs and, therefore, services with hard delay constraints cannot be even supported in CRNs. Thus, spectrum leasing can be essential for CRN operators to provide the QoS demanded by fixed-rate applications with hard delay constraints. Finally, the cost per capacity Erlang as function of both the utilization factor of the primary resources and the maximum allowed number of simultaneously rented channels is evaluated.

• 보건행정학회지
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• 제23권2호
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• pp.124-131
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• 2013

Background: This study aimed to measure the opportunity income by identifying the economic length of stay (ELOS) which is the intersection point of daily revenue and cost on appendectomy and pneumonia cases. Methods: The research subjects were 460 patients of appendectomy and 606 patients of pneumonia, discharged from a general hospital between July 1, 2009 and June 30, 2010. ELOS calculated with both of total revenue on diagnosis-related group (DRG) and fee-for service (FFS). The cost is calculated by activity-based costing system of the hospital. Results: Average length of stay (ALOS) of appendectomy was 4.48 days and its average revenue per case were 1,710,215 (1,989,105) won by DRG (FFS). The variable cost was 491,262 won which was 28.7% (24.7%) of DRG (FFS) total revenue. And 97.2% of the total variable cost was incurred within 2 days from admission. The ELOS was 4 (5) days in DRG (FFS). Shortening three days (two days) would increase opportunity income 52.0% (82.2%) in DRG (FFS). ALOS of pneumonia case was 4.86 days and its average revenue per case were 489,448 (761,426) won by DRG (FFS). The variable cost was 27,230 won which was 5.6% (3.6%) of DRG (FFS) total revenue. Thirty-eight point nine percent of the daily variable cost was incurred in discharge date. The ELOS was 2 (4) days in DRS (FFS). Shortening three days (one day) would increase opportunity income 27.6% (37.2%) in DRG (FFS). Conclusion: The ELOS would be used by strategic index for achieving minimum profit and developing the ways to get there. But we also should not pass over that the opportunity income obtained by the reducing ALOS may cause some problem of quality.

• Journal of Communications and Networks
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• 제18권5호
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• pp.806-817
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• 2016

Opportunistic routing (OR) has been proposed as a viable approach to improve the performance of wireless multihop networks with lossy links. However, the exponential growth of the bandwidth-sensitive mobile traffic (e.g., mobile video streaming and online gaming) poses a great challenge to the performance of OR in term of bandwidth guarantee. To solve this problem, a novel mechanism is proposed to opportunistically forwarding data packets and provide bandwidth guarantee for the bandwidth-sensitive traffic. The proposal exploits the broadcast characteristic of wireless transmission and reduces the negative effect of wireless lossy links. First, the expected available bandwidth (EAB) and the expected transmission cost (ETC) under OR are estimated based on the local available bandwidth, link delivery probability, forwarding candidates, and prioritization policy. Then, the policies for determining and prioritizing the forwarding candidates is devised by considering the bandwidth and transmission cost. Finally, bandwidth-aware routing algorithm is proposed to opportunistically delivery data packets; meanwhile, admission control is applied to admit or reject traffic flows for bandwidth guarantee. Extensive simulation results show that our proposal consistently outperforms other existing opportunistic routing schemes in providing performance guarantee.

• Archives of Plastic Surgery
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• 제35권2호
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• pp.223-228
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• 2008

Purpose: V.A.C. is a new concept which is closed dressing with negative pressure to promote wound healing. It has been widely used as the treatment of chronic and acute wounds such as pressure sores, burns, stasis ulcers, and other complicated wounds. However It has disadvantages such as high cost and the need of specific equipment. In this article, we described new method to overcome these disadvantages. Methods: We made newly innovated equipment with 50 cc syringe and spring to create negative pressure. From May 2006 to May 2007, we applied it to two patients with chronic wound. Results: The treatment period was 5 weeks for one case and 3 weeks for the other case. Both patients were healed completely without admission and wound healing was accelerated. During follow-ups, there were no complications. The mean cost for single dressing was 9,590 won. Conclusion: Modified portable negative therapy using newly innovated equipment could accelerate wound healing better than conventional dressing. It lowers the number of dressings, saves cost of treatment, and enables treatment as outpatient basis.

• 문화기술의 융합
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• 제2권2호
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• pp.51-63
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• 2016

본 연구는 관절병증질환자의 의료이용에 따른 의료비와 생산성손실비용 조사하고자 하였다. 본 연구를 위하여 2012년 한국의료패널 총 5,434가구, 15,872명을 이용하여 만19세 이상 관절병증질환자는 1,370명을 대상으로 하였다. 연구방법은 응급의료이용, 입원의료이용, 외래의료이용에 대한 평균의료이용횟수와 의료비를 구하였고, 연간관절병증 질환자의 응급생산성손실비용은 2012년 1일 평균임금 ${\times}$ N ${\times}$ 평균의료비를 곱하여 산출하였다. 연간응급 의료이용횟수는 1회, 의료비는 42,128,870원, 생산성손실비용은 98,640,000원이였다. 연간입원의료이용횟수는 4.79회, 의료비는 42,128,870원, 생산성손실비용은 945,036,820원이였다. 연간외래의료이용횟수는 12.7회, 의료비는 42,128,870원, 생산성손실비용은 91,252,728,000원이였다. 이상과 같은 결과를 바탕으로 다음과 같은 결론을 얻었다. 관절병증의 발생은 의료비증가와 생산성저하에 영향을 미칠 수 있으며 가구 및 환자에 있어 큰 부담이며 삶의 질도 저하될 것이다, 관절병증질환의 감소를 위한 운동 및 관리에 철저한 검토가 필요하다.