• The Korean Journal of Ecology
• /
• v.21 no.3
• /
• pp.269-276
• /
• 1998

The study of the Rana plancyi, was done during the calling period at a pond in Osong, Chungbuk, Korea from May to the middle of August of 1996 and 1997. Five basic types of call-A, B, C, D, E, - were identified in Rana plancyi according to the structure of call types. The structure of A type call has only one pulse, B type call has two pulses and C, D type call has one separated pulse which is called introductory call and pulse group as follow it. On the other hand, E type call has 3-6 separate pulses. The interval between introductory call and pulse group is $0.73{\pm}0.29$ s(n=159) in C type call and $0.60{\pm}0.21$ s (n=48) in D type call. The number of pulses in the pulse group is $30.08{\pm}8.69$ in C type call and $15.78{\pm}2.40$ in D type call. An increase in water temperature induces a decrease in C and D type call duration (C type call r= -0.4153, p<0.001, D type call r=-0.7064, p<0.001). In case of C and D type call, the interval between introductory call and pulse group influenced more call duration than pulse group duration. We regarded A, B type call as a territorial call and C, D type call as a mating call and we recognized that E type call has the function of threat or alarm.

• The Korean Journal of Zoology
• /
• v.39 no.2
• /
• pp.207-214
• /
• 1996

Five call types of the genus Hyla in habitats around South Korea were classified according to some attributes of their advertisement calls (note duration, note intenral, dominant frequency, sonagram patterns. Among the call types, the E-type was more distinctive than the other call types in that it had a metal sound and much longer note duration and note intenral. This result indicated that some divergence had occurred in the advertisement call of the genus Hylo, though this was found in alimited number of regions and its occurrence was small.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.14 no.4
• /
• pp.87-93
• /
• 2006

The black-tailed gull chicks, Larus crassirostris, recognize various adult voice signal base on the simple patterns. We investigated behavior change in black-tailed gull chicks through physical manipulation of mew call. They were playback in four situations differing in physical character: 1) frequency manipulation only, 2) duration manipulation only, 3) call intensity(dB) manipulation only, and 4) call interval manipulation only. We observed occurrence of different response of the chicks, which were categorized into two behaviors(hidden and return behavior). The manipulated frequency, duration, and intensity were directly correlated. The chicks exposed to only manipulated call interval(0.5, 1sec) made significantly more hidden and return behavior. Adult black-tailed gull only increased flight time on manipulated call interval. The results suggest that black-tailed gulls use short call interval for alarm signal. The analysis of alarm signal provides an important on basic study of bird strike.

• 한국HCI학회:학술대회논문집
• /
• 2006.02a
• /
• pp.579-586
• /
• 2006

모바일 환경에서 휴대폰을 사용하다 보면 무의식적으로 전화를 받지 못하는(Missing call) 상황이 빈번하게 일어난다. 휴대폰에서는 기본적으로 시각 청각 촉각의 다중양식 피드백(Multimodal feedback)을 제공하고 있음에도 불구하고, 이렇게 Missing call 이 발생하는 현상에는 여러 가지 다양한 원인이 존재할 것이다. 본 연구에서는 이러한 원인을 찾기 위해 모바일 환경 내 휴대폰 사용자 행동연구를 실시하여 일반적인 휴대패턴을 분석하고, Missing call과 관련하여 주로 설정하는 수신모드와 휴대패턴의 상호영향을 연구하고자 하였다. 본 연구결과, 모바일 환경에서 휴대폰 수신 탐지능력에는 인지심리학적(감각과 주의관련), 환경적, 행동학적 요인이 영향을 미칠 수 있는 것으로 나타났다. 또한 모바일 환경에서 주로 사용하는 수신모드인 진동모드 설정시, 휴대폰 사용자가 속한 환경에 다른 요인들이 복합적으로 존재할 경우 휴대폰 수신에 대한 탐지만족도가 감소함을 확인할 수 있었다.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.23 no.3
• /
• pp.135-151
• /
• 1998

The demand of large capacity in coming cellular systems makes inevitable the deployment of small cells, rendering more frequent handoff occurrences of calls than in the conventional system. The key issue is then how effectively to reduce the chance of unsuccessful handoffs, since the handoff failure is less desirable than that of a new call attempt. In this study, we consider the control policies which give priority to handoff calls by limiting channel assignment for the originating new calls, and allow queueing the new calls which are rejected at their first attempts. On this system. we propose the problem of finding an optimal call control strategy which optimizes the objective function value, while satisfying the requirements on the handoff/new call blocking probabilities and the new call delay. The objective function takes the most general form to include such well-known performance measures as the weighted average carried traffic and the handoff call blocking probability. The problem is formulated into two different linear programming (LP) models. One is based on the direct employment of steady state equations, and the other uses the theory of semi-Markov decision process. Two LP formulations are competitive each other, having its own strength in the numbers of variables and constraints. Extensive experiments are also conducted to show which call control strategy is optimal under various system environments having different objective functions and traffic patterns.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1998.10a
• /
• pp.173-179
• /
• 1998

This paper proposes a new call admission control scheme utilizing an inverse fuzzy vector quantizer(IFVQ) and neural net, which combines benefits of IFVQ and flexibilities of FCM(Fuzzy-C-Menas) arithmatics, to decide whether a requested call that is not trained in learning phase to be connected or not. The system generates the estimated traffic pattern of the cell stream of a new call, using feasible/infeasible patterns in codebook, fuzzy membership values that represent the degree to which each pattern of codebook matches input pattern, and FCM arithmatics. The input to the NN is the vector consisted of traffic parameters which is the means and variances of the number of cells arriving inthe interval. After training(using error back propagation algorithm), when the NN is used for decision making, the decision as to whether to accept or reject a new call depends on whether the output is greater or less then decision threshold(+0.5). This method is a new technique for call admi sion control using the membership values as traffic parameter which declared to CAC at the call set up stage, and is valid for a very general traffic model in which the calls of a stream can belong to an unlimited number of traffic classes. Through the simmulation. it is founded the performance of the suggested method outforms compared to the conventional NN method.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.27 no.3_4
• /
• pp.429-440
• /
• 2003

The purpose of this study is to classify the types of men's shoulders through the criteria which represent the characteristic of men's shoulders. In addition, we introduce new bodice patterns depending on our classification. We have the fo11owing conclusions based on our sample size of 200 men's shoulders: 1. The result of factor analysis indicates that six factors are extracted and they consist of 62.3% of total variance. We then choose three factors as standard items for our classification of the shape of men's shoulders. 2. We divide the shape of shoulders into three categories: bent, slopeness, and thickness. Each category is divided into three subcategories. (a) Bent: If one's shoulders are bent forward or backward, then we call them front or back-bent type. Otherwise, they are called standard-bent type. (b) Slopeness: If one's shoulders have an easy or steep slope, then we call them easy or steep slope type. Or else, they are called standard slope type. (c) Thickness: If one's shoulders are thick or thin, then we call them thick or thin type. Otherwise, we call them standard thick type. 3. According to the frequency based on our data entries of 200 men's shoulders, we introduce five new types of men's shoulders. 76.5% of examined men's shoulders belong to one of these five types: (a) 8.0% of standard slope and back-bent type: (b) 9.5% of easy slope and standard-bent type; (c) 45.5% of standard slope and standard-bent type; (d) 5.5% of steep slope and standard-bent type; (e) 8.0% of standard slope and back-bent type. 4. The suitability of new basic bodice patterns based on the types of men's shoulders are demonstrated by the high approval rate of the subjects who participate in testing.

• Journal of Environmental Science International
• /
• v.19 no.1
• /
• pp.61-68
• /
• 2010

In this study, we analyzed the pulse-duration, pulse-interval and peak-frequency of echolocation call in three species as Rhinolophus ferrumequinum, Pipistrellus abramus, and Myotis macrodactylus. The peak frequency and pulse duration for above mentioned species were 69 kHz, 47 kHz and 49 kHz and $69.39{\pm}8.76\;ms$, $4.95{\pm}0.77\;ms$ and $3.09{\pm}0.48\;ms$ for R. ferrumequinum, P. abramus and M. macrodactylus, respectively. The pulse intervals for R. ferrumequinum, P. abramus and M. macrodactylus were $103.61{\pm}9.05\;ms$, $67.59{\pm}3.47\;ms$ and $66.35{\pm}4.96\;ms$, respectively. The pulse pattern of R. ferrumequinum was setting into a short FM call and linked to long CF call and went through the short FM call again. The pulse pattern of M. macrodactylus was comprised with serial short FM call and the CF call was not checked up in accordance with the spectrogram analysis. The long FM call and short CF call got join together for the P. abramus and the peak frequency was checked up at the pulse ending as CF call.

• Research in Community and Public Health Nursing
• /
• v.33 no.1
• /
• pp.128-138
• /
• 2022

Purpose: This study aimed to identify the factors influencing the wellness of call center employees. Methods: From December 2018 to October 2019, a cross-sectional study was conducted with 155 workers recruited from the call centers in Seoul, South Korea. Data were collected using self-administered questionnaires. The questionnaires were used to measure the following scales: Korean occupational stress scale, emotional labor scale, work-life balance scale and wellness scale. Using the SPSS 26.0 program, the descriptive statistics, independent t-test, ANOVA, correlation analysis, and multiple regression analysis were conducted. Results: The mean score of the wellness level of call center employees was 3.05 out of a maximum of 5.00. More wellness level of call center employees was associated with gender, psychiatric diagnosis, and call characteristics. A multiple regression analysis indicated that the total scores on the wellness scale were predicted by call characteristics, occupational stress and work-life balance, with an explanatory power of 42.2%. Conclusion: Study findings show that it is necessary to promote wellness in call center workers with differentiated strategies according to call characteristics, occupational stress and work-life balance. This implies that it is necessary to understand the call characteristics and patterns of workers and to provide an innovative wellness program tailored to individual characteristics for an effective management of the emotional labor and occupational stress.

• Journal of Forest and Environmental Science
• /
• v.32 no.1
• /
• pp.99-102
• /
• 2016

Echolocation call structure and intensity were measured from the Malaysian Myotis muricola, which were recorded from the hand-released bat. The Malaysian M. muricola produced typical FM call pattern of the genus Myotis, producing steep, downward frequency-modulated calls. The average PF of calls is $64.39{\pm}1.33(kHz)$. Discrete PF patterns of two types are found, which consist of 63.39 kHz and 66.15 kHz. The averages of SF and D are $126.07{\pm}3.37kHz$ and $2.14{\pm}0.29ms$, respectively. There are various IPI lengths with average of $42.97{\pm}12.68ms$. A pulse consists of two harmonies which consist of the first harmony with wider bandwidth and the second harmony with narrower bandwidth. The PF of the first harmony is higher than that of the second harmony. The typical FM call structure, with two harmonies and wide bandwidth, would be highly related to fast flying and wide screening in the dense forests.