• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.87-93
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• 2017

This paper investigates active noise control of tower-type air conditioners using the filtered-x least mean square (FXLMS) algorithm to reduce fan blower noise transmission. Firstly, the main components required for the active control system including the error sensor, the control speaker and the reference sensors are selected. Since the noise could significantly reduce if the reference signal includes every frequency response information, a various reference signals from accelerometers and a microphone are used. Secondly, the controller based on the FXLMS algorithm with a single-channel reference signal is implemented. Then, the control performance is examined experimentally for the different reference signals. It is found that the accelerometer signal well possesses the motor vibration related noise and a microphone signal could includes global noise. When using the reference signal with a microphone located near the motor and the fan blower, the active control system reduces the noise globally, except for several peaks.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.923-928
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• 2008

Pyrotechnic shock or pyroshock is characterized as a transient vibration phenomenon which shows large acceleration and high frequency range up to 10kHz during the operation of separation devices where explosives are used. During the flight of a launch vehicle, pyroshock is mainly generated at several events such as satellite separation, fairing separation and stage separation. In this paper, wiremesh isolators are introduced and several types of isolators are manufactured for the performance tests. For the investigation of typical characteristics of wiremesh isolators, compressive loading tests are basically performed and pyroshock tests are accomplished to confirm pyroshock isolation ability of each wiremesh isolator by using 4Kg dummy mass.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1034-1043
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• 2006

The purpose of this study was to investigate the difference of the visual evaluation about gathered skirts according to different gathering conditions and objects. The experiment is made of factorial design for three variables-fabric(cotton, wool, polyester), ratio of gathers(1.5T, 2.0T, 2.5T), objects(real thing, 2D digital picture, 3D shape). Questionnaire consists of 33 sematic differential scale expressing gathered skirts' image. The subjects were 50 male and female students majoring in clothing and textile. The data were analyzed by Frequency, Factor analysis, Anova, scheffe's test. The results obtained were summarized as follows; 1. As the open-ended response there were difference among the image according to different gathering conditions and obects. 2. The image of gathered skirts was composed of 6 factors; activities, attraction, attention, softness, moderateness, function. 3. For visual evaluation of gathering conditions as different objects, there were similar as softly in fabrics and lager in ratio of gathers. 4. For visual evaluation of different objects as gathering conditions, there was more difference effect of ratio of gathers than fabrics.

• Environmental Analysis Health and Toxicology
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• v.24 no.3
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• pp.231-240
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• 2009

We explored collective behaviors of indicator species to elucidate the effect of the chemical stress. After the treatments of an insecticide, diazinon, at low concentrations (1.0 and 10.0 ${\mu}g/L$), spatial dispersion patterns of Daphnia magna were checked in a test chamber. The I-index was used to characterize the movement data before (0~1 h) and after (1~2 h) the treatments in laboratory conditions. The slopes of the frequency distribution of I-index in semi-log scale decreased significantly, and the test populations appeared to be more dispersed with a lower degree of aggregation after the treatments. The index was feasible in indicating decrease in the ability of the specimens to keep desirable distances with neighbor individuals under chemical stress and showed a possibility of monitoring presence of toxic chemicals in environment through group behavior measurement.

• Journal of Sensor Science and Technology
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• v.7 no.5
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• pp.342-349
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• 1998

A multipurpose TLD readout system for radiation dosimetry and thermoluminescence study is constructed and its characteristics are investigated. The thermoluminescent lights are measured by a PM tube and the current-to-frequency converter. TLDs are heated by platinum heater and the heating rate is linearly varied. Measurement of the glow curve and control of the whole system have been done by a personal computer equipped with an interface board. The automatic gain control can be done by the control software. The lower detection limit of the system is about $10\;{\mu}Gy$ and dose response is linear.

• Journal of the Korean Society of Food Culture
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• v.15 no.4
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• pp.241-251
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• 2000

This study was designed to develop the education and training program of dietitians and cooks in contracted foodservice management company. The instruments were developed by reviewing extensive literatures on education programs and by interviewing with dietitians and cooks who were working in contracted foodservice management company. A total of 400 questionnaires were hand delivered at the fourteen contracted foodservice management companies by designated coordinators. A total of 286 questionnaires were usable; resulting in a 70.0% response rate. Statistics data analysis was completed using the SPSS for frequency analysis, reliability, mean value, t-test and ANOVA. The results of this study were summarized as follows: 1. The dietitians wanted to take a management course. The cooks wanted to take a culinary education. The dietitians and cooks took an emphasis on service education, foodborne illness & HACCP and sanitation & safety. Service as well as the taste of food and sanitation was emphasized according to the flow of customer satisfaction. 2. Contracted foodservice management company should provide dietitians and cooks with an education for the job to accomplish customer satisfactions.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2114-2117
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• 2014

Joint pain is generally a common disorder not only for the old aged people but also for the immunocompromised patients. The present proposed study reveals the presence of inflammatory diseases in joint generally diagnosed by removing synovial fluid and changes in the volume and composition are examined for the presence of WBC and crystals. This study implement a non-invasive approach to identify the changes in joint fluid by measuring the changes in electrical property of the synovial tissue under the influence of electrical current signal with frequency range between 100 kHz to 300 kHz. The response of tissue for the current signal was measured in terms of potential drop across the tissue. The hardware system design consists of input and output sections. The input section which applies current signal to upper limb joint region is made of ICL8038 function generator IC with amplifier and voltage to current converter. The output section picks voltage variation using metal surface electrode, amplifier, ADC, PIC microcontroller and LCD interface. 100 patient inclusive of normal and disease affected patients where examined for upper limb synovial fluid variation and inflammatory diseases were identified.

• The Journal of Korean Medicine
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• v.41 no.3
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• pp.247-259
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• 2020

Objectives: This review aims to investigate clinical studies related to bee venom pharmacopuncture for cancer patients and to analyze the research trend for further study. Methods: We searched for clinical studies using bee venom pharmacopuncture therapy on patients with cancer through the electronic databases including Pubmed, Cochrane library, OASIS, KISS, NDSL, and KMBASE. There was no restriction on language and publication date, and after selection/exclusion process, the study design, target disease, intervention details including acupoints, treatment frequency and period, outcomes, study results and adverse events were extracted. Results: Thirteen clinical studies were finally selected. There were a randomized controlled trial RCT about the effect of sweet bee venom pharmacopuncture on cancer-related pain, and three case series about chemotherapy-induced peripheral neuropathy. In case reports, there were nine studies about oligodendroglioma, plexiform neurofibroma, breast cancer, prostate cancer, lung cancer, urachal adenocarcinoma, malignant melanoma, and atypical squamous cells of undetermined significance. The bee venom therapy affected the improvement of outcomes such as symptoms, quality of life, tumor response, and lab findings. Conclusions: The present study found that bee venom therapy is applicable to the treatment of cancer patients, and showed some effect on various symptoms. However, due to insufficient number and quality of studies, well designed and high-quality clinical trials are necessary to confirm the effectiveness and safety of bee venom pharmacopuncture therapy in patients with cancer.

• Structural Engineering and Mechanics
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• v.44 no.2
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• pp.179-196
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• 2012

An eigenspace projection clustering method is proposed for structural damage detection by combining projection algorithm and fuzzy clustering technique. The integrated procedure includes data selection, data normalization, projection, damage feature extraction, and clustering algorithm to structural damage assessment. The frequency response functions (FRFs) of the healthy and the damaged structure are used as initial data, median values of the projections are considered as damage features, and the fuzzy c-means (FCM) algorithm are used to categorize these features. The performance of the proposed method has been validated using a three-story frame structure built and tested by Los Alamos National Laboratory, USA. Two projection algorithms, namely principal component analysis (PCA) and kernel principal component analysis (KPCA), are compared for better extraction of damage features, further six kinds of distances adopted in FCM process are studied and discussed. The illustrated results reveal that the distance selection depends on the distribution of features. For the optimal choice of projections, it is recommended that the Cosine distance is used for the PCA while the Seuclidean distance and the Cityblock distance suitably used for the KPCA. The PCA method is recommended when a large amount of data need to be processed due to its higher correct decisions and less computational costs.

• Structural Engineering and Mechanics
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• v.44 no.5
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• pp.663-680
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• 2012

Previous major earthquakes revealed that most damage of the buried segmented pipelines occurs at the joints of the pipelines. It has been proven that the differential motions between the pipe segments are one of the primary reasons that results in the damage (Zerva et al. 1986, O'Roueke and Liu 1999). This paper studies the combined influences of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines. The heterogeneous soil deposits surrounding the pipelines are assumed resting on an elastic half-space (base rock). The spatially varying base rock motions are modelled by the filtered Tajimi-Kanai power spectral density function and an empirical coherency loss function. Local site amplification effect is derived based on the one-dimensional wave propagation theory by assuming the base rock motions consist of out-of-plane SH wave or combined in-plane P and SV waves propagating into the site with an assumed incident angle. The differential axial and lateral displacements between the pipeline segments are stochastically formulated in the frequency domain. The influences of ground motion spatial variations, local soil conditions, wave incident angle and stiffness of the joint are investigated in detail. Numerical results show that ground motion spatial variations and local soil conditions can significantly influence the differential displacements between the pipeline segments.