Earticle

본 연구에서는 소프트웨어 제품을 개발하여 테스팅을 거친 후 사용자에게 인도하는 시기를 결정하는 방출문 제에 대하여 연구 하였다. 소프트웨어의 결함을 제거하거나 수정 작업과정에서 유한고장수를 가진 비동질적인 포아송 과정에 기초하였다. 수명강도는 다양한 형상모수와 척도모수에 이용 할 수 있기 때문에 신뢰성 분야에서 많이 사용되 는 비선형 특성을 가진 반-로지스틱 분포 모형을 이용한 방출시기에 관한 문제를 제시하였다. 소프트웨어 요구 신뢰 도를 만족시키고 소프트웨어 개발 및 유지 총비용을 최소화 시키는 최적 소프트웨어 방출 정책에 대하여 논의 되었 다. 본 논문의 수치적인 예에서는 고장 시간 자료를 적용하였으며 모수추정 방법은 최우추정법을 이용하고 최적 방 출시기를 추정하였다. 따라서 소프트웨어 방출시기를 사전 정보로 활용하면 잠재적 보안피해액을 줄 일 수 있다고 판단된다.

In this paper, make a study decision problem called an optimal release policies after testing a software system in development phase and transfer it to the user. When correcting or modifying the software, finite failure non-homogeneous Poisson process model, presented and propose release policies of the life distribution, half-logistic property model which used to an area of reliability because of various shape and scale parameter. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. In a numerical example, the parameters estimation using maximum likelihood estimation of failure time data, make out estimating software optimal release time. Software release time is used as prior information, potential security damages should be reduced.

Purpose: This study was to identify the effectiveness of high-intensity laser therapy on pain and function of a frozen shoulder. Methods: Thirty patients were assigned to two groups: the experimental group (n=15) and the control group (n=15). Both groups received traditional therapy for 4 weeks, 3 days a week. The experimental group, however, received an additional high intensity laser therapy. Pain was measured using the visual analogue scale (VAS). The functional ability was measured using the patient specific functional scale (PSFS). A paired t-test was used to determine any differences before and after the treatment, and an independent t-test was used to determine any differences between treatment groups. Results: Both groups showed a statistically significant difference for VAS and PSFS score (p<0.05). In comparison between two groups, more experimental group than control group statistically significant difference (p<0.05). Conclusion: There seems to be a positive effect on pain and function of frozen shoulder from using high intensity laser therapy.

Objective: This study was conducted to investigate the effect of high-intensity laser therapy(HILT), transcutaneous electrical nerve stimulation(TENS), and ultrasound(US) treatment on pain, grip strength, and hand function in patients who had undergone carpal tunnel syndrome surgery. Design: A randomized controlled trial. Methods: Thirty patients who had undergone carpal tunnel syndrome surgery were randomly assigned to receive either TENS combined with HILT, US combined with HILT, or only HILT as the control group. Treatments were applied around the surgical site, and pre- and post-treatment changes were evaluated. Pain was assessed using NPRS, hand symptoms using CTS-6 and BCTQ-SSS, grip strength with an electronic dynamometer, and hand function using BCTQ-FSS. Treatments were administered seven times over two weeks. Results: The pain and symptoms were significantly reduced(p<0.05) and grip strength and hand function were significantly increased(p<0.05) after treatment compared to before treatment for all subjects. Pain was significantly reduced(p<0.05) and grip strength was significantly increased(p<0.05) in the TESN+HILT group and US+HILT group compared to the Control group. Hand symptoms were significantly reduced(p<0.05) and hand function significantly increased(p<0.05) in the TENS+HILT group compared to the Control group. Conclusions: TENS combined with HILT was found to be more effective than US combined with HILT in reducing pain and symptoms and improving grip strength and hand function in patients following carpal tunnel syndrome surgery. These findings suggest that these treatment modalities can be beneficially applied in clinical practice.

We wanted to find the intensity of exercise that could increase brainderived neurotrophic factor (BDNF) expression and improve spatial learning and memory without dietary control. C57BL/6 mice were fed a 60% high-fat diet (HFD) for 6 weeks to induce obesity. Obesity-induced mice were exercised on a treadmill for 8 weeks at various exercise intensities: HFD-control (n= 7), HFD-low-intensity exercise (HFD-LIE, n= 7, 12 m/min for 75 min), HFD-middle intensity exercise (HFD-MIE, n= 7, 15 m/min for 60 min) and HFD-high-intensity exercise (HFD-HIE, n= 7, 18 m/min for 50 min). One week before sacrificing mice, the Morris water maze test was performed, and the hippocampus was immediately removed after sacrifice. The expression levels of BDNF (encoded by the gene Bdnf) and tropomyosin receptor kinase B (TrkB) in the hippocampus were analyzed by quantitative real-time reverse transcriptionpolymerase chain reaction and western blot. In the last probe test of the Morris water maze test, occupancy in the target quadrant was significantly higher in the HFD-HIE group (P< 0.05) than in the other groups. In addition, mRNA expression from the Bdnf promoter region was found to be significantly higher in the HFD-HIE group than in the other groups (P< 0.001). Although there were some differences in the levels of significance, the expression levels of both BDNF and TrkB were significantly higher in the HFD-HIE group than in the other groups. Therefore, relatively high-intensity aerobic exercise can resist the adverse effects of a high-fat diet on the brain without dietary control.

Effects of aerobic exercise intensity on Brain-derived neurotrophic factor (BDNF) expression of hippocampus and cognitive function in mice with high-fat diet are not well known. In this study, we investigated the differences in hippocampus BDNF and its receptor, tyrosine kinase B (TrkB) expression and cognitive functions in high-fat diet-fed mice after aerobic exercise with different intensities. The mice were fed a 60% high-fat diet for 6 weeks and divided into 4 experimental groups; no exercise (HFD, n=6), low intensity exercise (HFD-LE, n=6), moderate intensity exercise (HFD-ME, n=6), or high intensity exercise (HFD-HE, n=6). Exercise intervention was conducted for 8 weeks. For the control group (CON, n=6), normal diet was fed for 14 weeks. Protein expression of BDNF and TrkB were measured by western blot and cognitive functions were determined by T-maze task and Morris water maze task. Our result show that HFD-HE and HFD-LE groups had significantly higher BDNF protein expression level than CON, and HFD-HE group had significantly higher than HFD-LE group. The HFD-HE group also showed significantly higher TrkB protein expression level than all other groups. In the T-maze task, novel route awareness was significantly higher in HFD-HE and HFD-LE groups than CON. For Morris water maze task, time to reach platform was significantly shorter in HFD-HE than all other groups. These results indicate that high intensity exercise is generally more effective for increases in BDNF and TrkB protein expression and improvements on cognitive functions than moderate and low intensity exercise even with high fat diet. Therefore, we hypothesize that high intensity exercise can be recommended to overweight or obese individuals with reduced cognitive function.

Software reliability in the software development process is an important issue. In infinite failure non-homogeneous Poisson process software reliability models, the failure occurrence rates per fault. can be presented constant, monotonic increasing or monotonic decreasing pattern. In this paper, the reliability software cost model considering decreasing intensity function was studied in the software product testing process. The decreasing intensity function that can be widely used in the field of reliability using power law process, log-linear processes and Musal-Okumoto process were studied and the parameter estimation method was used for maximum likelihood estimation. In this paper, from the software model analysis, we was compared by applying a software failure interval failure data considering the decreasing intensity function The decreasing intensity function model is also efficient in terms of reliability in the arena of the conservative model can be used as an alternating model can be established. From this paper, the software developers have to consider life distribution by preceding information of the software to classify failure modes which can be gifted to support.

In this study, we was compared the reliability performance of the software reliability model, which applied the Goel-Okumoto model developed using the exponential distribution, to the logarithmic function modifying the intensity function and the Rayleigh form. As a result, the log-type model is relatively smaller in the mean squared error compared to the Rayleigh model and the Goel-Okumoto model. The logarithmic model is more efficient because of the determination coefficient is relatively higher than the Goel-Okumoto model. The estimated determination coefficient of the proposed model was estimated to be more than 80% which is a useful model in the field of software reliability. Reliability has been shown to be relatively higher in the log-type model than the Rayleigh model and the Goel-Okumoto model as the mission time has elapsed. Through this study, software designer and users can identify the software failure characteristics using mean square error, decision coefficient. The confidence interval can be used as a basic guideline when applying the intensity function that reflects the characteristics of the lifetime distribution.

유한고장수를 가진 비동질적인 포아송 과정에 기초한 모형들에서 잔존 결함 1개당 고장 발생률(강도함수)은 일반적으로 상수, 혹은 단조증가 및 단조 감소 추세를 가지고 있다. 본 논문에서는 기존의 소프트웨어 신뢰성 모형인 Goel-Okumoto 모형 강도함수를 재조명하고 이 분야에 적용 될수 있는 보다 넓은 왜도와 첨도를 가지는 Burr모형 강도 함수 및 의료정보분야 및 여러 분야에서 널리 사용되는 2모수 카파(Kappa(2)) 분포 모형 강도함수를 제안하여 비교하고자 한다. 수치적인 예에서는 고장 간격시간으로 구성된 NTDS(Naval Tactical Data System)자료를 이용하였고 모수추정 방법은 최우추정법과 일반적인 수치해석 방법인 이분법을 사용하여 모수 추정을 실시하였다. 그리고 모형 설정과 선택 판단기준은 편차 자승합을 이용한 적합도 검정이 사용되었다

Finite failure NHP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault (intensity In this paper, intensity function of Goel-Okumoto model was reviewed, proposes Kappa (2) and the Burr distribution, which maked out efficiency application for software Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method. For model determination and selection, ex-plored goodness of fit (the error sum of squares) The methodology developed in this paper is exem-plified with a software reliability real data set introduced by NTDS (Naval Tactical Data System

PURPOSE: The purpose of this study was to find out the treatment patterns of Children with cerebral palsy, and to analyze the effect of physical function level and treatment intensity on improvement of physical function in children with cerebral palsy for six months. METHODS: Participants were 126 children (boys 83, girls 43) diagnosed cerebral palsy that the mean age was at 33months, ranged from 8 months to 77 months. We collected data related on demography and disable characteristic, treatment pattern using by questionnaire constructed ourselves for six months on caregivers. The treatment pattern includes, type, frequency, and institute of treatment. We performed the evaluation of Gross Motor Function Measurement (GMFM) and Pediatric Evaluation of Disability Inventory (PEDI) between pre and post for six months in order to find out improvement of physical function. We analyzed the effect of physical functional level measured by Gross Motor Functional Classification system, age, treatment intensity on physical function using by repeated measures ANOVA for SPSS PC ver. 22.0. RESULTS: The average of treatment frequency for physical therapy was 5.74 times per week, occupational therapy was 3.96 times, speech therapy was 2.96 times, treatment for accompanying disability was 3.12 times. Physical function level and age was significantly factors affecting improvement of physical function, there was no significant difference according to treatment intensity. CONCLUSION: We suggest that physical function and age might be important factors on improvement of physical function and professional rehabilitation team must consider the appropriate treatment type customized to each children.

본 연구는 고강도 저항운동시 복어 추출물 섭취가 항산화효소와 간기능 지표에 미치는 영향을 규명하고자 하는 것이다. 이를 위하여 20대 남자 대학생 18명을 복어 추출물 섭취군 9명과 비 섭취군 9명을 나누어 2주 동안 1RM의 80% 고강도 저항운동을 적용하면서 항산화효소 측정항목인 GPX(glutathione peroxidase), SOD(superoxide dismutase) 및 간기능 지표인 AST(aspartate aminotransferase), ALT(alanine aminotransferase)를 측정하여 다음과 같은 결과를 얻었다. 항산화효소에서는 복어추출물 섭취에 따른 유의한 변화를 확인할 수 없었으나, 간기능 지표 인 혈청 AST와 ALT의 변화에서는 복어 추출물 섭취군이 적용 전에 비해 적용 후에 유의하게 낮게 나타났다(p<.05). 본 연구를 통해 고강도 저항운동시 복어 추출물 섭취가 간 기능 지표인 혈청 AST와 ALT 감소에 도움이 되는 것을 확인 하였다.

The purpose of this study was to evaluate the effect of a puffer fish extract intake on antioxidant enzyme and liver function indicator during high-intensity resistance exercise. The subjects for the study were 18 male university student composed of the puffer fish extract group(n=9), control group(n=9), which trained for 2 weeks high-intensity resistance exercise. Glutathione peroxidase(GPX), Superoxide dismutase(SOD) and Aspartate aminotransferase(AST), Alanine aminotransferase(ALT) measured in all the subjects after the end of the 2 weeks high-intensity resistance exercise. The findings of this study were as follows; The puffer fish extract group was significantly lower serum AST and ALT. Consequently, Puffer fish extract intake during high-intensity resistance exercise will be effectively appeared to decreasing liver function indicator such as serum AST and ALT.

국내에서 수공구조물의 설계를 위한 확률강우량을 산정하기 위해서 널리 사용되는 강우강도식은 주로 회귀분석을 적용한 형태가 일반적이지만, 본 연구에서는 각 지점별 적정확률분포형의 누가분포함수를 활용하여 강우강도식의 형태를 결정하고, 매개변수는 유전자알고리즘을 적용하여 추정하는 강우강도식을 제안하고자 한다. 기존에 사용하던 강우강도식과의 정확도 비교를 위하여 기상청 22개 지점에 대한 재현기간, 지속기간별 평균제곱근오차, 평균제곱근 상대오차를 검토한 결과 누가분포함수를 활용한 강우강도식이 더 높은 정확도를 가짐을 보였으며, 또한, 최근의 집중호우에 대한 영향을 살펴보기 위하여 2006년 까지의 강우자료를 이용하여 기존의 회귀식에 의한 방법과 누가분포함수를 활용한 경우의 결과값을 비교한 결과 이 경우에도 누가분포함수를 활용한 강우강도식의 정확도가 더 높음을 알 수 있었다. 결과적으로 본 연구에서 제안된 누가분포함수를 활용한 강우강도식은 기존의 회귀분석을 활용한 강우강도식보다 정확도면에서 우수하다고 할 수 있으며, 국내에 충분히 적용가능한 형태의 강우강도식이라고 판단된다.

Intensity-Duration-Frequency (IDF) curve that is essential to calculate rainfall quantiles for designing hydraulic structures in Korea is generally formulated by regression analysis. In this study, IDF curve derived by the cumulative distribution function ("IDF by CDF") of the proper probability distribution function (PDF) of each site is suggested, and the corresponding parameters of IDF curve are computed using genetic algorithm (GA). For this purpose, IDF by CDF and the conventional IDF derived by regression analysis ("IDF by REG") were computed for 22 Korea Meteorological Administration (KMA) rainfall recording sites. Comparisons of RMSE (root mean squared error) and RRMSE (Relative RMSE) of rainfall intensities computed from IDF by CDF and IDF by REG show that IDF by CDF is more accurate than IDF by REG. In order to accommodate the effect of the recent intensive rainfall of Korea, the rainfall intensities computed by the two IDF curves are compared with that by at-site frequency analysis using the rainfall data recorded by 2006, and the result from IDF by CDF show the better performance than that from IDF by REG. As a result, it can be said that the suggested IDF by CDF curve would be the more efficient IDF curve than that computed by regression analysis and could be applied for Korean rainfall data.

The purpose of this study was to investigate the effect of different resistance exercise intensity on circulatory(heart rate, blood pressure) and vascular function(PGI2, ET-1). Twelve male subjects(age 42.7±4.91years, weight 75.8±5.82kg) were randomly assigned to high and low resistance exercise treatment by crossover design. The high resistance exercise treatment performed three sets at 5-7RM with 2min rest between sets and the low resistance exercise treatment performed three sets at 10-13RM with 2min rest. Resistance exercise composed of seated bench press, barbell shoulder press, pull down, back extension, sit up, leg curl, leg press, calf raise. Venous blood samples were taken from an antecubital vein by venipuncture at pre-exercise, recovery period(60minutes later immediately after exercise). Systolic blood pressure was significantly decreased by high intensity exercise at recovery period, but low intensity exercise did not induce any significant change. PGI2 was significantly increased by both high and low intensity resistance exercise but there are any significant change with different exercise intensity.

본 연구의 목적은 혈류제한 요법과 저-강도 저항운동의 적용 후 관절염의 치료를 위해 골 연골 재생술을 받은 중년 여성의 슬관절 신전 근력, 균형, 기능 및 관절염 지수에 미치는 효과를 검증하는데 있다. 연구 대상자는 45-65세 중년 여성 중 관절염의 치료를 위해 골연골 재생술을 받은 22명을 모집해 혈류제한 요법과 저-강도 저항운동을 시행한 집단 (BG, n=11)과 저-강도 저항 운동만 시행한 대조군(CG, n= 11)으로 나누어 8주간 주 2회 중재를 시행한 후 슬관절 신전 근력의 최대 수의적 등척성 근력, 균형, 기능 및 관절염 지수를 평가하였다. 연구결과는 두 집단 모두 중재 후 모든 변인이 개선되었으며, BG의 경우 CG와 비교해 슬관절 신전 근력과 기능에서 더 효과적인 것을 확인하였다. 따라서, 골연골 재생 술을 받은 중년 여성에게 혈류 재한 요법과 저-강도 저항 운동은 효과적으로 슬관절 신전 근력, 균형, 기능 및 관절염 지수 를 개선시킴으로 재활 운동 프로그램에 포함하는 것을 권장한다.

The aim of this study was to evaluate the effects of the blood flow restriction (BFR) method and low-intensity resistance exercise on knee extension strength, balance, function, and osteoarthritis (OA) index in middle-aged women who had undergone osteochondral regeneration surgery for the treatment of OA. The participants were 22 middle-aged women aged 45-65 who had undergone osteochondral regeneration surgery for OA and were divided into a group that underwent the BFR method and low-intensity resistance exercise (BG, n = 11) and a control group (CG, n = 11). After performing the intervention twice a week for 8 weeks, maximum voluntary isometric contraction of knee extension strength, balance, function and OA index were assessed. The results of the study showed that all variables improved after the intervention in both groups and that BG was more effective in knee extension strength and function compared to CG. Therefore, it is recommended that middle-aged women who have undergone osteochondral regeneration surgery include the BFR method and low-intensity resistance exercise in their rehabilitation exercise programme, as they effectively improve knee extension strength, balance, function and OA index.

본 연구는 운전 중 발생하는 청각 자극의 유형 및 정도가 운전자가 지각하는 주관적 속도감에 어떠한 영향을 미치는지를 알아보고자 수행되었다. 본 연구에서 사용된 청각 자극은 엔진 소음과 음악 소리였으며 전자는 자동차의 속도에 따라 함께 변하는 청각 단서인 반면 후자는 자동차의 속도와는 무관하게 변화하는 비단서 소음으로 사용되었다. 엔진 소음의 강도만 조작되어 제시된 실험 1에서는 엔진 소음의 크기에 따라 운전자가 느끼는 주관적 속도감이 다르게 나타나 운전자들은 엔진 소음이 작을수록 기준속도보다 더 빨리 주행한 반면 엔진 소음이 클수록 더 천천히 주행하는 것이 관찰되었다. 실험 2에서는 엔진 소음과 음악 소리를 모두 들려주었는데, 그 결과 엔진 소음의 크기변화에 따른 주관적 속도감의 차이는 여전히 나타났으나 음악 소리의 크기변화에 따른 속도감의 차이는 보이지 않았다. 또한 실험 1과 2를 통합하여 음악 소리의 유무효과를 분석해 본 결과 음악 소리가 엔진 소음을 차폐시킬 만큼 크고 엔진 소음이 작을 경우에는 음악 소리가 없는 경우보다 속도를 더 내는 것으로 나타났다. 이는 음악 소리가 속도감에 영향을 주는 직접요인은 아니지만 간접적으로 영향을 미친다는 가능성을 시사한다.

The purpose of the present study was to investigate the effects of in-vehicle noise types and levels of intensity on drivers' driving speed estimation. Noise generated from the vehicle engine and musical sound sampled from the Korean pop were employed as the types of in-vehicle noise and their levels of intensity were systematically manipulated. In experiment 1 where the effect of the engine noise levels on speed estimation was observed, drivers showed the tendencies of driving faster than the targets speeds under lower noise intensity condition whereas driving slower under higher noise intensity condition. In experiment 2 where both musical sample and the engine noise were provided, drivers' subjective speed estimation was affected by the engine noise as revealed experiment 1, but not by musical sample. When the data from the both experiments were combined and analyzed, an interacting effect of engine noise levels and music sample levels was found: if the intensity of music sample was enough to overwhelm the engine noise, the drivers drove faster than lower engine noise level condition in the experiment 1. This result indicates that although the music sample is not the direct auditory cue of speed estimation as observed in the experiment 2, intense level of music sample can affect drivers' speed estimation when it is coupled with the lower engine noise level.

Purpose: This study examined the effects of high-intensity laser therapy (HILT) as a monotherapy on pain, knee function, and Borg Rating of Perceived Exertion (RPE) scores in a patient diagnosed with a meniscus tear Methods: A 64-year-old male patient was diagnosed with a meniscus tear, and a single-case A-B-A’ study design was applied. The study was conducted for six weeks and consisted of three phases: a one-week baseline phase (Phase A), a two-week intervention phase (Phase B), and a three-week follow-up phase (Phase A’). In the follow-up phase, after two weeks of observation, the final assessments were conducted during the last week. In the intervention phase, HILT was applied around the joint line of the affected knee three times per week (six times in total). The outcome measures included the Visual Analogue Scale (VAS), pressure pain threshold (PPT), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Borg Rating of Perceived Exertion (Borg RPE) scale. Results: Positive improvements were noted in all the outcome measures after HILT application. The VAS score was decreased by 5.5 points during movement and by 6.0 points in the standing position compared with the baseline, indicating significant pain relief. The PPT values increased at all measurement sites, with the most significant improvement observed in the quadriceps femoris muscle. The knee function was improved across all KOOS subdomains. In particular, the Quality of Life (QoL) showed the most significant change with a score of 18.7 points. The Borg RPE level decreased significantly from Borg 6 (‘Very hard’) at the baseline to Borg 1 (‘Very light’) post-intervention. In the follow-up phase (A’), although a regression pattern was observed in some outcome measures, significant improvements compared to the baseline were maintained, indicating the sustained effects of the intervention. Conclusion: HILT applied to a patient with a meniscus tear was effective in reducing pain and improving knee function. The therapeutic effects were maintained even after the intervention ended. Therefore, HILT can be used in clinical practice as a non-invasive conservative treatment for patients with meniscus tears.

In this paper we are concered with the counting processes with intersity function $g_n(t)$, where $g_n(t)$ not only depends on t but n. It is shown that under certain conditions the number of events in [0, t] follows a generalizes Poisson distribution. A counting process is also provided such that $g_i(t)$$\neq$$g_i(t)$ for i$\neq$j and the number of events in [0, t] has a transformed geometric distribution.

Engineering systems are usually repairable. The reliability of a repairable system can be represented by failure intensity function. A type of shape of failure intensity function is called a failure pattern. Reliability-Centred Maintenance (RCM) presents six typical failure patterns but its definition is unclear. It is an open issue how to recognize the failure pattern of repairable systems. This paper first discusses the problems of RCM with the notion of failure pattern; then presents the method for failure pattern recognition; and finally proposes a flexible failure intensity function model. The appropriateness of the model is illustrated by a real-world example.

One-dimensional approach to two-dimensional warranty data involves modeling us- age as a function of time. Iskandar (1993) suggests a simple linear model for usage. However, simple linear form of intensity function is of limited value to model the situa-tion where the intensity varies over time. In this study Weibull intensity is considered where the scale parameter is expressed in terms of different models. We will nd out how each parameter in the model a ects the warranty cost and which model gives a bigger number of failures within the two-dimensional warranty region.

Purpose: This study was undertaken to determine the parotid gland tolerance dose levels following intensity modulated radiation therapy (IMRT) for treating patients who suffered with head and neck cancer. Materials and Methods: From February 2003 through June 2004, 34 head and neck patients with 6 months of follow-up were evaluated for xerostomia after being treated by IMRT. Their median age was 59 years (range: 29～78). Xerostomia was assessed using a 4-question xerostomia questionnaire score (XQS) and a test for the salivary flow rates (unstimulated and stimulated: USFR and SSFR, respectively). The patients were also given a validated LENT SOMA scale (LSS) questionnaire. Evaluations were performed before IMRT and at 1, 3 and 6 months after IMRT. Results: All 34 patients showed significant changes in the XQS, LSS and Salivary Flow rates (USFR and SSFR) after IMRT. No significant changes in the XQS or LSS were noted in 12 patients who received a total parotid mean dose of ≤3,100 cGy at 1, 3 and 6 months post-IMRT relative to the baseline values. However, for the 22 patients who received ＞3,100 cGy, significant increases in the XQS and LSS were observed. The USFR and SSFR from the parotid glands in 7 patients who received ≤2,750 cGy were significantly preserved at up to 6 months after IMRT. However, the USFR and SSFR in 27 patients who were treated with ＞2,750 cGy were significantly lower than the baseline values at all times after IMRT. Conclusion: We suggest that the total parotid mean dose should be limited to ≤2,750 cGy to preserve the USFR and SSFR and so improve the subsequent quality of life. (Cancer Res Treat. 2006;38:84-91)