Jungchul Park

Presenting a Submenu Window for Menu Search on a Cellular Phone

This study proposes a submenu window as a navigation aid for mobile Internet access on a cellular phone. The submenu window presents child-level menu items along with their upper-level menu. The effectiveness of the submenu window was investigated in an experiment. The factors manipulated in the experiment include the types of submenu window, age of participants, and timing of presenting the submenu. Task completion time, number of button clicks, and subjective preference were measured while the participants were performing target search tasks. The results showed that they preferred the separate submenu window. The best performance was obtained when the submenu immediately followed the selection of its parent menu. In addition, the participants in their 20s found a target menu item with fewer button clicks than did the teenagers. The separate submenu window with no delay was recommended in terms of both performance and subjective preference. The design guidelines for submenu windows on a small-screen device are also provided. The results of this study are expected to be applicable to menu-driven interfaces of many small-screen devices such as digital cameras and personal digital assistants.

Measuring flare and its effect on process latitude

In this paper we report on the method of measuring the magnitude of scattered light, flare in a stepper lens and its effect on the overall process latitude. By measuring the required energy to clear large square patterns, it was possible to calculate the amount of scattered light in a lens system. When the size of a square pattern is larger than 10 micrometers , the magnitude of scattered light saturates to be independent on the size. But it gradually increases as the clear to dark area ratio of the mask increases. Simulation result shows that scattered light degrade the MTF of an aerial image and when it becomes larger than 2%, the process latitude start to decrease. Measuring scattered light with different mask opening ratio reveal that it exceed 2% when the mask opening ratio is around 70%. There was no significant difference in scattered light between different DUV scanner tools when the patterns were larger than 10 micrometers , but some difference was observed at the smaller patterns. Overall process latitude were measured with masks with different opening ratio. The exposure latitude decreased as mask opening ratio increase for positive photoresist, depth of focus was not significantly affected at increase of 20 to 50%. But we can observe 0.2 micrometers of focus margin decrease for mask open ratio change from 50 to 80% for both 260 and 240 nm patterns. So if we assume that there is no difference in process performances between positive and negative photoresists, using a negative photoresist will give more process latitude.

Development of a Workload Assessment Model for Overhead Crane Operation

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

Usability of adaptable and adaptive menus

This study investigates the usability of different adaptable and adaptive menu interfaces in a desktop environment. A controlled experiment was conducted to compare two different adaptive menus and one adaptable menu with a traditional menu. The two adaptive menus include an adaptive split menu that moves frequently used menu items to the top, and an adaptive highlight menu that automatically boldfaces frequently used menu items. Target selection times and the number of errors were recorded while the participants were performing menu selection tasks. Subjective satisfaction including perceived recognizability, perceived efficiency, and overall preference were also measured. The results showed that the adaptable menu outperformed the other menus in terms of both the performance and the satisfaction. The adaptive split menu was not as efficient as its theoretical prototype, especially when the selection frequency changed. The adaptive highlight menu, newly proposed in this study, was not significantly better than the traditional menu in terms of the selection time. However, it was preferred by the users since it helped them select frequently used items and was much less sensitive to the variations of selection frequency.

A framework for evaluating the usability of spoken language dialog systems (SLDSs)

Usability evaluation is now considered an essential procedure in developing a spoken language dialogue system (SLDS). This paper proposes a systematic framework for evaluating the usability of SLDSs. The framework consists of what to evaluate and how to evaluate. What to evaluate includes components, evaluation criteria, and usability measures to evaluate various aspects of SLDSs. With respect to how to evaluate, a procedure for developing scenarios and scenario-based evaluation methods are introduced. In addition, a case study, in which the usability an SLDS was evaluated, was conducted to validate the proposed framework. The results of the case study showed successfully the usability level, usability problems, and design implications for further development. The framework proposed in the study can be practically applied to usability evaluation of SLDSs.

Input Performance of the Old Adults in Touch Interface

ABSTRACT In order to design a touch interface for the elderly, human performance of input tasks on the touch screen was investigated by the laboratory experiment. Input times and input errors were measured in the experimental conditions that were changed according to age, key size, interkey space and input tool(finger or stylus pen). In the most of all experimental conditions, the task performance of the elderly was lower than that of the young. However, there were significantly different performance patterns between both groups. As the difficulty of task was getting higher, the task performance of the elderly was sharply decreased; pressing small key button by finger sharply increased input time and error rate, compared to that of the young. Therefore, the square key size suitable to the elderly may be over 8.0×8.0mm. While the interkey space did not influence to the input task performance of the young, the task performance of the elderly was influenced. The elderly showed big difference of task performance according to input tool. However, the young were less influenced by input tool.Keywords: Old adults, Touch, Interface design, Key size, Input

Integration of Adaptable and Adaptive Approaches for Interface Personalization Through Collaborative Menu

This article examines different user-system collaboration models in the adaptation of a menu interface. Four collaboration models were implemented on a prototype of mobile phone menu: (a) basic collaboration with no system support (for user adaptation) and no user control (over system adaptation), (b) system support only, (c) user control only, and (d) system support plus user control. The prototype mobile phone menu includes a hotlist (a quickly accessible collection of menu items) as well as a hierarchical menu. The hotlist is collaborative, because it combines adaptable and adaptive approaches by allowing both the user and the system to manage the items in it. A controlled experiment compared different types of collaborative menus in order to investigate the effects of system support and user control. Twenty participants performed menu selection tasks in the experiment, and both performance and subjective measures were taken. The results showed that, in a certain condition, the system support and the user control improved the user performance when applied independently, but their effects were not additive. Although the effects disappeared when the selection frequency distribution changed, the system support was preferred by most of the users. The advantages and disadvantages of the collaborative menus and implications for the adaptation of menus are discussed.

A Comparison of Visual Occlusion Methods: Touch Screen Device vs. PLATO Goggles

Objective: This study compares two visual occlusion methods for the evaluation of in-vehicle interfaces. Background: Visual occlusion is a visual demand measuring technique which uses periodic vision/occlusion cycle to simulate a driving(or mobile) environment. It has been widely used for the evaluation of in-vehicle interfaces. There are two major implementation methods for this technique: (1) occlusion using PLATO(portable liquid crystal apparatus for tachistoscopic occlusion) goggles; (2) occlusion using a software application on a touchscreen device. Method: An experiment was conducted to examine the visual demand of an in-vehicle interface prototype using the goggle-based and the touchscreen-based occlusion methods. Address input and radio tuning tasks were evaluated in the experiment. Results: The results showed that, for the radio tuning task, there were no significant differences in total shutter open time and resumability ratio between the two occlusion conditions. However, it took longer for the participants to input addresses with the touchscreen-based occlusion. Conclusion & Application: The results suggest that touchscreen-based method could be used as an alternative to traditional, gogglebased visual occlusion especially in less demanding visual tasks such as radio tuning.

Cursor Capturing Functions as an Aid for Target Selection in Mouse Operation

This study proposed two cursor capturing functions in mouse operation. One is to move the cursor over a target instantaneously (jumping function) when the cursor reaches around the target, and the other is to move the cursor over the target gradually (gravity function). The effects of cursor capturing functions were examined and compared with the normal condition (i.e., without the functions). Task completion times, number of errors, and subjective preferences were evaluated. The results showed that the gravity function had faster movement times and fewer errors than the normal condition. The gravity function was more preferred than the jumping and the normal condition.

Deep-UV positive-tone dry-development process using chemically amplified resist and its application to 256 Mbit DRAM

Top surface imaging and subsequent dry development were known to improve lithographic performance. Since negative working DESIRE process was introduced, several alternative methods have also been proposed. We propose a new resist system (SS-201), which is positive working in DUV lithography. We characterized this resist in view of top surface imaging (TSI) process and applied it to our 256 mega bit DRAM test device. Since conventional TSI process has a swelling problem by nature, WEBS (wet development before silylation) technique is proposed to minimize swelling. Special attention was focused on contact holes since our TSI process enables positive tone mask, which has a definite advantage in reducing potential defects in mask making.