• 한국정보과학회논문지:시스템및이론
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• 제26권9호
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• pp.1135-1144
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• 1999

본 논문에서 우리는 셀룰러 통신 시스템을 위한 위치갱신과 위치질의 비용을 줄일 수 있는 새로운 위치관리 기법을 제안한다. 위치갱신 및 위치질의 비용을 줄이기 위하여, 제안한 위치관리 기법은 사용자 지역성을 사용한다. 사용자 지역성은 이동 지역성과 호 지역성으로 이루어진다. 이동 지역성을 갖는 이동단말들을 위한 위치갱신은 지역 PVLR(Proxy-Visitor Location Register) 갱신에 의해 위치갱신 비용을 줄일 수 있다. 호 지역성을 갖는 이동단말들을 위한 위치질의는 지역 PVLR 질의에 의해 위치질의 비용을 줄일 수 있다. 분석 모델을 통하여, 제안한 기법의 성능 분석과 IS-41 표준과 제안 기법과의 성능을 비교한다. 사용된 비교 척도는 네트워크 비용, 데이타베이스 비용 그리고 호 설정 지연이다. 이들 모든 척도들에 대해서, 제안 기법이 IS-41 표준에서 정의된 위치관리 기법보다 더 좋은 성능을 보인다. 또한 비교 결과는 CMR(Call-to-Mobility Ratio)에 상관없이 제안 기법이 IS-41 기법보다 성능이 좋음을 보여준다. Abstract In this paper, we propose a new location management scheme for cellular communication systems with the goal of reducing both location update and query cost. In order to reduce both location update and query cost, the proposed scheme uses user locality. User locality consists of movement and call locality. For mobile terminals with movement locality, location update cost is reduced by local PVLR(Proxy-Visitor Location Register) update. Location query cost is reduced by local PVLR query for mobile terminals with call locality. Through analytical models, we analyze the performance of the proposed scheme and compare it with that of the IS-41 scheme. The measures of comparison used are the network cost, the database cost, and the call set up delay. For all these measures, the proposed scheme performs better than the location management scheme defined in the IS-41 standard. Result comparison also shows that the our scheme performs better than the IS-41 scheme, regardless of CMR(Call-to-Mobility Ratio).

• 대한영양사협회학술지
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• 제9권1호
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• pp.32-39
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• 2003

Although medical nutrition therapy (MNT) is considered as a cornerstone of medical treatment for hypercholesterolemia, few studies have evaluated medical and economical outcome of MNT. This study was conducted to identify whether MNT administered by registered dieticians could lead to a beneficial clinical and cost outcome in persons with hypercholesterolemia. A prospective clinical trial was carried out at outpatient clinics, which involved an initial visit with a dietitian followed by another visit at first 4 weeks during the 6 weeks study periods. Thirty-nine subjects took part in a 6 weeks nutrition intervention program. Clinical and economical outcomes were compared before and after MNT. Medical nutrition therapy lowered total serum cholesterol level 6.1% (P<0.05), low-density lipoprotein cholesterol (LDL-C) 9.4% (P<0.05) and high-density lipoprotein cholesterol (HDL-C) 3.0% (P<0.05). The cost-effective ratio was ￦ 1,520/cholesterol mg/dl and ￦ 1,441/LDL-cholesterol mg/dl, respectively. After dietitian's intervention, lipid drug eligibility was obviated in 16 of 39(41%) subjects. The cost savings from the avoidance of lipid medications was ￦ 151,107 per patient annually. In conclusion, it is suggested that provision of systemic intensive nutritional care for persons with hypercholesterolemia has significant effects on serum cholesterol reduction and clinical cost savings.

• 동아시아식생활학회지
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• 제20권5호
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• pp.823-835
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• 2010

The research aimed to measure the efficiency of using multi stores in a foodservice company using by DEA (data envelopment analysis) which is a new management science technique. The study also attempted to identify relevant variables affecting DEA efficiency in order to suggest methods for improving efficiency. The data were collected from 148 contract foodservice operations, which were operated in similar fashion in October 2009. The DEA efficiency was calculated as an output-oriented BCC Model. Sales, and CSI (customer satisfaction index) were used as output variables whereas food cost, labor cost, and management expense were used as input variables to calculate the DEA efficiency. Operation process variables of the unit consisted of the were consist of ratio of regular employee, ratio of housekeeper, meal counts, meal price, food cost per meal, contract period, number of menu items, forecasting accuracy, order accuracy, inventory turnover, use of processed food, deviation of food cost, number of new menus, and number of events. According to the BCC score and profitability, units were classified into four groups: High efficiency-high profitability (HEHP), High efficiency-low profitability (HELP), Low efficiency-high profitability (LEHP), and Low efficiency-low profitability (LELP). The HEHP group contained 54 units, which mostly contracted management fee type and had a high meal price. The units were also very large and, served three meals. Twenty of the units were operated with high labor cost: most of these were factories and hospitals. The LEHP group contained 20 units, that were mainly office stores of large scale and medium price. Fifty-four LELP group had a low meal price. A high performance group must have high efficiency, profitability, and satisfaction. The BCC score was over 0.969, the meal price was over 4,116 won, the food cost was over 2,077 won, and meal counts per month were over 10,212 meals.

• 한국도로학회논문집
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• 제11권1호
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• pp.59-67
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• 2009

센싱 기술의 발달로 다양한 종류의 매체를 이용한 우수한 차량 검지장비들이 개발되고 있는 요즘, 간단한 구조의 저가형 검지장비 또한 적은 예산으로 여러 곳에 설치할 수 있다는 장점 때문에 지속적인 연구가 이루어지고 있다. 본 연구에서는 저가형 차량 검지장비로서 센서를 사선으로 설치하여 좌우 및 전후 바퀴의 통과시간 간격과 차량의 윤거값을 적용하여 차량속도를 추정하는 방법을 제안하였다. 출고된 차량의 제원조사에서 얻어진 대표 윤거값을 축거와 뒤윤거의 비율에 따라 소형과 대형 차량으로 구분하여 적용하므로 기존의 연구보다 정확한 속도추정이 가능하도록 개선하였다. 특히, 소형과 대형차량을 구분하는 파라미터를 통하여 조사지점의 차종구성 비율을 고려한 정확도 보정이 가능하다. 간단하고 저가로 개발된 본 연구의 사선형 센서를 이용한 검지장비는 적은 비용으로 교통상황을 설명하는데 효율적으로 활용될 것으로 기대된다.

• 한국산업보건학회지
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• 제29권1호
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• pp.57-68
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• 2019

Objective: The purpose of this study is to propose the benefits of reduction measures according to the occupational radon reference level in order to present basic data for radon management guidelines considering domestic circumstances. Methods: This study uses radon data measured in the subway stations from 2015 to 2016. Of the total of 4,643 cases, 4,231 cases were analyzed excluding the 412 cases where the values were below $300Bq/m^3$. Results: Cost-Benefit analysis was done on the results of the field survey on subway work sites. At the exposure level of $400Bq/m^3$, the ratio between the cost and the benefit was highest at 1 : 1.81(the cost was KRW 1,398,568,032, while the benefit KRW 2,5248,772,841). At the exposure level of $600Bq/m^3$, the ratio of cost and benefit was 1: 1.80, at $300Bq/m^3$ it was 1.72, at $800Bq/m^3$ it was 1.71, at $200Bq/m^3$ it was 1.54, and at $100Bq/m^3$ it was 1.40. Conclusions: Radon management in the workplace provides economic benefits and appropriate reduction strategies are needed. In addition, it is necessary to establish and distribute radon exposure assessment procedures and guidelines for the safety and health of employees when exceeding the exposure standard, and guidelines for radon management in the workplace should be established.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.965-965
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• 1995

• 한국세라믹학회지
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• 제51권5호
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• pp.380-385
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• 2014

Clay-based membranes with submicron pore size were successfully prepared by a simple pressing process using low-cost starting materials(e.g., kaolin (K), bentonite (B), talc (T), and sodium borate). The green bodies were sintered at $1000^{\circ}C$ for 2 h in air. The effect of clay-mineral composition on the flexural strength of clay-based membranes was investigated. The porosity of the clay-based membranes could be controlled within the range of 34 - 42% by adjusting the starting composition. The flexural strength of the low-cost membranes depended on both the porosity and the ${\alpha}$-quartz content. In turn, the porosity and ${\alpha}$-quartz content were affected by the (B+T) /(K+B+T) ratio. The plot of strength relative to this ratio, showed a maximum when the ratio was 0.4. The typical flexural strength of these clay-based membranes (with ratio 0.4) was 28 MPa at 34% porosity.

• 상하수도학회지
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• 제31권3호
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• pp.237-248
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• 2017

The estimation method of economical leakage management target utilized upon planning business for improvement of revenue water ratio in South Korea is presented and applicability of methods developed in this study is assessed through application on site. With a consideration of revenue water ratio in application target area, estimation method of long-term economical leakage management target is applied. Three leakage reduction methods such as replacement of residual aged pipe, leakage investigation and restoration and water pressure management are applied with a consideration of characteristics of site. Due to difficulty of obtaining data, analysis of cost/benefit by leakage reduction methods is performed by applying method of leakages estimation equation among statistical methods. As a result of application, revenue water ratio corresponding to long-term economical leakage management target is 91.6 %.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.717-724
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• 2003

Although sand compaction pile is applied considerably for increase of hearing capacity in domestic, it is getting more necessary to develope the alternative materials because of exhaustion and increase of unit cost of sand. In this study, stress concentration ratio between crushed-stone pile and soft ground was measured and, a displacement ratio 30, 40 and 50%, variation of stress concentration ratio was analyzed. As an increase displacement ratio, the stress concentration effect of crushed-stone compaction pile doesn't increase proportionally and effect of ground improvement in case of ground was good at displacement ratio 30% or 40%. The stress concentration ratio of crushed-stone compaction pile in group piles is 1.5 times that of crushed-stone compaction pile in single pile.

• 한국융합학회논문지
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• 제8권2호
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• pp.163-168
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• 2017

기존의 공공사업 타당성 평가는 경제성분석을 위주로 추진되었으나, 계층분석법(AHP: Analytic Hierarchy Process)을 도입하면서 정책성, 지역균형발전, 기술성 등의 항목이 추가로 평가되고 있다. 이 연구는 최근 3년간 건설사업과 연구개발사업의 예비타당성조사 데이터를 분석하고, 비용편익비(Cost-Benefit Ratio)와 계층분석의 가중치(weight) 간의 상관관계 분석을 통해 상호 관련성을 검증하고자 한다. 연구결과 비용편익비와 AHP 가중치의 상관관계가 건설사업의 경우 0.744, 연구개발사업의 경우 0.899로 나타났다. 즉, 사업시행 여부를 결정하는 AHP 결과가 비용편익분석 결과에 의해 크게 좌우됨으로, 경제성 위주의 평가를 보완하기 위해 도입된 AHP가 당초 기대와는 달리 종합적 분석의 역할을 충분히 수행하지 못하고 있다. 따라서 AHP 분석의 효과를 극대화 할 수 있는 다양한 연구설계가 지속적으로 논의될 필요가 있다.